VALVE GP-MODULATING 1296303 - Caterpillar

Refer to the Specifications, System Operation, Testing and Adjusting manuals for the screed on your machine for additional information on the screed portion.The problem is a large amount of air in the oil.The probable cause may be listed below.
There is a leak in the oil line from the hydraulic tank to the pump.
There was a failure to correctly purge a hydraulic system after assembly, inspection, or testing.
There was a use of the wrong hydraulic oil that does not meet required specifications.The problem is a noisy pump.The probable cause may be listed below.
If all the pumps on the machine are noisy, there may be air in the oil (oil aeration).
If the noise is found to be only the vibratory pump, the probable cause is wear or damage to the pump.
The hydraulic oil is not at operating temperature.The problem is high hydraulic oil temperature that is above the acceptable range.The probable cause may be listed below.
The machine had one or more relief valves open too long during operation.
There is air in the oil (oil aeration).
There is a restriction to the flow of cool air through the oil cooler.
The ambient temperature is too high.
There is a restriction of the flow of oil through the oil cooler.The problem is a malfunction in the vibratory system.The probable cause may be listed below.
The vibratory switch on the operator console is in OFF.
The control panel circuit breaker was tripped.
The vibratory switch terminals are corroded. The wires are disconnected. The switch is damaged.
The vibratory solenoid control valve is damaged.
The vibratory pump is damaged.
The relief valve is damaged or the dump valve is damaged.The problem is turning off the vibratory system when the switch is moved to OFF.
Make sure that the electrical circuits are operating correctly.
Refer to the Specifications, System Operation, Testing and Adjusting manuals for the screed on your machine for additional information on the screed portion.