2018 Toolcat 5600 2100 hours charge pressure dropping when warming up !

[oldnslo]

If dropping at low idle sitting still I would suggest checking both pump and motor case temps. Not moving motor in theory should have minimal case flow while pump has all of the charge flow dumping into via charge relief.

 

[RichardV-Quebec]

Gee, I thought it fixed itself for a while. I was able to drive for about 2 miles with 250-300 psi on brake line gauge and on T connector gauge of front motor hoses. It ran for about 15-20 minutes then at low idle pressure dropped below 70 and was hardly moving with high rpm. I did not have the laser temp gauge with me but putting my hand directly on the back of pump felt pretty hot. The cooler fan was turning. Engine temp was normal. Hyd eyesight normal. I did not get to capping the P1 line on the pilot manifold yet.

 

[RichardV-Quebec]

I thought the moving problem was only when the TC gets warm but in fact, even when cold it will not move on a small hill or bump. It feels like it is not having enough hydraulic power and when trying to go up the small hill, there is a slipping or grinding noise coming from the front below the console and at the same time the charge pressure drops a lot. As soon as I let go the drive pedal, charge pressure comes back up. While the moving problem occurs, steering and front equipement are fine.

 

[oldnslo]

It sounds like you have a bad hydrostatic pump or drive motor or possibly both since frequently when one component fails it contaminates all the drive components in the circuit.