Operation & Lubrication
- Execute proper dump body lowering techniques to avoid load shocks.
- Implement the specified 6-month lubrication schedule for hoist and hinge points.
- Adhere to hydraulic fluid cleanliness standards by pre-filtering into the reservoir.
- Grease gun — Apply EP3 grease to hoist and hinge points every 6 months.
- Hydraulic fluid filter — Pre-filter hydraulic fluid before it enters the reservoir.
- Grease rags — Clean grease fittings before and after application of EP3 grease.
Never exceed gross capacity. Never jerk the body or drive and stop quickly to free a stuck load — lower it and free the load.
Grease hoist and hinge points with EP3 grease every 6 months.
Pre-filter hydraulic fluid into the reservoir. For pump electrical faults, see the Hydraulic Power Unit course.
How It Works
Load Shock Prevention
Never jerk the body or drive and stop quickly to free a stuck load. These actions cause mechanical shock; if a load is stuck, the body must be lowered and the load freed manually.
Capacity Limits
The hoist system is designed for specific mechanical loads. Never exceed the gross capacity of the unit, as this compromises the structural integrity and hydraulic safety of the hoist.
Hydraulic Cleanliness
Hydraulic systems are sensitive to contaminants. Always pre-filter hydraulic fluid into the reservoir to ensure debris does not enter the system, which could lead to pump or valve failure.
Diagnostic Chart
| Symptom | Check | Spec / Expected | Likely cause & fix |
|---|---|---|---|
| Stuck load in the dump body during operation. | Attempt to lower the body safely. | Lower it and free the load. | Attempting to free a stuck load by jerking the body or sudden stops. Basis: Premium Supply Scissor Hoist Manual |
| Pivot points exhibit excessive wear or noise. | Verify last date of lubrication and type of grease used. | EP3 grease every 6 months. | Failure to lubricate hoist and hinge points at the required semi-annual interval. Basis: Premium Supply Scissor Hoist Manual |
| Dump body exceeds weight limits. | Compare current load against the hoist rating. | Never exceed gross capacity. | Overloading the trailer beyond its rated structural and hydraulic capabilities. Basis: Premium Supply Scissor Hoist Manual |
| Pump electrical fault identified. | Transition to the specific electrical training module. | Per the applicable manual | Wiring, battery, or motor failure requiring HPU-specific diagnostics. Basis: Premium Supply Scissor Hoist Manual |
At the Bay: Diagnose the Case
CASE 1 / 4
Stuck load in the dump body during operation.
- Test
- Compare
- Correct
Select the next check
Basis: Premium Supply Scissor Hoist Manual. A likely cause is a hypothesis; confirm it with the applicable service procedure before repair.
Common Bay Mistakes
- ✕ Driving and stopping quickly to dislodge a stuck load.
- ✕ Jerking the hoist body to assist in dumping.
- ✕ Exceeding the gross capacity of the hoist system.
- ✕ Pouring hydraulic fluid directly into the reservoir without pre-filtering.
- ✕ Neglecting hinge point lubrication for more than 6 months.
Quick Check
Practice only — not scored.
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: Premium Supply Scissor Hoist Manual — 6, 13