Powerfab 1200xd crawlers

[Nginmu Mbetse]

I think my machine is a 1200xd.. not 100% sure (pics of it on my other recent thread). Anyway.. crawlers have packed in, both sides.

1st to give trouble was the left side, went sluggish then finally all it does when you move the lever is occasionally 'pulse'. It tries to move but hasn't quite got the strength.

Then right side went much the same.

The lever plungers on the valve blocks go up and down ok & no oil leaks from them

Worn innards in the valve blocks? Burst pipes? Low oil? Trouble inside motors? Tracks too tight?

I found after it all failed, the hydraulic oil was indeed low so I topped it up to green, but no improvement. Can't readily see any obvious leaks from pipes. I did refit the left side track recently but the right side seems to have suffered just the same as the left, so I don't think it's purely due to my maybe overtightening the track?

Everything else works well apart from the crawlers.

Anyone have an idea what tends to go wrong and cause this on the Powerfabs. I had something similar happen on my old Nissan N120 & it turned out to be corroded 'top hats' inside the valve chambers. Are the Powerfab valve blocks similar, with replaceable parts inside the chambers? If so can you get spares easily or is it find a machine shop time..