Ford 4000 Power Steering Leak Insanity

I'm at my wits end here. I bought a 63 Ford 4000 last year to use around the property. Over the summer I noticed that the power steering pump was leaking. It has the Eaton style pump with a reservoir on top. I bought a rebuild kit, replaced all the seals, O-rings, etc and put it back together. It worked good for a day or so but then started leaking again. Trying to pinpoint the leak is hard because the fluid is being slung off of the pulley and outward directed towards the wheel. It only leaks while running and is more pronounced when turning the wheels.

I thought I maybe screwed up installing the front shaft seal so I bought and installed another one. Same deal. It worked for a day or two and then started leaking again. I bought a third seal and had my dad watch over my shoulder as I installed it to make sure I wasn't doing something wrong. I started the tractor and as soon as I turned the steering wheel all the way to one of the stops it started leaking again. When I mean leaking, it isn't a little leak. I am loosing almost a quart an hour.

I finally bought a new pump, The pump from early 60s Studebaker and ford cars are the same Eaton pump so for $85 I figured I would finally put this issue to rest. I installed the new pump, drove the tractor for an hour and when bringing in a load of firewood the other night it started leaking again. Same issue where I am getting a constant drip/leak somewhere near the front of the pump and it is being flung outward by the pulley.

I need some suggestions as to what to do next. I was thinking maybe it is the pressure relief valve on the pump but then they both would have had to be bad on the old and the new pump. Is there somewhere else in the system that could be causing pressure to build up and drive a leak? Could I be doing something wrong when installing the resoivoir? The new pump did not come with it so I had to transfer it over (with new O-rings under the two holes). Are these pumps just prone to leaking like this? Is there a different pump or seal I can or should use? I'm using just regular power steering fluid. Should I be using something else?

Keith

you need to verify with Service Manual, but I 'believe' that Ford used hydraulic oil rather than ATF/power steering oil in those.

It is not uncommon for these pumps to leak between the pump and reservoir.

Overtightening the nut attaching the reservoir will warp the support plate preventing uniform clamping forces at the O rings.

Remove the reservoir and check the support plate on a flat surface. If not flat, turn it over upon reassembly and do not overtighten.

Additionally, check that the vent in the cover is functioning properly and/or do not over tighten the clamp for the cover.

Dean

Thanks. That is the sort of info I was looking for. I'll double check the plate. It seemed flat but it could have been slightly warped. Any reason to not put some RTV where on with the rubber seals that go between the reservoir and the pump?

I had the same thought on the vent during one of the 3 rebuilds. I drilled two small holes (one on the outside of the cover plate and one on the inside baffle. I offset the holes so that they didn't allow fluid to splash in there but I will check to make sure I still have free airflow to the outside.

Keith

Mine has always had hydraulic oil in it, not power steering fluid. Not sure if that will fix the problem or not.

They're O-rings. No goop.

Dean

Sorry. I was typing on my phone and it didnt come out right. I have the thick o rings in there already. I was thinking that some additional rtv might help where the other rings seal if the plate or bowl is warped.

Keith

Use the correct O-rings, no goop, and do not overtighten.

Dean

Ok. I removed the reservoir, checked to make sure it and the plate inside it were flat. No problems there. I then re-installed the square cut round gaskets (O-rings or whatever you want to call them) and put the resivoir back on. I tried to drain out as much of the power steering fluid as I could, replaced with hydraulic fluid and it is still leaking if not worse than before. It is fine when just sitting there idling. If I try to turn the wheels without moving forward or back it just starts spraying fluid all over the place. Best I can tell it is coming out of the shaft seal. This is a brand new pump doing exactly what the old pump did. It is like the pressure inside the pump gets too high and it starts pushing fluid out by the shaft. I'm at a loss as to what to do next. Any suggestions? Anybody put a different style pump on one of these tractors?

Keith

I pulled the new pump completely apart. Interestingly the internals are different than the old eaton pumps. Instead of rollers it has spring loaded flat blades inside of it. Those weren't the issue though. I suspected the safety relief valve because if it wasn't working then it would explain why the pump was pushing pressure out of the shaft seal. It came out of the bore but not without a little bit of effort. I polished the bore and the valve with some 1000 grit sandpaper to get it moving completely free. I also pulled apart the valve and shortened the internal spring by about a 1/8". I did the same for the external spring and shortened it just a little. It all went back together, got installed on the tractor and no more leaks (at least yet). I only ran it long enough to go get and bring in a load of firewood but hopefully this is a permanent fix. The tractor is just a little harder to steer with a fully loaded set of forks on the loader (probably due to the shortened springs) but I can deal with that as it is still easy enough to maneuver around one handed.

Keith