1994 Cat D5C Steering Issue

[77x]

Howdy. I purchased a Cat D5C (S/N: 9DL0730). It has a steering issue that I am trying solve. This is my first dozer repair but I have worked on lots of automotive stuff.

Symptoms: The dozer will not turn left. Turns right ok. When you apply only the left pedal the machine just comes to a complete stop. Another thing I noticed is that the machine will drift to the right when tracking straight forward.

What I have done so far: I inspected the linkages to the steering control valves and they look good. I took both steering valves off and inspected the roller bearing on the end of the spool and the cam lobes. I took the valves apart and they appear to be in good condition. The oil looked clean and I didn't see anything out of the ordinary (broken springs, bad O-ring, etc).

What I think is happening: I am thinking the left steering clutch is failing to release (or is totally jammed/welded solid) and only the service brake is working on that side. Maybe the hydraulic piston that disengages the steering clutch is shot?

Is there anything else I should check?

Is there anything else I should check before I tear it down more? Is it possible that I have multiple issues that present itself as one problem? I am on the right track?

 

[pittsburgh cat man]

You need to check pressure at the slave cylinders there is a tap on the outside of case by the track

 

[77x]

Ok that sounds good. I'm starting to believe that the right side clutches are the primary culprit since it is pulling to the right whilst tracking forward.

 

[Auctioneerhere]

You need to check pressure at the slave cylinders there is a tap on the outside of case by the track

Can you expand on what to expect if the pressure is off of what the book quotes?

 

[pittsburgh cat man]

If You see around 85 psi the transmission is at primary pressure. It is most likely caused by load piston orifice being plugged in transmission.