anyone done a PS pump rebuild?

[cbose]

Not exactly an engine issue, but I can't find a better place for it

Car: 91 Legacy SW, non-turbo, 196,000 km

Problem: Prepurchase check mechanic said that my power steering pump was 'getting pretty noisy', among many other things he didn't like. It makes a low whine at all speeds. Doesn't look too hard to take apart and rebuild, BUT, has anybody actually done this. What is likely to be worn and can it be replaced with a rebuild kit or off the shelf parts?

Related problem: PS rack is losing quite a lot of fluid. Appears to be flowing out of the end boots and also (possibly) from the upper seal on the input shaft. I plan to swap out the rack for a low mileage one from the wrecker, but I want to make sure my pump is working first and especially that the bypass valve is kicking in.

I already asked this question on the NASIOC so apologies in advance if you saw it there.There was very little response, perhaps because their focus seems to be more on newer cars and mods.

Thanks in advance.

[mTk]

I've never done a rebuild, but gettting a new/working used pump is probably a lot more convienent/cheaper.

My original pump was making some noise so i swappe dit with one from a salvage yard, has been working fine.

MK

[Legacy777]

you really can't rebuild them, or should I say...you'd have a hard time finding parts to rebuild them. You'll be better off just buying a new one. I priced them, and they were around 200 or something for a reman.

Sounds like you need a new steering rack as well.

You could look at junkyards. I put a used pump in my car, you could pull a rack off a newer model legacy GT or impreza, and they should fit, and you'll get quicker response due to a quicker rack.

[evolutionmovement]

Where'd you find the pump for $200? Up here thy're all $400+ and mine's making noise at low speeds and when cold. I suppose I could drain it and run it as a manual rack, but I'd rather not.

Steve

[vrg3]

Advance Auto Parts has remanufactured pumps for like $100 plus core.

[evolutionmovement]

Thanks! I'll give them a shot. Ther's a small one a few towns over. Hopefully they'll have the same pricing.

Steve

[Legacy777]

yeah....new may be that much....a reman one will work just fine.

[vrg3]

Steve, you can go to their web site and it'll look up inventory in your local store for you.

http://www.partsamerica.com/ or http://www.advanceautoparts.com/

[entirelyturbo]

My Legacy's pump used to make noise, and has stopped. It made the most noise when I had the big fat rims on it (205 width versus 185)...

I have a junkyard PS pump sittin in my garage too, just waitin for the old one to crap out

The steering gear boots are a snap. That was my XT's big problem when I got it, they were literally in pieces and spilling ATF all over the exhaust manifolds I changed them both in a half-hour.

But if you're leaking in other areas, yeah, just swap the whole thing out, not worth messing with...

[Legacy777]

Michael,

Have you pulled the belts off and tried to spin the PS pump by hand......it may be worse then you think. Mine made noise, then stopped....and made noise again......you could barely turn it by hand.....bearings were all tore up. Hopefully it didn't damage the rack.

As for replacing just the boots on the rack. If the rack is leaking, the rack itself is bad. It should not leak atf fluid

[entirelyturbo]

Yes I have, I just did as a matter of fact, when I took my A/C compressor off, it had no trouble turning at all, no grinding noise either...

I haven't had any whining noises in a while, but on a very rare occasion, after the car has been running awhile, I can turn the wheel and literally vibrate the car with a horrible and very loud moaning and groaning...

[cbose]

Thank you all for some helpful info on the PS pump rebuild project.

I'll give it a spin with the belt off this weekend and see what I find.
If it is bad, then I should start there before messing with the rack.
There are THOUSANDS of legacy sedans and wagons down here
so no shortage of wrecker parts as well as independents who rebuild
cores. Doesn't sound like I should bother visiting the dealer if I need
a new pump. FWIW, a quick search on the impreza list uncovered
a guy in Australia (sorry, don't remember the name) who had
rebuilt pumps using generic bearings and a bit of machine shop time.
Sounds more like something to do just 'cause you can, rather
than a practical approach.

The leaks from the rack are surely more than the boots can handle.
As I understand it, the boots are there to keep dust OUT, not fluid IN!
On top of that, there is uniform play at the pinion all along the rack.
I know that can be taken out, but a transplant from the wrecker will
make a lot more sense.

