01
Give new hires a clear starting point.
Replace scattered instruction with a step-by-step path through safety, inspection, wiring, and routine service. Assign training and see who is ready for the next level.
TRAILER TECHNICIAN TRAINING & CERTIFICATION
Trailer Technician
Training & Certification
Less guesswork. Stronger technicians.
A more capable shop.
From the first bearing inspection to advanced diagnostics. Build skills with manufacturer-based lessons, real circuit practice, and a clear three-level training path.
SELF-PACED · PHONE, TABLET & DESKTOP
BUILT WITH SERVICE MANUALS FROM
DexterLippertBostailKTICurtDemco
Independent training. Manufacturer names identify source materials, not sponsorship or endorsement.
BUILT FOR THE SERVICE BAY
The real cost of guesswork.
A repeatable training process helps your team make better service decisions. No shortcuts. No promises of instant expertise.
02
Build the diagnostic habit.
Practice voltage drop, magnet resistance, and circuit faults before working on customer equipment. Train technicians to test the cause, not just replace the part.
03
Know where your team stands.
See verified scores in one skills matrix. Set due dates, spot training gaps, and keep earned certificates connected to each technician’s account.
A LADDER. NOT A PILE OF COURSES.
Start with the basics.
Earn your way to master.
View the full curriculumLEVEL 01
Basic Technician
SAFE SERVICE & INSPECTION
Build dependable habits in shop safety, trailer anatomy, bearings, suspension, wiring, and routine inspection.
11 modules · 111 lessons
100-question final
LEVEL 02
Advanced Technician
SYSTEM DIAGNOSTICS & REPAIR
Trace electrical faults, service drum and disc brakes, troubleshoot ABS and hydraulics, and diagnose alignment problems.
10 modules · 104 lessons
150-question final
LEVEL 03
Master Technician
ROOT CAUSE & SHOP LEADERSHIP
Develop failure-analysis skills, structural repair knowledge, air-brake expertise, and a repeatable approach to quality control.
6 modules · 60 lessons
250-question final
25 questions per module quiz. 80% to pass quizzes and finals. Complete each level before the next unlocks; the Master final covers all core levels.
AFTER ADVANCED / BRAND ADD-ONSDexter Axles & BrakesLippert Axles, ABS & SuspensionKTI & Hydraulic BrandsCoupler & Hitch BrandsBostail Axles & Hoists
KNOW WHAT GOOD LOOKS LIKE.
Find the fault.
Before the comeback.
An open magnet. A shorted lead. A bad ground. Practice the measurements that separate a diagnosis from a guess.
Readings anchored to manual specifications
3.2 Ω cold resistance and 3.0 A operating current per healthy 12 × 2-inch magnet, with modeled wiring losses and warm-magnet resistance.
A daily diagnostic companion
Describe a symptom and explore AI-suggested steps grounded in course content and reference specifications. Verify suggestions before service.
Open AI DiagnoseINVEST IN THE PERSON. OR THE WHOLE SHOP.
Training that fits your team.
A clear path for independent technicians, repair shops, and dealerships.
For the independent service bay
Starter Shop
$149/ month
Up to 5 technician seats
- 1 manager account
- Three training levels + brand add-ons
- Team roster and progress tracking
- Training assignments with due dates
For a growing service department
Pro Dealership
$349/ month
Up to 15 technician seats
- Up to 3 manager accounts
- Everything in Starter Shop
- Team skills matrix
- Proposed extra seats: $20 / month
For larger teams and dealer groups
Enterprise & Fleet
$599+/ month
25+ technician seats
- Custom rollout planning
- Three training levels + brand add-ons
- Multi-location reporting — planned
- Dedicated account support — planned
Prices in USD. Shop plans are bought by the shop owner or manager after registering the shop. Enterprise & Fleet is quoted individually.
THE SPEC. WITHOUT THE SEARCH PARTY.
Field Quick Reference
| Category | Item | Spec | Source |
|---|---|---|---|
| Couplers | Curt 30K Rocker — 1" hardware | 400 ft-lbs | Curt |
| Couplers | Curt 30K Rocker — 3/4" hardware | 300 ft-lbs | Curt |
| Couplers | Demco 2-5/16" EZ-Latch repair kits | Kits 5817 & 6008 | Demco |
| Wheels | 1/2" coned steel lug nut | 90–120 ft-lbs | Diamond C |
| Wheels | 5/8" flanged rotating nut | 150 ft-lbs | Diamond C |
| Wheels | 5/8" non-rotating flanged nut | 275–325 ft-lbs | Diamond C |
| Axles | Grease hubs | Lithium Complex NLGI No. 2 | Dexter / Lippert |
| Axles | Oil bath hubs | SAE 80-90W hypoid gear oil | Dexter / Lippert |
| Axles | Spindle castle nut | 50 ft-lbs, back off, finger snug, align cotter pin | Dexter / Lippert |
| Brakes | Break-in procedure | 20–50 applications, 40 → 25 mph | Dexter / Lippert |
| Brakes | Shoe wear limit | 1/16" or less — replace | Dexter / Lippert |
| ABS | Wheel speed sensor air gap | 1.00–1.75 mm (shim) | Lippert ABS |
| ABS | DTC 068Ah | Low battery voltage | Lippert ABS |
| ABS | DTC 0006h | High voltage | Lippert ABS |
| Hydraulics | KTI KWR-005 – KWR-008 pairing code | 123456 | KTI |
| Hydraulics | KTI low-voltage alarm | < 9 V | KTI |
| Hydraulics | Tuff Wireless output modes | Power Down / Gravity Down | Tuff |
| Suspension | 2K — 3/8" U-bolt nuts | 35 ft-lbs | Lippert QR-018 |
| Suspension | 3.5K — 1/2" U-bolt nuts | 50 ft-lbs | Lippert QR-018 |
| Suspension | 5.2K — 9/16" U-bolt nuts | 65 ft-lbs | Lippert QR-018 |
| Suspension | 6K–8K — 9/16" U-bolt nuts | 90 ft-lbs | Lippert QR-018 |
| Suspension | 10K — 5/8" U-bolt nuts | 95 ft-lbs | Lippert QR-018 |
| Suspension | 12K–16K — 5/8" U-bolt nuts | 115 ft-lbs | Lippert QR-018 |
| Suspension | Double-eye spring eye / equalizer / shackle | 30–50 ft-lbs | Lippert QR-018 |
| Suspension | 3.5K–10K torsion 5/8" bolts | 120–150 ft-lbs | Lippert QR-018 |
| Wheels | 17.5" dual flange nut M22 (final) | 450–500 ft-lbs | Lippert QR-018 |
| Brakes | Brake mounting 2K–7K / 8K–16K | 35–55 / 55–80 ft-lbs | Lippert QR-018 |
| Brakes | Magnet amperage | 3.0 A per magnet | Lippert Axle Manual |
| Brakes | Drum replace limit | .090" wear/scoring | Lippert Axle Manual |
| Brakes | Burnish target temperature | 350–400 °F | Lippert TI-086 |
| Axles | Oil cap | 25 ft-lbs | Lippert QR-018 |
| Hydraulics | KTI primary relief valve | 3200 psi (factory set) | KTI Troubleshooting |
| Hydraulics | KWR-003 fob programming shunt | Pins 1–2 program / 2–3 hold | KTI Wireless |
| Schedule | Grease repack | 12,000 mi / 12 months | Lippert / Diamond C |
| Wiring | 7-way #1 White | Common ground | Dexter wiring |
| Wiring | 7-way #2 Blue | Electric brakes | Dexter wiring |
| Wiring | 7-way #3 Green | Tail / running / license | Dexter wiring |
| Wiring | 7-way #4 Black | Battery charge +12 V | Dexter wiring |
| Wiring | 7-way #5 Red | Stop & left turn | Dexter wiring |
| Wiring | 7-way #6 Brown | Stop & right turn | Dexter wiring |
| Wiring | 7-way #7 Yellow | Auxiliary | Dexter wiring |
| Wiring | 9-way #8 Grey / #9 Orange | Auxiliary | Dexter wiring |
| Breakaway | Brakes applied after breakaway | ≥ 15 minutes | 49 CFR 393.43 |
| Breakaway | Pin pull force | ~40 lb | Cequent TB11-06 |
