Cat D3 Steering Problem

Tweeter · Mar 31, 2014

I have a CAT D3 79u that is having problems steering. The steering valves appear to be free moving with no leaks. Stem has some wear but is within tolerance with pedal position. When pedal is pushed enough just to push in on the stem nothing happens. The pedal has to be pushed completely down to "brake" or lockup the track to turn. Sometimes after doing this I release the foot pedal and the same track seems to be locked up or braked and the only way to get it to start moving again is to either quickly depress and let off the opposite foot pedal or center brake pedal. When doing this loud screeching noises are heard.

dpendzic · Mar 31, 2014

I am no expert but the roller cams on the end of the valve stems should be checked out---do you have dry or wet steering clutches?
screeching noises may be from no brake lining and brake band steel on brake/clutch drum

Tweeter · Mar 31, 2014

There are no roller cams on the stems of these control valves. The pedal just pushes directly on the end of stem.

EricB · Mar 31, 2014

I've been through similar variations of these problems. These are dry clutches and don't always take well to aging. With rust and deterioration the clutches sometimes don't fully release and when you step really hard on the pedal the discs groan from too much friction. I've also had it where proper clutch pressure does not fully return due to a tiny spring being broken in the steering valve. There is a small pipe plug on each side of the outer housing facing the tracks. If you attach a hose with a pressure gauge there capable of 300 lbs start the machine and depress the pedal on the same side as the hook-up, you must have a minimum of 220 lbs for the clutches to release and must return to 0 lbs as soon as you take the foot off the pedal.

Tweeter · Apr 1, 2014

Is the loud groan a problem that needs to be fixed?

Old Magnet · Apr 1, 2014

Check the slave cylinders that operate the steering clutch release yokes. They have been known to hang up even if pressures are right.

Anonymous-0 · Apr 1, 2014

Free up and lube all linkage pins outside and inside the clutch covers and see if that helps.
Later Bob

Tweeter · Apr 1, 2014

When you say check do you mean pull the covers and inspect?

EricB · Apr 1, 2014

The loud groan I'm referring to is if the track is held still by the brake pedal fully depressed while in gear and a bit of throttle, if the track is partially moving the groaning can be from the brakes also. The noise from the steering clutches doesn't have to be fixed if the machine pulls and brakes properly but will make them wear prematurely as the discs are not fully released. With engine running depress both pedals all the way and hold, then put it in first gear forward with a bit of throttle - if the machine tries to move forward one or both clutches are not fully releasing. If you have to press hard to keep it from moving this is when you may hear the groaning and often feel a bit of vibration coming from the pedal with the slippage. Hook up the pressure gage to that side as I described in the previous email. With engine running push the pedal 10 or more times while watching the gage...it should go to 250 lbs or more when cold and as soon as the pedal comes up all the way it should go back to 0 lbs. If it does every time the steering valve works fine.

Old Magnet · Apr 1, 2014

Yes, and observe them operating.

Tweeter · Apr 2, 2014

I checked the pressure on both sides. Both sides are the same, as soon as i push pedal down gauge goes to over 250 psi and back to 0 psi when I let off.

Cat D3 Steering Problem

Tweeter

Member

dpendzic

Well-known Member

Tweeter

Member

EricB

Member

Tweeter

Member

Old Magnet

Member

Anonymous-0

Well-known Member

Tweeter

Member

EricB

Member

Old Magnet

Member

Tweeter

Member

Similar threads