Test
The counterbalance valve allows the tailgate to open when the dump body is raised. The counterbalance valve also allows the tailgate to close when the dump body is lowered. The counterbalance valve also holds the tailgate closed when the dump body is lowered. If any of the above conditions are not true, the counterbalance valve is out of adjustment.
Note: If the dump body has no load, the tailgate may not open immediately when the dump body is raised.
Adjust
| NOTICE |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
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| Illustration 1 | g00634829 |
Location of the tailgate cylinder and the counterbalance valve | |
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| Illustration 2 | g00506087 |
The counterbalance valve is located on the tailgate cylinder. (1) Counterbalance valve | |
If there is visible leakage of the counterbalance valve, replace the seals with 7U-2303 Seal Kit .
Check for any physical problems that could prevent movement of the tailgate. There is no adjustment of the counterbalance valve. Replace 133-8810 Counterbalance Valve (1) and test for proper operation of the tailgate. See Disassembly and Assembly, "Tailgate Lock Valve - Remove".
If the operation of the tailgate is not correct, check the supply pressure. This can be done with the following procedure:
- Stop the engine.
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| Illustration 3 | g00634166 |
Location of the hoist control valve | |
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| Illustration 4 | g00506182 |
The raise port is located on the hoist control valve. The hoist control valve is located on the rear of the front frame. (1) Pressure port for the hoist system | |
- Attach a 25000 kPa (36000 psi) pressure gauge to the pressure port for the hoist system (2) .
- Make sure that there is adequate overhead clearance in order to fully raise the dump body. Start the engine and fully raise the dump body. Hold the hoist control in the raise position.
- Read the pressure at the pressure test port for the hoist system (2). The pressure should be at least 21000 kPa (3000 psi). If the pressure is not correct, check the body hoist system. See Testing and Adjusting, "Hoist System Troubleshooting".
- Fully lower the dump body and stop the engine. Remove the test equipment.