| Breakaway | Max test time with pin pulled | 2 minutes | Dexter |
| Breakaway | Minimum battery (EOH) | 9 Ah | Dexter |
| Surge | Surge actuator fluid | DOT 3 or DOT 4 | Dexter OM-A-160 |
| Tires | DOT date code | Last 4 digits = week + year | USTMA |
| Tires | Replace at tread depth | 2/32" | Hankook ST |
| Tires | Pressure check | Cold, monthly & before trips | Hankook ST |
| Welding | Stick electrode | AWS E-7018 (oven dried) | Hendrickson L64 |
| Welding | MIG wire | ER-70S-6 (ER-70S-3 optional) | Hendrickson L64 |
| Welding | Max fit-up gap | 1/16" | Hendrickson L64 |
| Chains | Safety chain strength | ≥ gross weight towed | 49 CFR 393.70 |
| Doors | Zero-G spring adjust socket | 3/4" — CW heavier assist | MORryde |
| Roof | Lap sealant bead | 1/4"–3/8" (Dicor 501LS) | Dicor |
| Decking | Apitong life / reseal | 15–20 yrs / annually | Heavy Duty Journal |
| DOT | Clearance & ID lamps required | Width ≥ 80" | 49 CFR 393.11 |
| DOT | Stop & tail lamp color | Red (amber prohibited) | 49 CFR 393.11 |
| Hoist | Hinge/hoist grease | EP3 every 6 months | Scissor hoist manual |
| Hoist | Safety arm | Unloaded body only | Scissor hoist manual |
| Safety | Lockout/Tagout | 29 CFR 1910.147 | OSHA |
| Warranty | Top Hat dealer claim deadline | 10 days from discovery | Top Hat 2025 |
| Brakes | First brake adjustment, page 42 | 200 miles | Bostail 8K Axle Manual |
| Brakes | Subsequent brake adjustment, page 42 | Every 3,000 miles, or as use and performance require | Bostail 8K Axle Manual |
| Brakes | Brake lining replacement threshold, page 39 | Less than 1/16 inch | Bostail 8K Axle Manual |
| Brakes | Four-brake wiring, 30–50-foot connector-to-axle run, page 14 | Minimum 10 AWG | Bostail 8K Axle Manual |
| Brakes | Minimum magnet voltage with 12 V controller output, page 47 | 10.5 V | Bostail 8K Axle Manual |
| Brakes | 12 x 2-inch brake nominal warm-magnet current at specified test conditions, page 47 | 3.0 A per magnet at 12 V | Bostail 8K Axle Manual |
| Axles | Section 9.8 initial castle-nut tightening, page 30 | 50 ft-lbs while rotating hub; release torque and finish finger tight | Bostail 8K Axle Manual |
| Suspension | 8K 1/2-20 U-bolt torque, page 60 | 60–90 ft-lbs | Bostail 8K Axle Manual |
| Suspension | Listed spring eyebolt and 8K equalizer bolt requirement, page 60 | 0–1/16 inch end play | Bostail 8K Axle Manual |
| Wheels | 8K lug-nut torque, page 60 | 140–160 ft-lbs | Bostail 8K Axle Manual |
| Wheels | New-trailer lug-nut check and retorque mileages, page 10 | 25, 50, and 100 miles | Bostail 8K Axle Manual |
| Hydraulics | Hoist chart hydraulic relief-pressure basis, page 1 | 3,200 psi | Bostail Power Hoist Capacity Chart |
| Hoists | Minimum vertical rear-hinge-pivot-to-floor height for chart basis, page 1 | 3 inches | Bostail Power Hoist Capacity Chart |
| Hoists | PH310, 8-foot body, 24-inch overhang, 45°, page 1 | 5.5 tons under the stated general-guide chart assumptions | Bostail Power Hoist Capacity Chart |
| Hoists | PH616-6, 12-foot body, 24-inch overhang, 45°, page 4 | 15.7 tons under the stated general-guide chart assumptions | Bostail Power Hoist Capacity Chart |
| Axles | Minimum tire-to-tire clearance when determining axle spacing | 1 inch under every loading condition | applications-manual-(lit-008-00) |
| Axles | Maximum load on the heavier side when specifying axles | One-half of rated axle capacity | applications-manual-(lit-008-00) |
| Brakes | Electric brake burnishing before synchronization | 20-30 applications with approximately a 20 mph speed reduction and cooling between applications | LDServiceOnline |
| Brakes | Electric brakes without self-adjustment: adjustment interval | First 200 miles, then every 3,000 miles, or as required | LDServiceOnline |
| Brakes | Electric drum lining replacement thickness | 1/16 inch or less | LDServiceOnline |
| Brakes | 7 x 1-1/4-inch electric brake magnet | 2.5 amps; 3.9 ohms | LDServiceOnline |
| Couplers | Specified light-duty surge actuator bolt-on fastener torque | 80 ft-lb for the specified 1/2 x 4-inch Grade 5 bolts and locking nuts | 2024.02LIT75000LightDutyActuatorInstallation |
| Hydraulics | Light-duty surge actuator maximum power-bleeder pressure | 18 psi | 2024.02LIT75000LightDutyActuatorInstallation |
| Hydraulics | Light-duty surge actuator minimum reservoir level during bleeding | Half full | 2024.02LIT75000LightDutyActuatorInstallation |
| Axles | Standard grease-lubricated bearing service interval | 12 months or 12,000 miles | LDServiceOnline |
| Axles | Standard cotter-pin bearing seating torque, not final preload | Approximately 50 ft-lb, followed by loosening and the specified adjustment | LDServiceOnline |
| Axles | Nev-R-Lube spindle-nut torque | 145-155 ft-lb; no further bearing adjustment | LDServiceOnline |
| Axles | 50 mm Nev-R-Lube maximum axial end play | 0.008 inch | LDServiceOnline |
| Brakes | S-cam manual-adjustment test pressure | 80-90 psi | 9-15k complete service manual |
| Brakes | Type 30 air-chamber maximum pushrod stroke | 2 inches | 9-15k complete service manual |
| Axles | Physical bearing inspection interval | 36,000 miles or 12 months, whichever comes first | ccd-0011255 |
| Axles | Wheel-bearing grease consistency | NLGI No. 2 | ccd-0011255 |
| Axles | Wheel-bearing grease minimum dropping point | 446°F (230°C) | ccd-0011255 |
| Axles | ABS hub initial spindle-nut seating torque | 50 ft-lb (68 Nm) while rotating hub; then loosen and finger-tighten until snug | ccd-0011131 |
| Brakes | Brake-lining replacement threshold | 1/16 inch or less | Lippert-Axle-8K-16K-Manual |
| Brakes | Electric brake chart current per magnet | 3.0 amps | Lippert-Axle-8K-16K-Manual |
| Wheels | 16-inch wheel with 1/2-inch studs, final-stage torque | 90–120 ft-lb | ccd-0011134 |
| Wheels | 17.5-inch dual flange-nut wheel with M22 studs, final-stage torque | 450–500 ft-lb | ccd-0011134 |
| Wheels | Post-installation wheel-fastener rechecks | 10, 25 and 50 miles | ccd-0011134 |
| Suspension | 6K–8K axle U-bolt torque, standard guide entry | 90 ft-lb; separate overslung silver-zinc entry applies where equipped | ccd-0011257 |
| Suspension | 7K–8K overslung springs with silver-zinc U-bolts | 145 ft-lb | ccd-0011257 |
| Suspension | 10K axle U-bolt torque | 95 ft-lb | ccd-0011257 |
| Suspension | 12K–16K axle U-bolt torque | 115 ft-lb | ccd-0011257 |
| Suspension | EquaFlex equalizer and shackle nut torque | 30–50 ft-lb, bottomed against the bolt shoulder | ccd-0011275 |
| Suspension | EquaFlex shackle positions after lowering | Upright, approximately 10 o’clock and 2 o’clock | ccd-0011275 |
| Hydraulics | KWR Bluetooth default pairing code | 123456 | KWR-005-English-Instructions |
| Hydraulics | KWR Bluetooth delay before application use after fob release | At least 5 seconds | KWR-005-English-Instructions |
| Hydraulics | KWR Bluetooth application and fob low-voltage lockout | Below 9 V | KWR-005-English-Instructions |
| Hydraulics | KWR Bluetooth inactivity before sleep | 5 minutes | KWR-005-English-Instructions |