I have another question about the 5MT on this car which I will post
to the drivetrain forum. Once again, thanks.

Chris

[Nigel]

I rebuilt my pump last year for a grand total of... $10CDN!

As I was tearing down the front of the engine of my ’94 Legacy turbo in order to replace the timing belt, I discovered that my power steering pump had been leaking everywhere and had made a huge mess. The best price I could come up with for a rebuilt pump was $120US, or $200CDN for me (new is $270US!), and I couldn’t find a rebuild kit.

Figuring I had nothing to loose, I decided to open up the pump and see what was what. Mechanically, the pump was fine. There was no scoring or pitting or any damage to speak of. The only thing that was wrong with it was that the gasket, o-rings, oil seal and the shaft bearing were worn out. The gasket is metal with a rubber inner lip (like an o-ring), so I figured that a bit of sealant would fix that up. The oil seal and bearing had part numbers on them, so I headed off to a local bearing shop and they had the bearing in stock for $5CDN. I was sent off to another store for the seal (another $5CDN), and they gave me the o-rings for free (they are metric o-rings, so you may have some trouble finding them). So, for a grand total of $10 (not including the sealant for the gasket, which I already had), I was able to rebuild my pump!



Below is a parts list. Please double check everything, as I made the list from memory!

O-rings:

50mm id x 2.5mm – 1 req.
15mm id x 2.5mm – 2 req.
19mm id x 2mm –1 req.

Bearing:
NSK (or equivalent) sealed 6203
40mm od x 20mm id x 10mm h

Oil seal:
NOK (or equivalent)
36mm od x 20mm id x 7mm h

[THAWA]

I'm curious as to how much the ps pulley should spin when you take off the belt.

[vrg3]

Nice! Great job. Thanks for posting the info for the rest of us.

[cbose]

Thanks Nigel! That was a great post, and exactly what I was looking for. Perhaps now
that I know what is inside, I can try to order the pump body gasket from the dealer
well in advance. Yours was salvegable, buy it looks like it could tear on disassembly
pretty easily. Here in NZ, everything is metric so the o-rings should be a snap.
Having the bearing numbers in advance is a great help. Another
description I saw had to substitute a larger bearing, and a machining job on the
housing. N6203 sounds like a pretty common bearing though. From the pics
it looks like the rear bearing is a bushing.

Now that I think about it, I believe the other guy
suggested to replace the rear bush with a needle bearing and THAT
of course requires you to bore out the cover a bit. However, even if the rear
bushing is bad, there is a way out.

Looks like the rear bearing is 'blind' so there is no need for an oil
seal there.

Over the weekend I had a good look at my pump. It spins fine -- no binding or
roughness. When the mechanic pronounced it on the way out, it was low by about
1/4 litre of fluid, which I subsequently filled up. I don't really hear much noise from
the pump now so I'll concentrate on the rack, which continues to drip out fluid
onto the exhaust at an annoying (but low) rate.

Given Nigel's description, I might pick up a
core pump from the wrecker along with the rack and rebuild it just for fun!

Cheers, and thanks for a great line of posts from everyone.

[entirelyturbo]

Definitely some awesome info, Nigel!!! I think pretty soon, I'll tear apart the one I got from the junkyard and rebuild it, then swap it out and appreciate a "new" PS pump for far cheaper!

Just be prepared to hang around just in case some of us get elbow-deep in it and get confused somewhere

[Nigel]

Thanks guys! I'm happy to help when I can...

You should really have no problems finding the bearings and seals. Bearing and seal sizes are pretty standard and are manufactured by many different companies... SKS, NSK, FAG, etc. Hell, I tore apart a 20 year old Nissan alternator, and the local bearing place had those bearings in stock too!

Chances are, the bearing in your ps pump is shot after that many years. When you pull the shaft out and spin the bearing, you'll be able to hear the balls whirling around. If it's really bad, it'll feel 'crunchy' as it turns

Cbose... I don't think you'll need to order a new gasket. Like I said, it's metal, so it won't tear. Just don't jam a screwdriver between the housing and cover and muck it up

Nigel
'94 Legacy Turbo
'73 Datsun 240Z Turbo

[cbose]

NIgel gave us some good shots on the PS pump. I gathered parts and finally got around to doing the job only this weekend. Did it go? The short answer is yes and no. If you want to do this here are some things to be aware of. I got a lot of info from a friendly steering shop when I discovered the parts I bought were all wrong for my pump. . . .

