D3 Cat steering

D3

New User
Have a D3 dozer with steering issues after it is worked for an hour. I will be checking hydraulic pressures but first question. I'm getting a combination of mud water and oil in left clutch compartment. Cleaned it out when I had brake lining replaced but now an inch of water and sludge in compartment again. Left side only . Cover plate was tight and some gasket material used when bolted down. Any thoughts?
 
I take it you have the dry steering clutch set up? Is the plug at the bottom in place or taken out. W/o a plug it'll take it crud & water when working in mud. If you're working high
and dry it's good to have the plug removed to get rid of condensation. The pressure for releasing the steering clutches comes from the transmission and it's possible that you lack
enough pressure when the oil heats up. Maybe you know this already but there is a plug on the outside of the steering clutch compartment close to the rear sprocket. Attach a
pressure gauge there capable of 300 psi. You need 220 psi to release the clutches when the steering pedal is pushed down. This pressure is always the best when the
transmission is cold and should be checked with transmission at operating temp. It's possible also to have a little oil pressure leak in the steering clutch compartment creating
loss of psi. On one machine like this, I once had a pressure problem and it was a broken spring in the little control valve attached to the pedal under the floor boards. It was a
$2.00 item to replace and everything was good again.
 
What Nordic says. Beyond that, if your getting oil in the compartment, its very possible the slave cylinder that releases the clutch is leaking, and causing at least part of the problem once the oil gets hot.
 
There are three plugs in the area of the clutch compartments. Looking at a manual , it appeared that these were drain plugs for transmission or gear oil. I did unscrew the bolt that holds the brake band up which did drain the compartment. I just had a local mechanic pick the machine up. I will have him check the pressure when engine and system is warm. Do we need to operate the machine under load as opposed to idle to get the fluid hot enough to create my problem? I'll also have him check for leaks on the slaves as well. I did not see any cracks or plugs or missing plug when the clutch /brake assembly was removed a year ago. Does this machine have a separate pump for the transmission and if so is this something that can be rebuilt without taking out the entire transmission. You can tell by my questions that I am a novice when it comes to this machine so bare with me.
 
To get the trans oil warm in reasonable time you should work the machine somewhat similar to the work you do otherwise. I have never done transmission work on one of these
but I believe the trans. pump is directly behind the torque converter...personally i would find it easier to pull the engine to get at it than the trans. If the pressure is marginal with
trans warm, try to determine if the trans has very thin oil...if it does...change the trans oil and put in 30W engine oil as that will give better pressure when warm than thin oil. Don't
forget to check the control valves on the pedals under the floor boards.
 

Thanks for the help. I will pass this on to the mechanic. Will be back once initial trouble shooting is completed.

D3
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top