3 cyl 4000 P/S pump seal leaking into engine

My 3 cylinder 73 4000 p/s pump is the new style with the integrated reservoir. It just started leaking into the crankcase. The last time I used it the steering all of a sudden got real hard to turn so I shut it down and checked the reservoir and it was so low I couldn't see any fluid through he filler hole. I pulled the engine oil dipstick and it was up several inches above full. I haven't run it since as I want to drain the crankcase and fill it with new oil before I start it up again, and before I do that I want to take care of the problem with the p/s pump so I won't have to change the oil yet again.

I see rebuild kits on line for around $10.00. Has anyone done a rebuild on one of those style pumps? How difficult is it? If it's going to be time consuming and still have a chance of leaking if I don't do something correctly I might just bite the bullet and buy a replacement. I see new pumps on ebay for under $150.00 including shipping. Are those inexpensive ones any good, or should I go with the one from this site for $222.00? Or the ones from CNH for over $500.00?

Thanks in advance for any information and advice.

You can try a seal kit - it may or may not work depending on the condition of the bearings. I would pull it apart and see what the bearings look like. If they are bad, spring for a new pump. If the bearings look good and feel tight, install a seal kit. It's not hard.

Our 3000 did that, too. In our case, the seal wore a groove into the shaft.

The rest of the pump was in ok shape so I took the shaft to a pro machine rebuilder (they rebuild large industrial machinery). I thought they'd do the standard things - weld the groove & turn the weld back down.

When I got it back, I found they'd cut a wider groove, then built it up with a flame sprayed-on ceramic (hard stuff!), then turned that flush with the shaft diameter.

I asked 'em why they did it this way and they said it's been their experience that welding a small diameter shaft sometimes causes the shaft to bend slightly, and rebuilding and remachining a bowed shaft then becomes a game of tail-chasing. From the welding I've done, I instantly knew what they meant. They said the ceramic is so hard, I'd be dead before the seal wore a groove in that spot again. Cost was $150, info I gained was worth a lot more than that.

I agree with Bern. My 4600 was leaking a little, so
when I had the pump off last winter while I was
rebuilding the engine, I resealed the pump. So far,
so good...

I have a 1971 5000 that had the same problem. Shaft grooved and bushings worn. Went with the inexpensive replacement E-Bay pump. Works great !
I don't know how it'll last but so far I'm happy. Pete

(quoted from post at 18:45:39 04/10/13) My 3 cylinder 73 4000 p/s pump is the new style with the integrated reservoir. It just started leaking into the crankcase. The last time I used it the steering all of a sudden got real hard to turn so I shut it down and checked the reservoir and it was so low I couldn't see any fluid through he filler hole. I pulled the engine oil dipstick and it was up several inches above full. I haven't run it since as I want to drain the crankcase and fill it with new oil before I start it up again, and before I do that I want to take care of the problem with the p/s pump so I won't have to change the oil yet again.

I see rebuild kits on line for around $10.00. Has anyone done a rebuild on one of those style pumps? How difficult is it? If it's going to be time consuming and still have a chance of leaking if I don't do something correctly I might just bite the bullet and buy a replacement. I see new pumps on ebay for under $150.00 including shipping. Are those inexpensive ones any good, or should I go with the one from this site for $222.00? Or the ones from CNH for over $500.00?

Thanks in advance for any information and advice.

Click to expand...

The kit has two shaft seals, one goes forward to seal in steering fluid, the other goes backwards to seal out oil.

I have had good luck rebuilding them. 40 year old seals get hard and start to chip apart.. (knock on wood)

Thanks to everyone for your input. I have decided that since my time is precious these days that I will be getting a new pump just to get the tractor running again, plus I'm buying the rebuild kit for the old pump. Then, once I have some spare time I will rebuild it and have a good one on the shelf for the future. That way will learn something new and expand my skills and experience without risking being without the tractor longer than might otherwise be necessary. Plus, I've found if I have a spare of something the one that I'm using never has a problem again, whereas if I don't have a spare then the "only one" I have of that particular something inevitably has a problem.

The one that's on there is not the original pump, but it is the same style pump as the original pump. The only reason that I know that it's not original is that the tractor used to be a state highway mower and the entire thing was painted yellow except that the wheels and a stripe on each side of the hood were blue. The highway maintenance guys apparently painted anything on the machine yellow after they finished working on it. The distributor cap, coil, generator, and even the spark plug wires were yellow when I got the tractor, except the p/s pump body was bare metal and the reservoir housing is black.so it looks like one of the 2 previous owners that had it before me and after the highway department replaced it.

I put one of those kits with the two seals in a pump a few years ago, and the two seals were thicker than the original one. I had to machine the housing a little deeper. Did you have the same problem?

I put new seals in one of those pumps and ran it for 4 or 5 years till I sold the tractor.
No problems in that time.
As for putting the seals in back to back, I never understood the reasoning for that.
Pump is putting out 600 psi (or thereabouts) and the crank case is vented so basically 0 pressure there. Since it is unlikely for engine oil to get pushed into the pump I would run them both so the PS fluid stays in the pump.