| Hydraulics | Remote-kit receiver supply | 9–30 V DC | KTI-Remote-Kit-Instructions |
| Hydraulics | Remote-kit transmitter inactivity shutdown | 15 minutes | KTI-Remote-Kit-Instructions |
| Hydraulics | Remote-kit Micro USB maximum insertion force | 5 lb | KTI-Remote-Kit-Instructions |
| Hydraulics | Five-output receiver programming acceptance indication | Green LED solid for 3 seconds | KTI-Remote-Kit-Instructions |
| Hydraulics | KWR-003 receiver idle shutdown | 20 minutes | KTI-Wireless-Instruction-Manual-1 |
| Hydraulics | KWR-003 stored key-fob capacity | 4; programming a fifth drops the first | KTI-Wireless-Instruction-Manual-1 |
| Hydraulics | Circuits 103 and 111 primary relief | 3200 PSI, factory preset | Hydraulics-Troubleshooting-Manual 2019 |
| Hydraulics | Circuit 111 secondary relief | 1500 psi, factory preset | Hydraulics-Troubleshooting-Manual 2019 |
| Hydraulics | Circuit 111 lowering-valve pilot ratio | 2.5:1 | Hydraulics-Troubleshooting-Manual 2019 |
| Hydraulics | Possible start-solenoid voltage during failure to extend | Below 9.5 V during attempted operation | Hydraulics-Troubleshooting-Manual 2019 |
| Hydraulics | Directional-valve maximum torque | 18 ft-lb | Hydraulics-Troubleshooting-Manual 2019 |
| Couplers | CURT 25050 gross trailer weight capacity | 30,000 lbs. | Curt-Spec-Sheet |
| Couplers | CURT 25050 tongue weight capacity | 7,500 lbs. | Curt-Spec-Sheet |
| Couplers | CURT clear space around coupler during towing | At least 6 inches | Curt-Spec-Sheet |
| Couplers | CURT 1-inch mounting hardware torque | 400 ft-lbs | Curt-Spec-Sheet |
| Couplers | CURT 3/4-inch mounting hardware torque | 300 ft-lbs | Curt-Spec-Sheet |
| Couplers | CURT pivot-point motor oil | SAE 30 wt. | Curt-Spec-Sheet |
| Couplers | Demco ez-Latch ball size covered by manual | 2-5/16 inches | Demco-Coupler-Manual-1 |
| Couplers | Demco hardware recheck interval | Following every 100 hours or 50 miles | Demco-Coupler-Manual-1 |
| Couplers | Demco 5/8-inch Grade 5 standard-bolt chart torque | 150 lb-ft for non-greased, non-oiled threads and heads unless otherwise specified; locking elements require a 5% increase | Demco-Coupler-Manual-1 |
| Couplers | Demco locking-element torque adjustment | Increase chart torque by 5% | Demco-Coupler-Manual-1 |
| Couplers | Demco page 10 mounting callout for 21K | Four 5/8-inch Grade 5 bolts | Demco-Coupler-Manual-1 |
| Couplers | Demco page 10 mounting callout for 18K | Two 5/8-inch Grade 5 bolts | Demco-Coupler-Manual-1 |
| Axles | Lippert physical bearing inspection interval | 36,000 miles or 12 months, whichever comes first | ccd-0011255 |
| Axles | Lippert bearing-grease consistency | NLGI No. 2 | ccd-0011255 |
| Axles | Lippert bearing-grease minimum dropping point | 446°F (230°C) | ccd-0011255 |
| Axles | Lippert bearing-grease minimum viscosity index | 80 | ccd-0011255 |
| Axles | Lippert bearing-grease minimum base-oil viscosity | 695 SUS (150 cSt) at 104°F (40°C) | ccd-0011255 |
| Axles | Dexter capacity range covered by flush rear seal installation | 600–8,000 lb | 059-831-00 HubDrumBearingInstructionSheet |
| Axles | Dexter installed seal flatness | Within 0.010 inch | 059-831-00 HubDrumBearingInstructionSheet |
| Axles | Dexter standard cotter-pin axle initial spindle-nut tightening | Approximately 50 ft-lb while rotating the hub; release torque before final finger adjustment | 059-831-00 HubDrumBearingInstructionSheet |
| Axles | Dexter Nev-R-Lube bearing inspection interval | Every year or 12,000 miles, whichever comes first | 059-831-00 HubDrumBearingInstructionSheet |
| Axles | Dexter Nev-R-Lube 35 mm bearing maximum axial end play | 0.005 inch | 059-831-00 HubDrumBearingInstructionSheet |
| Axles | Dexter Nev-R-Lube 42 mm bearing maximum axial end play | 0.006 inch | 059-831-00 HubDrumBearingInstructionSheet |
| Axles | Dexter Nev-R-Lube 50 mm bearing maximum axial end play | 0.008 inch | 059-831-00 HubDrumBearingInstructionSheet |
| Axles | Dexter Nev-R-Lube self-locking spindle-nut installation torque | 145–155 ft-lb; establishes internal bearing adjustment | 059-831-00 HubDrumBearingInstructionSheet |
| Suspension | Bostail spring and suspension-part inspection, page 52 checklist | Every 3,000 miles | Bostail 8K Axle Manual |
| Suspension | Bostail torsion-suspension inspection | Annually or every 36,000 miles, whichever comes first | Bostail 8K Axle Manual |
| Suspension | Lippert double-eye spring-eye, equalizer, and shackle nuts | 30–50 ft-lb | ccd-0011277 |
| Suspension | Lippert U-bolt torque, 2K axle | 35 ft-lb | ccd-0011257 |
| Suspension | Lippert U-bolt torque, 3.5K axle with 1/2-inch U-bolts | 50 ft-lb | ccd-0011257 |
| Suspension | Lippert U-bolt torque, 5.2K axle | 65 ft-lb | ccd-0011257 |
| Suspension | Lippert U-bolt torque, general 6K–8K entry | 90 ft-lb | ccd-0011257 |
| Suspension | Lippert U-bolt torque, 7K–8K overslung springs with silver zinc U-bolts | 145 ft-lb | ccd-0011257 |
| Suspension | Lippert EquaFlex equalizer and shackle nuts | 30–50 ft-lb, bottomed against bolt shoulders | ccd-0011275 |
| Wheels | Diamond C initial wheel-torque checks | Before first tow and again after about 50 miles | Lug-Nut-Torque-Specs 2023 |
| Wheels | Diamond C 15- or 16-inch steel wheel, 1/2-inch stud, coned nut | 90–120 ft-lb | Lug-Nut-Torque-Specs 2023 |
| Wheels | Diamond C 15-inch aluminum wheel, 1/2-inch stud, coned nut | 90–100 ft-lb | Lug-Nut-Torque-Specs 2023 |
| Wheels | Diamond C 16-inch steel or aluminum wheel, 9/16-inch stud, coned nut | 120–140 ft-lb | Lug-Nut-Torque-Specs 2023 |
| Wheels | Diamond C 17.5-inch single or 16-inch dual steel wheel, 5/8-inch stud, non-rotating flange nut | 275–325 ft-lb | Lug-Nut-Torque-Specs 2023 |
| Wheels | Diamond C 16-inch aluminum wheel, 5/8-inch stud, rotating flange nut | 150 ft-lb | Lug-Nut-Torque-Specs 2023 |
| Brakes | Bostail first brake-clearance adjustment | After 200 miles | Bostail 8K Axle Manual |
| Brakes | Bostail subsequent brake-clearance adjustment | Every 3,000 miles, or as use and performance require | Bostail 8K Axle Manual |
| Brakes | Bostail shoe-lining replacement threshold | Replace below 1/16 inch | Bostail 8K Axle Manual |
| Brakes | Lippert shoe spring-washer release and securing rotation | 90 degrees | ccd-0011259 |
| Brakes | Lippert standard burnishing initial speed | 40 mph, within posted speed limits | Electric-Drum-Brake-Break-In-Period |
| Brakes | Lippert standard burnishing application voltage | Approximately 8–10 volts | Electric-Drum-Brake-Break-In-Period |
| Brakes | Lippert standard burnishing reduced speed | 20–25 mph | Electric-Drum-Brake-Break-In-Period |
| Brakes | Lippert standard burnishing application spacing | 1-mile intervals | Electric-Drum-Brake-Break-In-Period |
| Brakes | Lippert standard burnishing application count | 20–50 applications | Electric-Drum-Brake-Break-In-Period |
| Brakes | Bostail minimum magnet voltage with 12 volts at controller | 10.5 volts | Bostail 8K Axle Manual |
| Brakes | Bostail nominal current per 12 x 2-inch brake magnet | 3.0 amps at 12 volts, normal operating temperature, zero resistor setting, and maximum gain | Bostail 8K Axle Manual |
