Hydraulic System

5.7Check valve (load retaining valve)

• Boom cylinder base side.

A pilot-operated load retaining valve is used to prevent spool leakage, which allows the cylinder to retain its home position.

Raising the boom:

The oil opens the check valve and flows to the boom cylinder base side.

Lowering the boom:

The oil is released by the piston and returns to the tank using the pilot-pressure line. This reduces the load on the check valve. This allows the base side oil to flow back using the check valve. Boom base side Joystick control

5.8Flow rate adjustment of auxiliary hydraulics

The set screw on main valve block allows for changing auxiliary hydraulic oil flow at the ports.

Set screw – see Pressure limiting valves on page 5-8.

There are two possible positions: – see Auxiliary hydraulics oil flow* on page 2-3.

Important!

Do not position the set screws in between the two positions. This could cause the hydraulic oil to overheat.

Set screw “against hydraulic resistance”

The valve seat is closed in this position.

• P2 + P3 supply the auxiliary hydraulics section with oil.

• Factory setting.

“Open” set screw

Unscrew the valve seat by two turns

• P2 supplies the auxiliary hydraulics section with oil

• The oil supplied by P3 flows to the tank using the open valve seat.