Help with 1979 John Deere 550 drives

[mjeselskis]

79 straight 550 Dozer. New brake bands, filters, oil,  etc. Left track has very little power. I tried adjusting the valve spool under the seat and the auto adjuster on the side of the frame. I can make it worse by tightening the brake band adjuster, but can't seem to get much power to the track.

[mike_belben]

The clutches had good amount of life left when you were in there right?  

Does that machine clamp by mechanical spring means and disengage by fluid pressure, or vice versa?

[mjeselskis]

It engages by hydraulic pressure. I didn't do the work, I'm just trying to get it working right for a friend after the previous mechanic said it was all set. Any way to check the clutches without disassembly?

[mike_belben]

I think the back of those machines comes off and exposes everything, i know a 550G does and its not nearly as bad as all the under the seat type access panels.  

If it applies power thru raising hydraulic pressure rather than venting it, the first thing is to see what the pressure in that circuit is.  There is surely a check port and a test spec.  Start there. 

[snowstorm]

if the old 550 was built like a 450 the wet steering clutches had a short hose running to them. if that leaked? or the fiber discs  are worn out. you describe it as one side slipping. its not a easy fun job to get at them. canopy and fuel tank platform need to come off