1. There is a wide variety of pumps being used. The part number on the pump may not clarify the situation, according to the rebuilder. They have all parts on hand to deal with 'surprises'.

2. Shafts are either 15mm or 20 mm diameter, corresponding to the front bearing as 6202 or 6203 respecively. Bearing must be fully sealed as it sits at the very front, outside the seal. This is actually good, as you can pull the pulley and have a look at the bearing number before you pull the pump.

3. Shaft seals are either 17, 18 or 20 mm ID. Even the experts can't seem to tell before the pump is apart. Also, there are many kinds of seals. Low speed, high speed, high pressure . . etc. you need high speed, high pressure.

4. I ended up replacing at least 8 o-rings on my pump. I got them all from the rebuilder. He did it by memory! and got it right.

Assuming you have the right parts in advance, a couple of points about the R&R

1. I could have reused the gasket, as Nigel said, but as I had no backup car if I messed up, I had a new gasket on hand and used it. Fitted it dry. It was half the cost of the $50 rebuild.

2. the bearing/shaft assembly was very difficult to get out of the housing. A press would be the right way. I used a combination of vise and hammer

3. getting the bearing off the shaft was worse. Definitely a press. I used a vise and hammer again, and I am not proud of it! I had to fabricate some pipe sleeves so as not to stress the new bearing on reassembly.

4. Once apart, everything went back together smoothly, but again, bearing to shaft
and bearing to housing are drive fits, so think ahead!

In summary, this turned out to be more of a white knuckle job than I would have liked, but mostly due to a lack of tools, and the fact that I had no backup transportation and needed the car the following morning! With a well-equipped shop (read press and lots of fixtures) it would be a snap. Without the press, it will be ok, especially if you did this with a rebuildable core from the wrecker while your old pump sat quitely and watched from the engine bay. In the end, my pump is quiet, it works, and it doesn't leak . . . yet.

Chris

[entirelyturbo]

Thanks, cbose, for the tips! It sounds like it was definitely some work. I plan on doing this before the year is over, just for kicks and giggles. I wonder how much it would be to have a shop press the shaft in and out of the bearing...

especially if you did this with a rebuildable core from the wrecker while your old pump sat quitely and watched from the engine bay

This is my situation. When I had my Rotas on the car (2 in wider than stock) it was putting some extra stress on the pump and making noise. I bought a junkyard pump for $25 and then when I took the wheels off, the noise went away Haven't had it since. But I'm going to give it a shot anyway, if just for the lesson on how to do one

[tonflo]

I had mine rebuilt a couple of years ago. I ordered the shaft & bearing as 1 piece from Liberty Subaru. I think it was about $40. It turns out the shaft was different than mine so my mechanic just pressed off the bearing & reused my shaft. It was nice & quiet after that. For anyone that's interested, Liberty Subaru sells at wholesale if you mention that you saw their ad in Autoweek. 1-888-SUBY-4WD. They ship pretty quick too.

[cbose]

subyluvr, I'd just go ahead and try it at home. Part of the fun is making do with the tools you have. (Even if it takes a couple of days of headscratching to get it done.) Of course, professional mechnics have a completely different objective; they need the tools, or farm out the job to someone who has them. For them, time is money! For us, a few blocks of wood, pieces of scrap aluminum and a light touch with a propane torch, combined with a strong dose of 'I can do this' and some patience will often be all you need.

A couple of slightly non-obvious things I forgot to mention. Take the back off the pump first. Then remove the inner stuff, the vanes, impeller and inner race. Take care as these parts are almost, but not exactly symmetric so match marks might be a good idea. The shaft and bearing can be pushed out of the front housing in the forward direction after the bearing circlip is out. If it doesn't budge, a gentle bit of heat on the housing bore might help. The shaft has a shoulder behind the bearing, so pushing this way is the end of the road for the bearing. Of course you will be replacing this anyway. There was a large spacer washer hiding behind the bearing on my pump.

A selection of thinwall tubing bits is really handy for reassembly, one to fit the shaft and inner race, the other for driving the bearing back into the housing via the outer race.

Enjoy!