| Brakes | Bostail minimum wire size for four brakes over a 30–50-foot connector-to-axle run | 10 AWG | Bostail 8K Axle Manual |
| Diagnostic power cycling | Complete power-removal wait | Lippert: 10 seconds with every power source disconnected; values vary by maker. | Lippert-Anti-Lock-Braking-System, page 3 |
| Supply-voltage diagnosis | Low-voltage harness comparison | Lippert: harness voltage 2 volts or more below battery voltage follows the harness-replacement branch; values vary by maker. | Lippert-Anti-Lock-Braking-System, page 4 |
| Supply-voltage diagnosis | Battery overvoltage correction branch | Lippert: 16 volts or higher, below the separate 30-volt branch, requires correcting the overvoltage source and retesting; values vary by maker. | Lippert-Anti-Lock-Braking-System, page 5 |
| Supply-voltage diagnosis | Battery overvoltage module-replacement branch | Lippert: 30 volts or higher requires source correction, ABS module replacement, and retesting; values vary by maker. | Lippert-Anti-Lock-Braking-System, page 5 |
| Mechanical sensor diagnosis | Maintenance rotation that can set a mechanical DTC | Lippert: rotating a single wheel for longer than 10 seconds can set the code; values vary by maker. | Lippert-Anti-Lock-Braking-System, page 13 |
| Mechanical sensor diagnosis | Wheel-speed sensor air gap | Lippert: 1.00-1.75 mm; values vary by maker. | Lippert-Anti-Lock-Braking-System, page 13 |
| Mechanical sensor diagnosis | Towing verification | Lippert: over 30 mph for at least one mile before checking DTC status at the specified chart branches; values vary by maker. | Lippert-Anti-Lock-Braking-System, page 13 |
| Hub installation | Initial spindle-nut torque | Lippert: 50 ft-lb (68 Nm) while rotating the hub, followed by loosening and finger-tightening until snug; values vary by maker. | ccd-0011131, page 7 |
| Wheel installation | Stages for listed 14-, 15-, and 16-inch wheels with half-inch studs | Lippert: 20-25, 50-60, and 90-120 ft-lb; values vary by maker and wheel configuration. | ccd-0011131, page 9 |
| Wheel installation | Lug-nut torque recheck distances | Lippert: 10, 25, and 50 miles (16, 40, and 80 km); intervals vary by maker. | ccd-0011131, page 8 |
| Manual adjustment | Burnished-brake lining-to-drum clearance | Dexter detailed procedure: 0.010 inch; values vary by maker. | 9-15k complete service manual, page 51 |
| Manual adjustment | Brake application pressure | Dexter procedure: 80–90 psi; values vary by maker. | 9-15k complete service manual, page 51 |
| Chamber safety | Pressure-related failure warning | Dexter warns that pressure above 130 psi can cause air-chamber or spring-brake-chamber failure; not a test-pressure target, and values vary by maker. | 9-15k complete service manual, page 51 |
| Pushrod stroke | Chamber types 9, 12 and 16 | Dexter chart maximum: 1 1/2 inches; values vary by maker and application. | 9-15k complete service manual, page 52 |
| Pushrod stroke | Chamber types 20 and 24 | Dexter chart maximum: 1 3/4 inches; values vary by maker and application. | 9-15k complete service manual, page 52 |
| Pushrod stroke | Chamber type 30 | Dexter chart maximum: 2 inches; values vary by maker and application. | 9-15k complete service manual, page 52 |
| Applied contact | Feeler-gauge check | Dexter specifies that a 0.010-inch gauge should not fit between lining and drum during application; values vary by maker. | 9-15k complete service manual, page 52 |
| Linkage geometry | Applied pushrod-to-slack-adjuster angle | Dexter: approximately 90 degrees ±5 degrees; values vary by maker. | 9-15k complete service manual, page 52 |
| Automatic-adjuster setup | Pivot-pin diameter | Dexter alternative setup: 1/2 inch; values vary by maker. | 9-15k complete service manual, page 50 |
| Automatic-adjuster setup | Additional adjustment after drum stops | Dexter alternative setup: 1/4–1/2 wrench turn; values vary by maker. | 9-15k complete service manual, page 50 |
| Heavy-duty alignment | Lateral centerline offset E | Dexter: 1/4 inch or less for each axle; values vary by maker. | 9-15k complete service manual, page 72 |
| Heavy-duty alignment | Thrust A/B linear agreement | Dexter: within 1/8 inch; applies to the heavy-duty procedure, and values vary by maker. | 9-15k complete service manual, page 72 |
| Heavy-duty alignment | Thrust angular agreement | Dexter: within 0.1 degree; values vary by maker. | 9-15k complete service manual, page 72 |
| Heavy-duty alignment | Scrub C/D agreement | Dexter: within 1/16 inch, with the difference as close to zero as possible; values vary by maker. | 9-15k complete service manual, page 72 |
| Alignment retention | Heavy-duty track-rod clamp nut | Dexter: 150 ft-lb for the identified 5/8-11 UNC nut with clean, dry threads; values vary by maker. | 9-15k complete service manual, pages 72 and 74 |
| Alignment retention | Leaf-spring axle alignment follow-up | Dexter: check after 2,000–3,000 miles; intervals vary by maker. | 9-15k complete service manual, page 74 |
| Alignment retention | Heavy-duty bolt and nut torque follow-up | Dexter: after initial break-in, up to 1,000 miles, and at least every 4 months afterward; intervals vary by maker. | 9-15k complete service manual, page 74 |
| General axle installation | Kingpin-to-axle-end measurement difference | Dexter: no more than 1/16 inch in the general installation procedure; values vary by maker. | 9-15k complete service manual, page 65 |
| General axle installation | Interaxle measurement difference | Dexter: no more than 1/8 inch in the general installation procedure; values vary by maker. | 9-15k complete service manual, page 65 |
| Suspension inspection | Visual inspection of suspension components | Dexter: at least every 6,000 miles; intervals vary by maker. | LDServiceOnline, page 66 |
| U-bolt torque | Lippert 2K axle | 35 ft-lb; values vary by maker and configuration | ccd-0011257, page 3 |
| U-bolt torque | Lippert 3.5K axle with 1/2-inch U-bolt | 50 ft-lb; values vary by maker and configuration | ccd-0011257, page 3 |
| U-bolt torque | Lippert 5.2K axle | 65 ft-lb; values vary by maker and configuration | ccd-0011257, page 3 |
| U-bolt torque | Lippert 6K–8K axle, general chart entry | 90 ft-lb; values vary by maker and configuration | ccd-0011257, page 3 |
| U-bolt torque | Lippert 7K–8K axle with overslung springs and silver zinc U-bolts | 145 ft-lb; values vary by maker and configuration | ccd-0011257, page 3 |
| U-bolt torque | Lippert 10K axle | 95 ft-lb; values vary by maker and configuration | ccd-0011257, page 3 |
| U-bolt torque | Lippert 12K–16K axle | 115 ft-lb; values vary by maker and configuration | ccd-0011257, page 3 |
| Equalizer and shackle fastening | Lippert illustrated equalizer and shackle nuts | 30–50 ft-lb, bottomed against bolt shoulders; values vary by maker and design | ccd-0011275, page 4 |
