Instruction Manual

Caterpillar: Non-Confidential
Foam in the oil, abnormal sound coming from the oil, oil cylinders sometimes move and
stop while the steering wheel is being turned
1. Air in the system
1. Check oil level and add oil to the required
level. Check whether there is air leakage in
the suction oil and resolve venting the air out
of the system
Easy steering without load, heavy steering with load
1. Setting of the steering safety valve
pressure lower than the operation pressure
2. Steering safety valve is blocked
3. High oil viscosity
1. Re-adjust the steering safety valve
pressure setting
2. Clear the dirt off
3. Replace with the recommended oil
Heavy steering when the throttle is low, normal steering when the throttle is high
1. Low pump volume efficiency
2. Large clearance between the priority
valve spool and body
1. Replace oil pump
2. Replace the priority valve
No tactile operator feedback
Operation of the steering wheel is still light when the tires are at there limited steering
position
1. Pressure setting of the bidirectional
cushion valve on the oil port of the steering
gear is lower than that of the steering safety
valve
2. Severe wear and excessive clearance
between the valve body, sleeve, and spool, or
between the stator and rotor pair of steering
gear
1. Re-adjust the bidirectional cushion valve
starting pressure, which should not less than
1.25 times of the steering safety valve set
pressure
2. Replace the worn parts or the steering
gear
Steering failure
Steering wheel cannot return to the neutral position. The pressure drop increases in the
neutral position
1. Spring plates are broken
1. Replace the broken spring plates
Pressure run-out increases significantly, and even cannot rotate
1. Pin puller or drive shaft opening is broken
or deformed
1. Replace pin puller or drive shaft