Power Steering Pump follies

XJ-S
1

Hi All,

XJSdad here - I haven’t posted in a long time, so I apologize for that! Our project (rehabilitating my son’s 1989 XJ-S which he purchased in 2014 with a dropped valve seat) has been moving along with great success, and we finally started the engine a couple of weeks ago and are just mopping up a few minor coolant leaks and vacuum leaks. We have done almost every update/upgrade/refurbishment discussed in this forum and in Kirby’s book and a few others I’m sure!

We have one really annoying problem that I’m hoping someone can suggest and idea for - we rebuilt the Power steering pump, replaced all the lines/hoses/insulation, and replaced the tower shaft seal on the rack (with a modern shaft seal rather than the original type). When we got it all up and running - no power steering assist!

So far we have not been able to get the system to bleed or find any other issues, so we are assuming that the problem must be in the pump since that’s the only part of the system we really took apart. We took the pump out and observed that when we spin it by hand as fast as possible (reservoir full) that it does not produce any flow or pressure at the output fitting. OK, that would cause no assist! We have also observed that when the car is just sitting (which it has for some months) with the PS reservoir full, the fluid slowly leaks out around the tower shaft seal. I am wondering (hoping?) if the two problems (leak when sitting and no assist) are both related to the pump. It seems like the vane type pump, if working properly, would isolate the reservoir from the rack when the pump is off. Thus I would not get the leakage at the tower seal (and honestly, I don’t think any shaft/lip seal is designed to seal against a static head) if the pump was working properly, and I would get PS assist in the bargain!

Any thoughts would be greatly appreciated! I have ordered a reman pump from Rock Auto, but hate to give up on the pump we have as I really cannot see anything physically wrong when I take it apart. Let me know what you think.

Best,

Gary S.
1989 XJ-S

2

Two things can be wrong.

Incorrect assembly of the body and plates around the rotor, the holes have to line up in the right way.
It is a bit of a puzzle how they all go together.

The pressure relief valve can be assembled incorrectly - did that once.
There might be a Youtube video on the subject these days…

3

Hi Richard,

Thanks very much. That is a possibility. When I opened it up I had the
impression that dowel pins were not in the holes in the pump housing. If
true, that would have misaligned the suction and pressure port’s and caused
the symptoms we see. When I reassemble it I’m going to put those in with
sleeve retainer. I’m just crossing my fingers that getting the pump fixed
will stop the tower seal leak.

Next thing to sort out, how come we see coolant I’m both air cleaner
housings. Checking now to see if it could be coming through the o-ring
seal in the AAV. Any other thoughts on that one?

Thanks!

Gary

4

  1. Just looked at Youtube, plenty of hits for “GM power steering pump”.

  2. Tower seals normally do not leak at all unless fairly old.

  3. Not sure about coolant in air cleaners, you might be correct about AAV.

Good luck.

5

I did find some possible concerns inside the PS pump when we took it apart, and so we ended up installing a reman pump from Rock Auto with only the fairly minor issue that the original pump was threaded for metric fasteners to mount it to the brackets and the reman pump was threaded for imperial fasteners, so needed a trip to the hardware store. Unfortunately the new working pump revealed that there’s a massive internal leak in the rack in the valve area which rapidly pushes all the fluid out around the tower shaft seal and onto the floor. So, the rack will need to come out for a rebuild. More to follow!