NOTE: The following procedure is for checking the main relief valve only. Use this procedure
when it is known that the hydraulic pump is in good working condition. If the hydraulic pump
is not working correctly, refer to checking the output of the hydraulic pump. (See HYDRAULIC PUMP Page 20-60-1.)
The tools listed will be needed to do the following procedure:
MEL 10003 – Hydraulic Tester
MEL 10006 – Hydraulic Test Kit
Lift and block the loader. (See Procedure Page 10-10-1.)
Connect the IN port of the hydraulic tester to the bottom (female) quick coupler (Item 1) [Figure 20-30-2] on the loader.
Connect OUT port of the hydraulic tester to the top (male) quick coupler (Item 2) [Figure 20-30-2] on the loader.
Open the restrictor (Item 3) [Figure 20-30-2] fully (counterclockwise) before testing the relief valve.
Remove the auxiliary hydraulics lock bolt. (See Procedure Page 10-140-1.)
Start the engine and run at low idle RPM. Push the right steering lever all the way to the right to engage the front auxiliary hydraulics detent [Figure 20-30-3].
Increase the engine speed to full RPM. Watch the flow meter on the hydraulic tester to make sure the flow is correct.
There should be 8.9 GPM (33,7 L/min.) free flow.
Slowly turn the restrictor control knob (Item 3) [Figure 20-30-2], on the tester, until the main relief valve opens. Record the pressure reading. The correct pressure for the main relief valve is 3000 PSI (207 bar).