| Equalizer installation check | Lippert illustrated shackle-link positions after lowering | Upright at approximately 10 o'clock and 2 o'clock; requirements vary by maker and design | ccd-0011275, page 4 |
| Torsion suspension inspection | Bostail torsion system inspection interval | Annually or every 36,000 miles, whichever comes first; intervals vary by maker | Bostail 8K Axle Manual, page 55 |
| Battery storage | Bostail breakaway-battery charging interval | At least every 90 days during storage; intervals vary by maker. | Bostail 8K Axle Manual, page 61 |
| E/H battery | Dexter illustrated installation minimum battery capacity | 9 Ah; values vary by maker and application. | LDServiceOnline, page 29 |
| E/H supply | Dexter illustrated tow-vehicle supply circuit | 12 V, 40 A; values vary by maker and application. | LDServiceOnline, page 29 |
| E/H supply check | Dexter black-to-white voltage with ignition on and brakes not applied | 12–13 V; values vary by maker and application. | LDServiceOnline, page 30 |
| E/H breakaway test | Dexter maximum switch-pulled duration during any test step | 2 minutes; limits vary by maker and procedure. | LDServiceOnline, page 31 |
| E/H breakaway test | Dexter white-to-yellow check after fully charging a battery when the actuator does not run | Check for at least 12 V; below 12 V indicates switch or wiring fault, above 12 V directs actuator replacement in this guide, and exactly 12 V has no explicit final disposition; thresholds vary by maker. | LDServiceOnline, page 31 |
| E/H wiring | Dexter black and white supply wires with actuator less than 10 feet from tow vehicle | 12 gauge recommended; values vary by maker and application. | LDServiceOnline, page 30 |
| E/H wiring | Dexter black and white supply wires with actuator more than 10 feet from tow vehicle | 10 gauge recommended; values vary by maker and application. | LDServiceOnline, page 30 |
| E/H wiring | Dexter other wires in the described E/H installation | 16 gauge minimum; values vary by maker and application. | LDServiceOnline, page 30 |
| Electric-brake measurement | Dexter chart current per magnet for a 12 by 2 inch brake | 3.0 A; values vary by maker and brake application. | LDServiceOnline, page 22 |
| Controller modulation | Dexter initial pedal-application voltage reference | Approximately 2 V, increasing progressively toward 12 V; values vary by maker. | LDServiceOnline, page 8 |
| Synchronization preparation | Dexter burnishing reference | 20–30 applications with approximately 20 mph speed reduction, allowing cooling between applications; values vary by maker. | LDServiceOnline, page 12 |
| Brake wiring | Bostail six-brake hookup at 30–50 ft hitch-to-axle distance | 8 AWG minimum copper; values vary by maker. | Bostail 8K Axle Manual, page 19 |
| Electrical diagnosis | Bostail controller-to-magnet voltage comparison | 12 V at controller output should provide at least 10.5 V at each magnet; values vary by maker. | Bostail 8K Axle Manual, page 47 |
| Electric-hydraulic diagnosis | Dexter ignition-on supply check | 12–13 V between documented black and white wires with brakes unapplied; values and wiring vary by maker. | LDServiceOnline, page 30 |
| Electric-hydraulic diagnosis | Dexter breakaway-test time limit | Switch pulled for no more than 2 minutes during any test step; values vary by maker. | LDServiceOnline, page 31 |
| Surge mounting | Dexter bolt-on actuator fasteners | 1/2 × 4 in Grade 5 bolts, tightened with locking nuts to 80 ft-lb; values vary by maker. | 2024.02LIT75000LightDutyActuatorInstallation, page 5 |
| Surge mounting | Dexter reinforcement and attachment requirements | Spacer tubes for tongues under 3/16 in thick; attachment hardware rated at least 150% of trailer GVWR; values vary by maker. | 2024.02LIT75000LightDutyActuatorInstallation, page 5 |
| Surge hydraulic service | Dexter fluid specification | Fresh DOT 3 from a fresh container; fluid requirements vary by maker. | 2024.02LIT75000LightDutyActuatorInstallation, page 6 |
| Surge hydraulic service | Dexter pressure-bleeder limit | 18 psi maximum; values vary by maker. | 2024.02LIT75000LightDutyActuatorInstallation, page 6 |
| Surge hydraulic service | Dexter minimum reservoir level during manual bleeding | At least half full; values vary by maker. | 2024.02LIT75000LightDutyActuatorInstallation, page 7 |
| Surge validation | Dexter low-profile slider-pin travel limits | Single axle: no more than 1/2 slot; tandem axles: no more than 3/4 slot during the prescribed forward-stop check; values vary by maker. | 2024.02LIT75000LightDutyActuatorInstallation, page 9 |
| Hitch weight guidance | Conventional bumper-type hitch | Dexter: 10% to 14% of gross vehicle weight; guidance varies by maker. | applications-manual-(lit-008-00), page 7 |
| Hitch weight guidance | Fifth wheel or gooseneck hitch | Dexter: 15% to 20% of gross vehicle weight; guidance varies by maker. | applications-manual-(lit-008-00), page 7 |
| Ball compatibility | Illustrated automatic-latching coupler | Demco: 2-5/16-inch ball; requirements vary by maker and model. | Demco-Coupler-Manual-1, page 8 |
| Inspection interval | Hardware recheck | Demco: every 100 hours or 50 miles; intervals vary by maker. | Demco-Coupler-Manual-1, page 5 |
| General bolt chart | 5/8-inch Grade 5 standard bolt | Demco: 150 lb-ft with non-greased, non-oiled threads and heads unless otherwise specified; values vary by maker and application. | Demco-Coupler-Manual-1, page 7 |
| General bolt chart | Locking-element adjustment | Demco: increase chart torque by 5% when locking elements are used; instructions vary by maker. | Demco-Coupler-Manual-1, page 7 |
| Gooseneck capacity | Model 25050 gross trailer weight | CURT: 30,000 lb; never override the towing vehicle's capacity, and values vary by maker and model. | Curt-Spec-Sheet, page 1 |
| Gooseneck capacity | Model 25050 tongue weight | CURT: 7,500 lb; values vary by maker and model. | Curt-Spec-Sheet, page 1 |
| Gooseneck clearance | Model 25050 clear area during towing | CURT: at least 6 inches around the coupler free of obstructions and loose objects; values vary by maker and model. | Curt-Spec-Sheet, page 1 |
| Gooseneck mounting torque | Model 25050 1-inch hardware | CURT: 400 ft-lb; values vary by maker and application. | Curt-Spec-Sheet, page 2 |
| Gooseneck mounting torque | Model 25050 3/4-inch hardware | CURT: 300 ft-lb; values vary by maker and application. | Curt-Spec-Sheet, page 2 |
| Gooseneck maintenance | Model 25050 pivot-point oil and service interval | CURT: SAE 30 wt. motor oil at pivot points, with the listed maintenance performed at least annually; lubricants and intervals vary by maker. | Curt-Spec-Sheet, page 1 |
| Electrical wiring | Four brakes, 30–50-foot hitch-to-axle distance | Bostail: minimum 10 AWG copper hookup wire; values vary by maker. | Bostail 8K Axle Manual, p. 19 |
| Electrical wiring | Six brakes, 30–50-foot hitch-to-axle distance | Bostail: minimum 8 AWG copper hookup wire; values vary by maker. | Bostail 8K Axle Manual, p. 19 |
