Hydraulic Supplier

[TOLEWIS]

I've been searching online for a hydraulic component supplier. I have a JD 550 dozer that the pump seal has gone bad. I'm loosing fluid from hyd tank and the transmission is filling up. Looking for a place that would have the pump and maybe the blade control valve.

[Jim B]

You need to use the parts catalog to identify your pump and valve, according to the parts catalog there were at least two different pumps, and two different valves used. Start with getting prices from your JD dealer so you have an idea if the price of an aftermarket one is fair.

Pumps can be rebuilt, and valves can be resealed. Does your control valve have an actual mechanical problem or just leaks? Rebuilding your pump and valve may be better options.

Here is a link to the online straight 550 Parts Catalog PC1437.

PC1437

[69_XS29L]

FWIW - Headed down this road for the similar reasons. Overheated the machine pushing on a hill end last summer. Had hydraulic oil leaking into transmission, apparently. Cheap hydraulic oil not a good substitute for TGH/trans oil in a pressurized clutch pack, is my current theory. Drained tranny and hyd tank, changed both filters, refilled all with PetroCan TGH. Loggers use it here, good winter performance. Pulling trans suction screen was an argument, not sure why.
My 550 still has a (possibly original) Cessna hydraulic pump, kits likely obsolete.
Northern Hydraulic in Great Falls can help, need original part number stamped on mounting flange, buried by lines and grease/dirt out of sight on top of pump of course.
Looking at a parts catalogue for a machine this old sounds like trouble. No telling if or how many times and with what the pump may have been replaced. Compatible shells do not necessarily mean identical internals.
Need winter to thaw enough to get a pressure washer in there and pull the pump, no running water outside currently, take pump back stateside in a couple weeks.
Northern also stocks a rebuilt replacement, Eaton or Danfoss, I believe. They are great to work with. See how it goes.