Published 08-25-09, Control # 077-04 2-53
RT9130E SERVICE MANUAL HYDRAULIC SYSTEM
CHECK VALVES
Description
There are five check valves utilized in the crane hydraulic
system. The check valves are used to block flow in one
direction and allow free of restricted flow in the opposite
direction.
The crane’s hydraulic dual return circuit has an in-line
plumbed check valve in one of the two return lines. It is used
to force hot return oil in the other return line to the hydraulic
oil cooler.
The swing/steer directional control valve has a check valve
installed in its outlet port to ensure there will be enough
pressure to force oil through the port anti-void check valves
for motor over run when the directional control valve is
centered.
There is an in-line mounted check valve between the
secondary ports of pump No. 1 and No. 3. It is used to boost
flow to the outrigger circuit.
The counterweight removal/cab tilt directional control valve
utilizes a check valve in its load sense line from the hoist/
telescope/boom lift directional control valve. It blocks the
load sense signal from the hoist/telescope/boom lift
directional control valve from bleeding through the
counterweight removal/cab tilt directional control valve’s load
sense bleed.
There is an inlet plumbed checked valve on the front steer
control valve. It prevents steering wheel kick-back if the steer
cylinder pressure rises above the inlet port pressure.
Maintenance
Removal
1. Tag and disconnect the hydraulic lines from the valve.
Cap or plug the lines and ports.
Installation
1. Connect the hydraulic lines to the ports on the valve as
tagged during removal.
2. Verify proper operation of the valve. Check hydraulic
connections for leaks.
To Next Page
Loading...