| Electrical diagnosis | Magnet voltage with 12 volts at controller | Bostail: minimum 10.5 volts at each magnet; values vary by maker. | Bostail 8K Axle Manual, p. 47 |
| Electrical diagnosis | 12 × 2-inch brake nominal magnet current | Bostail: 3.0 amperes per magnet at 12 volts with warm magnets, maximum gain, and system resistor at zero; values vary by maker. | Bostail 8K Axle Manual, p. 47 |
| Lining inspection | Thickness replacement threshold | Bostail: replace when lining is less than 1/16 inch thick; values vary by maker. | Bostail 8K Axle Manual, p. 39 |
| Shoe assembly | Covered shoe-kit anchor-post locknut | Dexter: 200 in.-lbs.; values vary by maker and assembly. | 05965300BrakeShoeInstructionSheet, pp. 3–4 |
| Brake adjustment | Initial and subsequent clearance adjustment | Bostail: first 200 miles, then every 3,000 miles or as use and performance require; intervals vary by maker. | Bostail 8K Axle Manual, p. 42 |
| Standard break-in | Trailer-brake application voltage | Lippert: approximately 8–10 volts through the controller slide; values vary by maker. | Electric-Drum-Brake-Break-In-Period, p. 1 |
| Standard break-in | Speed reduction | Lippert: 40 mph to 20 or 25 mph, observing posted limits; values vary by maker. | Electric-Drum-Brake-Break-In-Period, p. 1 |
| Standard break-in | Application range and spacing | Lippert: 20–50 applications at one-mile intervals; values vary by maker. | Electric-Drum-Brake-Break-In-Period, p. 1 |
| Separate skilled-technician break-in | Aggressive-method speed and application distance | Lippert: 60–70 mph within posted limits, with trailer brakes applied for one-half mile while maintaining speed without lockup under favorable conditions; values vary by maker. | Electric-Drum-Brake-Break-In-Period, p. 2 |
| Capacity-chart assumptions | Bostail minimum rear-hinge-pivot-to-floor vertical height | 3 inches; values vary by maker | Bostail Power Hoist Capacity Chart |
| Capacity-chart assumptions | Bostail hydraulic relief-pressure basis | 3,200 psi; chart assumption, not an adjustment instruction; values vary by maker | Bostail Power Hoist Capacity Chart |
| Capacity example | Bostail PH310 with 8-foot body, 18-inch overhang and 45-degree dump angle | 4.4 tons under chart assumptions; values vary by maker | Bostail Power Hoist Capacity Chart |
| Relief protection | KTI illustrated power-up, power-down primary relief | 3,200 psi, factory preset; values vary by maker | Hydraulics-Troubleshooting-Manual 2019 |
| Relief protection | KTI illustrated power-up, power-down secondary relief | 1,500 psi, factory preset; values vary by maker | Hydraulics-Troubleshooting-Manual 2019 |
| Pilot operation | KTI illustrated lowering-valve pilot ratio | 2.5:1; values vary by maker | Hydraulics-Troubleshooting-Manual 2019 |
| Valve installation | KTI directional-valve maximum torque in the troubleshooting section | 18 ft-lb maximum; values vary by maker | Hydraulics-Troubleshooting-Manual 2019 |
| Cable selection | KTI cable table: 100–150 amps at less than 5 feet | 4 Gauge; values vary by maker | Hydraulics-Troubleshooting-Manual 2019 |
| Cable selection | KTI cable table: 100–150 amps at 5–10 feet | 2 Gauge; values vary by maker | Hydraulics-Troubleshooting-Manual 2019 |
| Electrical diagnosis | KTI possible start-solenoid voltage during a no-extension complaint | Below 9.5 volts while attempting operation; diagnostic observation, not a universal acceptance limit; values vary by maker | Hydraulics-Troubleshooting-Manual 2019 |
| Hookup wiring | Bostail minimum copper wire: four brakes, under 30 ft | 12 AWG; values vary by maker | Bostail 8K Axle Manual, page 19 |
| Hookup wiring | Bostail minimum copper wire: four brakes, 30–50 ft | 10 AWG; values vary by maker | Bostail 8K Axle Manual, page 19 |
| Hookup wiring | Bostail minimum copper wire: six brakes, 30–50 ft | 8 AWG; values vary by maker | Bostail 8K Axle Manual, page 19 |
| Controller voltage | Dexter initial brake-pedal application guidance | Approximately 2 V; values vary by maker | LDServiceOnline, page 8 |
| Magnet voltage | Bostail minimum magnet voltage with 12 V controller output | 10.5 V; values vary by maker | Bostail 8K Axle Manual, page 47 |
| Magnet current | Bostail 12 x 2 inch brake, individual magnet at nominal chart conditions | 3.0 A at 12 V, normal operating temperature, resistor at zero, maximum gain; values vary by maker | Bostail 8K Axle Manual, page 47 |
| System current | Bostail four 12 x 2 inch brakes at nominal chart conditions | 12.0 A at 12 V, normal operating temperature, resistor at zero, maximum gain; values vary by maker | Bostail 8K Axle Manual, page 47 |
| Magnet resistance | Bostail 12 x 2 inch brake magnet chart value | 3.2 ohms; values vary by maker | Bostail 8K Axle Manual, page 47 |
| Electrohydraulic supply | Dexter E/H black-to-white voltage, ignition on and brakes released | 12–13 V; values vary by maker | LDServiceOnline, page 30 |
| Breakaway testing | Dexter E/H maximum switch-pulled duration during each test step | 2 minutes; limits vary by maker | LDServiceOnline, page 31 |
| Hydraulic pressure | Covered disc-brake maximum operating pressure | Dexter: 1,600 psi; values vary by maker and application. | LDServiceOnline, page 24 |
| Actuator power | Tow-vehicle supply shown in actuator schematic | Dexter: +12 V, 40 A circuit; values vary by maker. | LDServiceOnline, page 29 |
| Breakaway power | Battery capacity shown in actuator schematic | Dexter: minimum 9 Ah; values vary by maker. | LDServiceOnline, page 29 |
| Actuator wiring | Black and white wires by actuator distance from tow vehicle | Dexter: under 10 ft, 12 gauge; over 10 ft, 10 gauge; other wires minimum 16 gauge. Exactly 10 ft is not assigned in the supplied text; values vary by maker. | LDServiceOnline, page 30 |
| Electrical diagnosis | Black-to-white voltage with ignition on and brakes released | Dexter: 12–13 V; values vary by maker. | LDServiceOnline, page 30 |
| Breakaway diagnosis | Maximum pulled-switch duration during each outlined test step | Dexter: 2 minutes; values vary by maker. | LDServiceOnline, page 31 |
| Rotor service | Minimum thickness for covered rotor applications | Dexter: 6K/7K/8K rotors, 1.03 in; 3.5K rotor, 0.85 in. Values vary by maker and application. | LDServiceOnline, page 51 |
| Floating-caliper installation | Covered 3.5K caliper mounting bolts | Dexter: 40–50 ft-lb; values vary by maker and application. | LDServiceOnline, page 35 |
| Fixed-caliper installation | Covered caliper mounting bolts | Dexter: 25–35 ft-lb; values vary by maker and application. | LDServiceOnline, page 44 |
| Hydraulic fittings | Covered fixed-caliper crossover line and bleeder/adapter | Dexter: crossover line 12–15 ft-lb; bleeder screw and hydraulic fitting adapter 60–76 in-lb. Values vary by maker and application. | LDServiceOnline, pages 44–45 |
| Clip-on pad installation | Slider-bolt locknuts in the supplied clip-on pad instruction | Dexter: 15–30 ft-lb; values vary by maker and document revision. | 1016KDiscBrake, page 2 |
