Slow left drive???

[jcriddl]

on my L785 the left side drive is very slow when driven by itself but when the right side is engaged the left sode will keep up but not pull its own weight. What could be wrong? Final Drive? Adjustments? Help please!

 

[Earthwerks Unlimited]

I'd first look for fluid loss--big time. Second, look at the control linkage. From there it could be a weak drive pump or drive motor, or a drive system relief valve opening too soon. Could also be a charge pump going or is bad.

 

[Tazza]

I'd first look for fluid loss--big time. Second, look at the control linkage. From there it could be a weak drive pump or drive motor, or a drive system relief valve opening too soon. Could also be a charge pump going or is bad.

The other option is a leaking internal seal in the motor. I had a machine that the wheels would spin great when there was no load, under load it refused to budge.

 

[jcriddl]

I also noticed today a couple of things that may help diagnose the issue. 1st---the left control valve seems stiffer than the right. 2nd---when at high idle the machine will not creep but creeps at low idle 3rd---seems to have more rear motion the forward motion

 

[jcriddl]

I also noticed today a couple of things that may help diagnose the issue. 1st---the left control valve seems stiffer than the right. 2nd---when at high idle the machine will not creep but creeps at low idle 3rd---seems to have more rear motion the forward motion

Just as a quick note *****the drive wasw fine before i disassembled the pump and changed the seals*****

 

[Tazza]

Just as a quick note *****the drive wasw fine before i disassembled the pump and changed the seals*****

What pump did you replace the seals on? the main drive pumps or simply the gear pump?
Air shouldn't be causing you these issues....

 

[jcriddl]

What pump did you replace the seals on? the main drive pumps or simply the gear pump?
Air shouldn't be causing you these issues....

I replaced the seals in the hydro pump closest to the engine.

 

[Tazza]

I replaced the seals in the hydro pump closest to the engine.

I'm still wondering of its just air.... It should self purge though. As for the lever being stiffer, i don't know how far you went with the seals, but if you removed shims, i assume you re-installed them too? to keep the same pre-load on the bearings.
I'm only guessing here though.

 

[jcriddl]

I'm still wondering of its just air.... It should self purge though. As for the lever being stiffer, i don't know how far you went with the seals, but if you removed shims, i assume you re-installed them too? to keep the same pre-load on the bearings.
I'm only guessing here though.

I purged the air and adjusted the linkage and it seems to be working for now. I tested the PSI on my Auxilary and only have 1600 PSI. The relief valve that is in it is stamped 2000 but not adjustable. What now??

 

[Tazza]

I purged the air and adjusted the linkage and it seems to be working for now. I tested the PSI on my Auxilary and only have 1600 PSI. The relief valve that is in it is stamped 2000 but not adjustable. What now??

I personally would give it a little time to ensure ALL the air is gone. If there is any air in the system, you will not get a true reading.