Hydraulic System Tests

4.Remove cap (B, Fig. 528) on relief valve adjuster screw (C).

Tilt/Lift Cylinder Relief Pressure Tests

Lift Cylinder (rod end)

Tilt Cylinder (base end)

5.Using a flat-blade screwdriver, turn adjuster screw (C) clockwise to increase pressure or counter-clockwise to reduce pressure.

6.Lower the ROPS/FOPS according to “Lowering ROPS/FOPS” on page240. Restart the engine and perform a pressure test according to “Main Relief Pressure Test” on page288.

7.After the pressure is within the correct range, replace the cap over the adjuster screw.

8.If turning adjuster screw (C) does not change the pressure reading, check for the following problems:

NOTE: Possible hydraulic system malfunctions include, but are not limited to, the following:

•Possible relief valve cartridge on the control valve malfunction

•Possible hydraulic gear pump malfunction

Tilt Cylinder (rod end) bar (3448-3552 psi) bar (3448-3552 psi)

NOTE: Install tee fittings as required to connect pressure gages.

1.Early machines tilt cylinder base end is plugged; no relief.

Inspection

Inspect cylinders for physical damage/wear. Repair/ replace as required:

•Check that cylinder rods are straight and not bent/damaged.

•Check cylinder rod plating for damage/corrosion/pitting.

•Check the external cylinder tube for dents/ dings.

•Check for evidence of hydraulic oil leaking at the cylinder ports or the rod seals.

•Check cylinder rod/base end bearings/bushings for wear/play.