Caterpillar 320D Excavator Steering/Tracking Gets Stiff After Running for a While

[stephenrobinson98741]

I have a Caterpillar 320D excavator that’s been acting strange lately when turning and tracking. Sometimes it responds normally, but other times the controls feel stiff and slow, especially when trying to turn or move both tracks smoothly.

Hydraulic oil level looks good and I haven’t noticed any major leaks around the machine.

The issue seems to get worse after the excavator has been running for a while and everything warms up.

Has anyone dealt with something similar on a 320D before? I’m trying to figure out if it could be a hydraulic pump issue, pilot pressure problem, clogged hydraulic filter, weak travel motor, or something else. Any advice or experiences would really help.

 

[Simon C]

Post your serial number, post how many hours on the unit and I would suggest that you start with changing the hydraulic filters, if the engine is slowing down would be good to service fuel filters, are there any codes on the display.?
Simon C

 

[Simon C]

Forgot to say not to throw out filters without cutting open to examine. Too late once in garbage and gone.
Simon C

 

[Coaldust]

Might be running your chains too tight. The swing swivel might be leaking internally. Measure your track speeds with a stop watch and travel deviation and report back.

 

[stephenrobinson98741]

Might be running your chains too tight. The swing swivel might be leaking internally. Measure your track speeds with a stop watch and travel deviation and report back.

Ok I will check with this Point of View lets see what's comes

 

[ohdeereme]

I would lean toward the rotary manifold. Pick one track up off the ground and try to run the track on the ground slowly. If the track in the air moves there's definitely leakage in the rotary manifold.

 

[John C.]

I typically put a big load on the travel functions by finding a steep hill and try to walk up it. The machine will likely drift to one side. Write down what that is and then back the machine down the hill and turn the carbody around and then run back up the hill. Note which track is slow this time. The drift on only one track might indicate a slow pump. A drift that switches tracks is almost always the swivel seals. Next test to run is the case drains on the travel motors. Remove the case drain hose at the motor and cap the hose going to the swivel. Find another hose and connect it to the case drain on the motor and run the other into a bucket. Lodge a pin between the sprocket teeth and the track frame to hold the sprocket from turning. Now with the engine at high idle, rotate the sprocket against the pin and watch how much oil drains from the case drain. You should only get a dribble. If you get a lot, you have a motor problem. If the motors check out, do the same test at the case drain connection at the top of the swivel. A lot of oil there would indicate the swivel seals are bad. I have had the problem change tracks when I reverse direction and even had the problem change tracks while swinging the house while traveling.

After all that, most of the time we just pulled and resealed the swivel automatically without running all those tests. Sometimes it depended on the customer. For the ones who play the cheapskates or were slightly to mostly disagreeable to be around, I did all those tests and then always had to change the swivel seals anyway.