VALVE GP 8E7582 - Caterpillar

Performance Tests
The hydrostatic pump contains a charge pump. Oil from the charge pump provides signal oil and pilot oil. The charge oil also replenishes the oil for the hydrostatic drive system. The charge pump has a relief valve that is adjustable with a shim.Pressures that are too low will cause a decrease in a machine's performance. Pressures that are too high will cause a decrease in the life of hoses and components. Pressures that are too high can also cause performance problems.
The piston pump ( hydrostatic) makes noise. There are air bubbles in the oil.
The crossover relief valve opens at low oil pressure.
The output of the piston pump is low.
There is no pressure from the piston pump.
The machine moves with the direction control in the NEUTRAL position.
The machine will not start to move until the engine speed is very high.
The machine has low performance. The machine has weak force.
The machine's maximum speed is not set to the correct specification when the speed selector switch is in the FAST mode.
The machine's maximum speed does not change when the speed selector switch is moved from the SLOW mode to the FAST mode.Problem 1The piston pump ( hydrostatic) makes noise. There are air bubbles in the oil.Probable Cause
The hydraulic oil level could be low. Check the hydraulic oil level.
The viscosity of the hydraulic oil could be incorrect. Take an oil sample.Problem 2The crossover relief valve opens at low oil pressure.Probable Cause
The crossover relief valve may be improperly adjusted. Refer to the Testing