Ford 4000 SU power steering problem

I've done a bunch of work to my 4000 SU this Spring and Summer, including (not limited to) new "freeze plugs", new hoses and belts, new steering wheel, fuel lines, valve cover gasket, oil pressure switch, etc, etc.

I've owned this tractor for almost 20 years. The power steering has never been quite right on it- it's always leaked and lost fluid, and I've thought it wasn't up to snuff- but it worked "some", and I've always been able to steer the tractor with no problem.

I had to do some pulling on the old steering wheel to get it off, and I did a little bit of pounding with a soft hammer and block of wood to try and seat the new one, as the splines on the column are worn off. I also topped off the power steering reservoir with hydraulic fluid. However, the tractor was harder to steer after I got it all put back together than it had been before. I didn't give that much thought-figured the cause would reveal itself in due time.

When I went out to mow a couple of days ago, I had some heavy mowing to do. All was well for about 30 minutes, then suddenly I was surprised to see hydraulic oil coming out from under the steering wheel and running down the column and gas tank cover. I had never seen this before.

I did some research on this forum, and someone had suggested changing the power steering filter- that the system might be building up too much pressure and blowing oil past the seals. So, I did that (changed the filter) just this morning, started the tractor up and there were no leaks.

So- I went out to mow again. The tractor was easy to steer, and all was well for the first 15-20 minutes, then I noticed hydraulic oil coming out at the power steering pump- it appeared to be coming out at the big O ring- where the reservoir/housing meets the pump. I kept mowing,and 5 minutes later, it was pouring out of the top of the column again! (The hydraulic oil was milky-looking).

Can anyone help me diagnose this problem?

I should have added- this is a 1970 3 cyl. diesel.

If the filter change did not solve the leak, you'll need to tear into it to replace the seal. Also, carefully inspect the shaft surface as
well and speedi-sleeve it if necessary.

(quoted from post at 15:33:56 07/31/20) If the filter change did not solve the leak,



you'll need to tear into it to replace the seal. Also, carefully inspect the shaft surface as
well and speedi-sleeve it if necessary.

Click to expand...

(on the steering collum is what Bern means)

Also the oring on the big reservoir cover is now leaking and that will need to be addressed?? If I read correctly. or... did you install the filter incorrectly and now fluid is squirting out at the filter, and hitting the vent and cap?? also... It very easy to strip the bolt out where it holds the big cover on the pump, so be very careful re-seating the big cover so you dont strip the back of the pump out. I would try to put the cover back on using a rubber mallet to tap it into place and then tighten the bolt carefully. Dont ask how I know this.

(quoted from post at 16:33:56 07/31/20) If the filter change did not solve the leak, you'll need to tear into it to replace the seal. Also, carefully inspect the shaft surface as
well and speedi-sleeve it if necessary.

Click to expand...

Thanks, Bern. Not the words I wanted to hear, but I'll do whatever I have to. I appreciate the advice, especially on inspecting the shaft.

Thanks Sotxbill. I was kind of hoping that these two leaks are symptoms of the same problem, but it sounds like I just have TWO separate leaks. I'll try to address the one at the pump and get it stopped before I tear down the steering column.

It's possible I didn't get the filter installed properly, and it didn't come with a new, large O ring, so I reinstalled the reservoir using the old one. I'll get a new O ring too.

Do y'all have any helpful advice on installing the filter? It was hard to keep it in place on the pump, while simultaneously managing the housing. I ended up sticking a long screwdriver through the bolt hole on the reservoir housing, which (presumably) guided the filter into place on the pump and also aligned the washer and spring. But, since I don't have x-ray vision, I can't really know that everything is properly lined up inside. The bolt threaded up with no trouble, and everything went into position without coercion. BUT, there must be a "trick" for doing this. Any suggestions?

I did some research, and realized that the parts store had sold me the wrong filter. I knew it looked different, but thought it was just from a different manufacturer. Turns out it wasn't even made for this pump. I've installed the correct one, and the leak at the pump has stopped. I mowed about 30 minutes yesterday without losing any fluid at the column, so I'm hopeful. We'll see. Thanks for the guidance, fellas. I'll try to update you once I have a chance to put it to the test.