290 Hitachi Uneven Travel Speed

[Mess]

Hi folks, I have recently purchased a 290 hitachi with about 7700 hours on it. There is an issue and my mechanic has been on it for 2 days, hoping someone here my have had the same problem. The right hand track is slower than the left. To put it in perspective, if you went forward around 100 feet.... you would be going where you came from. It does it in both directions. The obvious have been checked, pump pressures, drives tested well, center joint is fine. Mechanic said it was going straight and fine for about 10 trips up and down the yard....I got in it and still pulling to the right. One thing that stands out is that the right track pedal/hand lever was replaced recently. No idea why it was replaced tho. TIA

 

[uffex]

Good day
You could try switching the pressure lines see if the problem moves to the other side,, if it does the issue is with the travel motor if not its further back in the system.
If you go excatech.org site common issues you can download trouble shooting to work through.
Kind regards
Uffex

 

[Mess]

Hi Uffex, the travel motors are within specs. Main pumps are within specs. Center joint is fine. It's the strangest thing, lift the machine up and 3 track rotations on each side take 34 seconds. Thanks for the website, I'll go check that out.
Cheers

 

[heymccall]

Measure case drain discharge per side @ travel motor.

 

[uffex]

Good day
It may be that. the rotational speed is Ok when you raise the track from the ground however under a loaded pressure may result it loss of performance. Most of that product line have variable displacement travel motors these can vary the crawler speed according to the required driving pressure.
I will check the archives to see ion we have better information. Question which model 290 have you ?
kind regards
Uffex

 

[uffex]

Good day
Checked the archive found the attached may help, I suggest you check the straight line results in low speed if the performance is correct it more probable that the pressure values for the travel motor swash are uneven.
Kind regards
Uffex

 

[Mess]

Hi Uffex, we are working on a ZX290-5 Hitachi. I will test the pressure sensors early next week. Thanks again

 

[Mess]

Well here is how the unit stands now: We had to do a little job with it and worked it for a while, the tracking is going straight now. However, when travelling with the machine the bucket curls closed very slowly by itself.

 

[uffex]

Good day
Check out the bucket spools, be sure these are free and the mechanism is free of defects.
Kind regards
Uffex