Hydraulic System Tests

Cylinder Rod/Base End Pressure Tests

Pressure readings outside specifications could indicate, but are not limited to, the following:

•Internal/mechanical cylinder failure.

•Hydraulic pump malfunction.

•Joystick hydraulic leaking or other malfunction.

•Spool actuator/spring mechanical failure.

•Sticking main control valve spool, or spool not moving full range.

•Leaking/sticking relief valve.

•Low/incorrect port relief valve pressure setting. Refer to “Lift/Tilt Relief Pressure Adjustment” on page296.

Tilt Cylinder Base End Pressure Test

IMPORTANT: This test does not apply to early machines equipped with a plug in place of relief cartridge (A, Fig. 535) on the main control valve.

1.Stop the engine if necessary.

Caution

A pressure gauge with a minimum of 414 bar (6000 psi) is required. Damage may result to gauges if they are of insufficient capacity.

2.Using a tee fitting, connect a pressure gauge with a minimum capacity of 414 bar (6000 psi). into the base-end port connection (D, Fig. 529) on the tilt cylinder.

3.Run the machine until the hydraulic oil reaches operating temperature (approximately 60°C/ 140°F).

4.Use the hand throttle to set engine speed to low idle (1000 rpm).

5.Push the right joystick to the right and tilt the attachment hitch all the way forward until it stops.

NOTE: Raise the lift arm if necessary to allow the attachment hitch to tilt all the way forward.

6.While an assistant observes the pressure reading on the gauge, push the right joystick to the right. The pressure reading should be 237-245 bar (3448-3552 psi) with the engine at low idle (1000 rpm).

7.Release the right joystick.

8.Stop the engine and remove the pressure gauge and tee fitting from base-end port connection (D) on the tilt cylinder.