Power-Trac PT-1845 Articulated Tractor

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PT-1845 Repairing Loss of Steering Input

6/8/05 (651 hours) I had been noticing for quite some time, a year or so, that sometimes when I turned the steering wheel slowly to make a course correction the steering input would have no effect - the steering wheel would turn but the tractor continued on its merry way. It wasn't too troublesome - a quick jerk of the wheel and it would catch and steer fine for that correction. Often it would work just fine. Then suddenly the other day it got much much worse.

Disassembling the steering valve

Without giving it a great deal of thought I assumed it was the steering valve that was amiss. I took the steering valve off and started disassembling it. BOING go the little springs.

At this point I decided I needed expert help so I found the springs, got them back in place, and took the valve to the local hydraulics shop. This guy had never seen one of these before, took the cover off and BOING went the springs into his shop junk. While he was on the phone I found all the springs and ran. Even I can do BOING thank you very much.

Back home, I did some detective work and between the markings on the unit and Google I managed to identify the unit as a Parker Ross Hydraguide HGF and found a service manual. We now have an inhouse expert - at chasing springs at least!

I Found a broken commutator seal

Further disassembly revealed a broken commutator seal. After much searching and talking to several distributors, the quickest source for a seal kit turns out to be Power-Trac, who stocks them, for a small fee :-) Got the kit, got 'er all back together, installed.

It's all back together

Grrrr.... still no steer. You boob, you didn't do your diagnostic work! So I get some JIC plugs and caps and isolate first one steering cylinder, then the other. It turns out the left cylinder is leaking internally past the piston. Both piston seals had split. Another story for another day...

Parker Ross Hydraguide HGF parts

  • Marked on housing: HGF 16126 064 01 J
  • Parker Hydraguide HGF steering valve seal kit part number = SK 000097
    • Power-Trac part number = M14934-1 - $73.65 on 6/3/05
  • Download PDF version of Parker Service Manual:
    • From my site by clicking here to start a download
    • or for a fresher copy, go to Parker's site and download it by clicking on "Service Maintenance"