| Disc-pad maintenance | Visual pad inspection interval in the covered axle manual | Lippert: 36,000 miles or 12 months, whichever comes first; values vary by maker. | Lippert-Axle-8K-16K-Manual, page 9 |
| Electric diagnosis | Dexter voltage during slow controller-bar actuation | 0 V rising gradually to about 12 V; values vary by maker and controller application. | 9-15k complete service manual, page 22 |
| Electric diagnosis | Dexter listed four-brake current | 12.0 A for the brake sizes in the chart; values vary by maker and brake application. | 9-15k complete service manual, page 23 |
| Friction inspection | Dexter lining replacement threshold | 1/16 inch or less; values vary by maker. | 9-15k complete service manual, page 18 |
| Hydraulic actuation | Dexter breakaway-test switch duration | No more than 2 minutes during any test step; limits vary by maker. | 9-15k complete service manual, page 36 |
| Air brakes | Dexter listed type 30 chamber maximum stroke | 2 inches; limits vary by maker and chamber application. | 9-15k complete service manual, page 52 |
| Bearings | Dexter covered double-nut wheel-end allowable end play | 0.001-0.010 inch; values vary by maker and bearing design. | 9-15k complete service manual, page 64 |
| Alignment | Dexter heavy-duty suspension rear spacing agreement | Measurements C and D equal within 1/16 inch; values vary by maker and alignment procedure. | 9-15k complete service manual, page 72 |
| Wheel attachment | Dexter page 77 post-installation wheel torque checks | After the first 50 miles and again at 100 miles, then periodically; schedules vary by maker and application. | 9-15k complete service manual, page 77 |
| Storage | Lippert breakaway battery charging | At least every 90 days during storage; schedules vary by maker. | Lippert-Axle-8K-16K-Manual, page 27 |
| Bearing inspection | Lippert physical bearing-inspection interval | Every 36,000 miles or 12 months, whichever comes first; intervals vary by maker. | ccd-0011255 |
| Bearing grease | Lippert minimum dropping point | 446°F (230°C); grease specifications vary by maker. | ccd-0011255 |
| Bearing grease | Lippert grease consistency | NLGI No. 2; grease specifications vary by maker. | ccd-0011255 |
| Bearing grease | Lippert minimum viscosity index | 80; grease specifications vary by maker. | ccd-0011255 |
| Bearing adjustment | Lippert conventional idler-hub initial spindle-nut torque | 50 ft-lb while rotating the hub, followed by torque release and finger-tight adjustment; values vary by maker and design. | ccd-0011133 |
| Wheel installation | Lippert first-stage torque: 14-inch wheel, 1/2-inch studs | 20–25 ft-lb; values vary by maker and wheel/fastener configuration. | ccd-0011133 |
| Wheel installation | Lippert second-stage torque: 14-inch wheel, 1/2-inch studs | 50–60 ft-lb; values vary by maker and wheel/fastener configuration. | ccd-0011133 |
| Wheel installation | Lippert final-stage torque: 14-inch wheel, 1/2-inch studs | 90–120 ft-lb; values vary by maker and wheel/fastener configuration. | ccd-0011133 |
| Wheel installation | Lippert post-installation lug-nut checks | Check and re-torque after 10, 25 and 50 miles; intervals vary by maker. | ccd-0011133 |
| Hydraulic pressure | Primary relief in the documented circuit examples | KTI: 3200 psi, factory preset; values vary by maker. | Hydraulics-Troubleshooting-Manual 2019, pages 6 and 9 |
| Hydraulic pressure | Secondary relief in the documented double-acting circuit | KTI: 1500 psi; values vary by maker. | Hydraulics-Troubleshooting-Manual 2019, page 10 |
| Valve operation | Documented lowering-valve pilot ratio | KTI: 2.5:1; values vary by maker. | Hydraulics-Troubleshooting-Manual 2019, page 9 |
| Valve installation | Maximum torque for the directional valve discussed in the guide | KTI: 18 ft-lb maximum; values vary by maker. | Hydraulics-Troubleshooting-Manual 2019, page 18 |
| Electrical diagnosis | Possible starter-solenoid voltage during failure to extend | KTI notes a reading below 9.5 V may occur; this is a diagnostic observation, not a universal minimum, and values vary by maker. | Hydraulics-Troubleshooting-Manual 2019, page 21 |
| Remote power | Receiver supply range | KTI documented remotes: 9–30 V DC; values vary by maker. | KTI-Remote-Kit-Instructions, pages 1-2 |
| Remote outputs | Sourcing-output and system current ratings | KTI documented remotes: 5 A per output and 20 A system maximum; values vary by maker. | KTI-Remote-Kit-Instructions, pages 1-2 |
| Remote charging | Maximum Micro USB insertion force | KTI: do not exceed 5 lb; values vary by maker. | KTI-Remote-Kit-Instructions, pages 1-2 |
| Remote operation | Idle automatic shutdown | KTI documented transmitters: 15 minutes without button presses; values vary by maker. | KTI-Remote-Kit-Instructions, pages 1-2 |
| Remote synchronization | POWER hold to enter synchronization | KTI documented transmitters: more than 10 seconds, starting with transmitter off; values vary by maker. | KTI-Remote-Kit-Instructions, pages 1-2 |
| Remote programming | Function-pair hold for programming entry | KTI programmable remote: 5 seconds; values vary by maker. | KTI-Remote-Kit-Instructions, page 2 |
| Remote programming | Receiver acceptance indication | KTI programmable remote: steady green LED for 3 seconds; values vary by maker. | KTI-Remote-Kit-Instructions, page 2 |
| Wheel torque | Diamond C: 15-inch steel wheel, 1/2-inch stud, coned nut | 90-120 ft-lb; values vary by maker | Lug-Nut-Torque-Specs 2023, page 1 |
| Wheel torque | Diamond C: 15-inch aluminum wheel, 1/2-inch stud, coned nut | 90-100 ft-lb; values vary by maker | Lug-Nut-Torque-Specs 2023, page 1 |
| Wheel torque | Diamond C: 16-inch aluminum wheel, 5/8-inch stud, rotating-flange nut | 150 ft-lb; values vary by maker | Lug-Nut-Torque-Specs 2023, page 1 |
| Wheel torque | Diamond C: listed steel 17.5-inch single or 16-inch dual wheels, 5/8-inch stud, non-rotating flanged nut | 275-325 ft-lb; values vary by maker | Lug-Nut-Torque-Specs 2023, page 1 |
| Torque recheck | Diamond C: initial towing checks | Before first tow and again after about 50 miles; intervals vary by maker | Lug-Nut-Torque-Specs 2023, page 1 |
| Staged wheel torque | Lippert: listed 15-inch wheel with 1/2-inch studs, first stage | 20-25 ft-lb; values vary by maker | ccd-0011134, page 9 |
| Staged wheel torque | Lippert: listed 15-inch wheel with 1/2-inch studs, second stage | 50-60 ft-lb; values vary by maker | ccd-0011134, page 9 |
| Staged wheel torque | Lippert: listed 15-inch wheel with 1/2-inch studs, final stage | 90-120 ft-lb; values vary by maker | ccd-0011134, page 9 |
| Torque recheck | Lippert: post-installation mileage checks | 10, 25, and 50 miles; intervals vary by maker | ccd-0011134, page 8 |
| Tire maintenance | Bostail: tire-pressure check interval | Weekly; intervals vary by maker | Bostail 8K Axle Manual, page 58 |
| Load distribution | Conventional bumper-type hitch load | Dexter recommendation: 10%–14% of gross vehicle weight; values vary by maker. | applications-manual-(lit-008-00) |
