VALVE GP-RELIEF 3P3319 - Caterpillar

Illustration 2 g01386616
(5) The test point for the ejector control valve is located above the ejector control valve. The cab is raised for photographic clarity.In the hydraulic system for ejector cylinder (1), there are two relief valves in ejector control valve (10). These two relief valves regulate the pressure for the piston side of the ejector cylinder.
Main relief valve (7) regulates the pressure from gear pump (9) that supplies hydraulic oil to the ejector control valve. The main relief valve should be set at 17240 345 kPa (2500 50 psi).
Port relief valve (4) regulates the eject pressure of the ejector cylinder. The port relief valve should be set at 17580 345 kPa (2550 50 psi).In order to test the settings for the two relief valves, use test point (5) for the ejector control valve. It is not necessary to use test point (2) on ejector manifold (11). This is because of a direct oil path between the test point and the piston side of the ejector cylinder when the valve spool of the ejector control valve is in EJECT position (6) .In order to test the setting of the port relief valve, the machine needs to be at high idle and the ejector blade needs to be held in the fully ejected position with the ejector control in the EJECT position.
Illustration 3 g01386622
In order to test the setting of the main relief valve, the machine needs to be at low idle and the ejector blade needs to be held in the fully retracted position with the ejector control forward of the normal RETRACT position. Refer to Illustration 3.Perform the following procedures in order to set the two relief valves. Ensure that the two relief valves are set in the correct sequence.Test and Adjust the Main Relief Pressure
Ensure that the oil is at operating temperature.
Park the machine on a level surface. Move the parking brake control to the ENGAGED position and move the ejector control to the HOLD position. Shut off the engine and then install the steering frame lock. Refer to Operation and Maintenance Manual, "Steering Frame Lock".
Install a pressure gauge on test fitting (5) for ejector control valve (10). The pressure gauge must be capable of measuring 34000 kPa (5000 psi).
Illustration 4 g01385671
The lever is fully forward beyond the normal RETRACT position. There is no detent at this position.
Start the engine and move the ejector control to the RETRACT position.
When the ejector blade has reached full travel, run the engine at low idle. Hold the ejector control forward of the normal RETRACT position. Refer to Illustration 4. Record the pressure that is displayed on the pressure gauge. This is the pressure setting of the main relief valve.The setting of the main relief valve should be 17240 345 kPa (2500 50 psi). If the setting is correct, proceed to "Test and Adjust the Port Relief Pressure".If the setting is incorrect, the setting must be adjusted. Proceed to Step 5.a.
Shut off the engine and then raise