KTI Bleed-Cycle Selection and Air Removal
- Select the bleeding procedure confirmed for the installed KTI equipment.
- Remove air while controlling fluid level, aeration and relief-overrun duration.
- Prepare the trailer safely before opening hydraulic components.
- Flashlight — Read unit identification and inspect reservoir fluid and accessible connections.
- Combination wrenches — Address loose connections only after the equipment is safely supported, cooled, depressurized and isolated.
- Timer — Monitor the documented relief-overrun duration and aerated-fluid pause.
- Clean funnel — Add fluid specified by the applicable equipment instructions without introducing contamination.
- Battery charger — Recharge the battery after bleeding using a charger appropriate to the installed battery.
- Wheel chocks — Help immobilize the trailer before movement testing or service.
Air in a hydraulic system can produce erratic movement, foaming and reservoir overflow. Before bleeding, identify the power unit, cylinder arrangement and installation instructions. The supplied Revised-Bleed-Cycle sheet is undated; its filename alone does not establish that it supersedes every older installation guide.
For equipment confirmed to use Revised-Bleed-Cycle.pdf, page 1, remove the breather cap to observe the fluid and verify tight fluid connections. Maintain at least half the reservoir volume during operation. Extend the cylinder fully, then continue running over the existing relief for 5–10 seconds; recheck the fluid and retract. Repeat until operation is smooth. This limited-duration source instruction is not permission to change the relief setting or continuously stall a pump.
For a double-acting cylinder, that sheet calls for the same process in both power-up and power-down. If fluid becomes aerated or foams, stop and wait 10 minutes or until it appears normal before continuing. Recharge the battery after the cycle because it consumes considerable energy.
The older Double-Acting-Installation-Instructions-.pdf, page 5, instead describes one-third extension and return, two-thirds extension and return, then full extension and return, with pauses when aeration appears. Single-Double-Acting-Installation.pdf, page 6, describes the same staged approach. Keep these procedures separate; ask KTI which applies if equipment documentation conflicts.
Before disconnecting a hose or removing a valve, the revised sheet requires the bed fully lowered or secured on a safety prop. Mechanical support does not release trapped pressure: cool and depressurize the system, immobilize the trailer and isolate controls before opening it. Valve-Installation.pdf, page 1, prohibits work on a hot or pressurized system and directs pendant disconnection.
How It Works
Procedure applicability comes before bleeding
Identify the power unit, cylinder arrangement and installation instructions before selecting a cycle; the undated Revised-Bleed-Cycle.pdf filename does not establish universal supersession. Double-Acting-Installation-Instructions-.pdf and Single-Double-Acting-Installation.pdf describe one-third extension and return, two-thirds extension and return, then full extension and return, with pauses for aeration. Keep that staged method separate from the revised relief-overrun method and ask KTI to resolve conflicting equipment documentation.
Air removal and controlled relief operation
Entrained air compresses under load, contributing to erratic movement, while aerated oil can foam and overflow the reservoir. For equipment confirmed to use the revised sheet, remove the breather cap, verify tight fluid connections, maintain at least half the reservoir volume, extend fully and run over the existing relief for only 5–10 seconds before rechecking fluid and retracting; double-acting equipment requires the same process in both power-up and power-down. Relief operation converts energy into heat, so this limited instruction never authorizes changing the relief setting or continuously stalling the pump.
Aeration recovery and safe access
If fluid aerates or foams, stop and wait 10 minutes or until fluid appears normal before continuing; repeat the applicable cycle until movement is smooth, restore the cap and recharge the battery. Before disconnecting a hose or removing a valve, fully lower the bed or secure it on its approved safety prop, immobilize the trailer and keep personnel clear. Mechanical support does not release trapped pressure: cool and depressurize the system, isolate controls and disconnect the pendant before opening it.
Step-by-Step Procedure
0/8 doneManual-specific service values — verify installed equipment
| Minimum reservoir level during bleeding | Half full |
| Revised cycle: time over relief at full extension | 5–10 seconds |
| Aerated-fluid pause | 10 minutes or until fluid appears normal |
Diagnostic Chart
| Symptom | Check | Spec / Expected | Likely cause & fix |
|---|---|---|---|
| The available instructions describe different bleed cycles. | Compare installed-unit identification, cylinder arrangement and supplied installation instructions; obtain KTI clarification if applicability remains uncertain. | Do not combine the staged-extension procedure with the revised relief-overrun procedure. | Different published procedures have been treated as interchangeable, or the revised filename has been mistaken for proof of supersession. Basis: Revised-Bleed-Cycle.pdf |
| Movement is erratic and the reservoir fluid foams or overflows. | Stop cycling, observe the fluid and check connection tightness safely before resuming the confirmed procedure. | Wait 10 minutes or until fluid appears normal before continuing. | Air in the hydraulic system can cause erratic movement, foaming and reservoir overflow. Basis: Revised-Bleed-Cycle.pdf |
| Reservoir level falls excessively during cylinder movement. | With the breather cap removed for the confirmed revised procedure, monitor fluid throughout travel and recheck after the documented relief-overrun step. | Maintain at least half the reservoir volume during operation. | Insufficient available reservoir fluid can allow air ingestion as cylinder movement changes the oil held outside the reservoir. Basis: Revised-Bleed-Cycle.pdf |
| A persistent leak is found at a connection. | With the system safely supported, cooled, depressurized and isolated, clean and inspect the connection for damaged sealing surfaces, deteriorated seals or misalignment; never search for a pressurized leak with a hand. | Use the applicable fitting and equipment service instructions; do not guess tightening requirements. | Seal damage or misalignment may prevent sealing even when the connection feels tight. Basis: General shop practice |
At the Bay: Diagnose the Case
CASE 1 / 4
The available instructions describe different bleed cycles.
- Test
- Compare
- Correct
Select the next check
Basis: Revised-Bleed-Cycle.pdf. A likely cause is a hypothesis; confirm it with the applicable service procedure before repair.
Common Bay Mistakes
- ✕ Assuming an undated revised filename overrides every installation guide.
- ✕ Blending staged extension with the relief-overrun cycle.
- ✕ Changing the relief setting or extending relief operation to force air out.
- ✕ Mistaking a safety prop for hydraulic depressurization.
Quick Check
Practice only — not scored.
Plan the Service Sequence
Planning practice only. Follow the applicable manufacturer's instructions, employer safety program and qualified supervision on real equipment.
Plan the first action. Compare the service steps with the bay mistakes.
Hands-on: Shop Test Equipment
Hydraulic Pressure & Relief Gauge
0–5,000 psi gauge on the pump pressure port, DC clamp meter, battery voltmeter
🛠 Equip your bay for this test →Symptom: Routine check before a customer pickup.
Spec limits used
- 3,200 psi — Primary relief (factory preset) (KTI Hydraulics Troubleshooting Manual 2019)
- 1,500 psi — Secondary relief, circuit 111 (KTI Hydraulics Troubleshooting Manual 2019)
- below 9 V — Low-voltage alarm (KTI remote)
- illustrative only — Motor current & voltage drop (General shop practice)
Simulated readings for practice. Always follow the manufacturer's procedure and values on a real trailer.
Source: Revised-Bleed-Cycle.pdf — 1