| Load distribution | Fifth-wheel and gooseneck hitch load | Dexter recommendation: 15%–20% of gross vehicle weight; values vary by maker. | applications-manual-(lit-008-00) |
| Clearance | Tire-to-tire clearance | Dexter application guidance: at least 1 inch under any loading condition; values vary by maker and installation. | applications-manual-(lit-008-00) |
| Clearance | Fender clearance | Dexter application guidance: 3 inches above the tire at full load; values vary by maker and installation. | applications-manual-(lit-008-00) |
| Alignment | Axle perpendicularity to the trailer centerline | Dexter application guidance: within ±0.5 degree; values vary by maker and application. | applications-manual-(lit-008-00) |
| Alignment | Multiple-axle parallelism | Dexter application guidance: within 1/16 inch measured at wheel centers; values vary by maker and application. | applications-manual-(lit-008-00) |
| Bearing maintenance | Grease-bearing lubrication interval | Dexter grease-bearing section: every 12 months or 12,000 miles; values vary by maker and bearing arrangement. | LDServiceOnline |
| Wheel fasteners | Post-installation torque checks | Dexter schedule: check and retorque after the first 10, 25 and 50 miles, then check periodically; values vary by maker. | LDServiceOnline |
| Brake hookup wiring | Dexter: two brakes; chart gives no distance condition | Minimum 12 AWG copper; values vary by maker | LDServiceOnline, page 12 |
| Brake hookup wiring | Dexter: four brakes, hitch-to-axle distance under 30 ft | Minimum 12 AWG copper; values vary by maker | LDServiceOnline, page 12 |
| Brake hookup wiring | Dexter: four brakes, hitch-to-axle distance 30–50 ft | Minimum 10 AWG copper; values vary by maker | LDServiceOnline, page 12 |
| Brake hookup wiring | Dexter: six brakes, hitch-to-axle distance under 30 ft | Minimum 10 AWG copper; values vary by maker | LDServiceOnline, page 12 |
| Brake hookup wiring | Dexter: six brakes, hitch-to-axle distance 30–50 ft | Minimum 8 AWG copper; values vary by maker | LDServiceOnline, page 12 |
| Voltage testing | Dexter: voltage during slow controller-bar actuation | Gradual increase from 0 V to about 12 V; values vary by maker | LDServiceOnline, page 21 |
| Current reference | Dexter: individual magnet for a 12 x 2-inch brake | 3.0 A per magnet; values vary by maker | LDServiceOnline, page 22 |
| Current reference | Dexter: four 12 x 2-inch brakes | 12.0 A total; values vary by maker | LDServiceOnline, page 22 |
| Breakaway battery storage | Lippert: charging interval during extended storage | At least every 90 days; values vary by maker | Lippert-Axle-Manual, page 41 |
| ABS electrical service | Lippert: power-cycle waiting interval after all power is disconnected | 10 seconds before reconnecting; values vary by maker | Lippert-Anti-Lock-Braking-System, page 3 |
| Hydraulics | KTI revised bleed-cycle relief overrun | 5–10 seconds; only for equipment confirmed to use this procedure | Revised-Bleed-Cycle.pdf, page 1 |
| Hydraulics | KTI revised bleed-cycle reservoir minimum | Half full during operation | Revised-Bleed-Cycle.pdf, page 1 |
| Hydraulics | KTI aerated-fluid pause | 10 minutes or until fluid appears normal | Revised-Bleed-Cycle.pdf, page 1 |
| Hydraulics | KTI listed cold-temperature fluid selection | −20°F to +32°F: ISO 15 | Single-Acting-Installation-Instructions-INST0001.pdf, page 2 |
| Hydraulics | KTI listed warmer-temperature fluid selection | +14°F to +120°F: ISO 22, ISO 32 or ATF Dexron III | Single-Acting-Installation-Instructions-INST0001.pdf, page 2 |
| Hydraulics | KTI LSV2-08-4CO and LSPC-080-4-00 cartridge torque | 18 ft-lb maximum; lubricate rings with approved hydraulic fluid | Valve-Installation.pdf, page 2 |
| Hydraulics | KTI 395-CK001 jacket removal / conductor strip | 1-1/2 inches / 3/8 inch | How-to-disassemble-Quick-Disconnect.pdf, page 1 |
| Hydraulics | KTI specified SAE #6 / 9/16-18 ORB fitting torque | 18 ft-lb; only the fittings identified in this installation | Double-Acting-Installation-Instructions-.pdf, page 1 |
| Hydraulics | KTI specified upper battery-connection nut | 3 ft-lb while holding lower nut; not a universal terminal torque | Double-Acting-Installation-Instructions-.pdf, page 1 |
| Axles | Lippert beam-replacement backing-plate nuts: 2K–7K | 35–55 ft-lb | ccd-0001660.pdf, page 6 |
| Axles | Lippert beam-replacement backing-plate nuts: 8K–16K | 55–80 ft-lb | ccd-0001660.pdf, page 6 |
| Brakes | Lippert M-006 intensive-use brake-service cadence | 3,000–6,000-mile increments; abnormal operation requires immediate service | ccd-0002421.pdf, page 2 |
| Brakes | Lippert M-006 lining boundary | Replace below 1/16 inch; older 8K–16K manual uses 1/16 inch or less—verify applicability | ccd-0002421.pdf, page 3 |
| Battery warranty | Continental marine deep-cycle 12 V / marine AGM periods | 12 months / 18 months; historical policy, verify current terms | CBS_Battery_Warranty_2024_MAR_1_.pdf, page 2 |
| Battery warranty | Continental SLA / SLA Heavy Duty periods | 6 months / 12 months; historical policy, verify current terms | CBS_Battery_Warranty_2024_MAR_1_.pdf, page 2 |
| Battery warranty | Continental commercial-use adjustment | Half the applicable period in the Continental policy; do not generalize to partner brands | CBS_Battery_Warranty_2024_MAR_1_.pdf, page 2 |
Confirm the specification against the exact component, model, and current manufacturer instructions before service.
BEFORE YOU GET STARTED
Straight answers.
Can I train on my own, without a shop?+−
Yes. Choose individual training when you create your account. You can also join a shop later without starting your learning record again.
Do technicians keep their certificates if they leave a shop?+−
Certificates are issued to the technician’s account, not the employer. Each has a public verification link and a one-year expiry date.
Do I need special equipment or an installation?+−
No installation is needed. Lessons, assessments, and virtual circuit practice run in a web browser on a phone, tablet, or computer. Virtual practice does not replace supervised work on real equipment.
Is this a NATDA or ASE certification?+−
No. TrailerPro Academy issues its own training certificates and is not affiliated with or accredited by NATDA or ASE. It can complement industry workshops and external certification preparation, but does not replace their requirements.
What does a paid plan include?+−
Lessons are free to read. Tech Pro and shop plans unlock module quizzes, level finals, certificates, every monthly CEU release, and the AI diagnostic assistant. Shop plans cover 5 or 15 technician seats. Cancel anytime — access continues to the end of the paid period and earned certificates stay valid.
Does passing an exam certify hands-on competence?+−
The current certificates verify written assessment results. Foreman practical sign-offs are planned but are not yet available. Follow manufacturer instructions and your shop’s supervision and safety requirements.
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