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Fixing the leak at the PS tank, thoughts?

Posted: Tue Nov 23, 2021 8:52 am
by ChrisZ
So I've been chasing a small drip in the power steering system for awhile. I finally know where it is: PS fluid seeps around the hose at the front of the PS tank and drips down to the bottom of the hose where it comes down right next to the alternator. Verified it by putting a paper towel around the tank fitting and it gets the PS fluid.

Do I need a new tank, or is there another way to seal that? Seems weird, was thinking of putting teflon tape or something around the tank fitting but curious as to thoughts.

Re: Fixing the leak at the PS tank, thoughts?

Posted: Tue Nov 23, 2021 9:07 am
by worf
Why not replace the hoses?

Which hose is leaking at the reservoir?

Re: Fixing the leak at the PS tank, thoughts?

Posted: Tue Nov 23, 2021 3:12 pm
by h2pmr
i would replace the short hose that goes onto the tank+ the tank itself.
the tanks on both of mine just seemed to go porous, as the fluid just seemed to come from the bottom of the tank.
hose replacement is a while you are in there

i think Roger does some OEM tanks.

cheers
Phil

Re: Fixing the leak at the PS tank, thoughts?

Posted: Tue Nov 23, 2021 7:05 pm
by worf
I have yet to see a PS Reservoir leak except at the hoses. I have yet to see one become porous or leak at the seams. On the other hand whenever you R&R the steering rack you are supposed to replace the reservoir (because of the integral filter) so I may not see too many original reservoirs.

The supply hose to the pump is expensive but available.

The return hose from the cooler loop ('87+) can be replaced by first cutting of the crimped clamp on the cooler loop and then either:
- buying a second expensive supply hose and cutting 'the middle' out of it.
- sourcing 10mm (IIRC) ATF-compatible hose and cutting it carefully to length so that went bent it doesn't come close to the fluid pump pulley.

For pre-'87s the return hose comes directly from the rack. I have see the rubber section replaced with hose and clamps.

All that for left-hand drive.

Maybe you right-hand drive folks get a different more-prone-to-failure reservoir?

Re: Fixing the leak at the PS tank, thoughts?

Posted: Wed Nov 24, 2021 2:53 pm
by h2pmr
porous might be a little strong, more of a sweat from the under side of the reservoir i fitted both hose's, cleaned the reservoir with brake cleaner and after a few weeks rubbing your finger on the bottom of the reservoir there was an oily residue.

fitted a new reservoir and all has been good since.

maybe they are still upset with us right hand drive folk about loosing something many years ago....and gave us the minderwertige Versionen.

cheers
Phil

Re: Fixing the leak at the PS tank, thoughts?

Posted: Wed Nov 24, 2021 6:20 pm
by ChrisZ
worf wrote:Why not replace the hoses?

Which hose is leaking at the reservoir?
Looks like the front most one with respect to the tank. This is an 86.5 so I don't know if it has a cooler or not. I'm kind of lazy this fall and feel like this should be fixable, why would it be weeping/leaking right at the tank?

Re: Fixing the leak at the PS tank, thoughts?

Posted: Wed Nov 24, 2021 7:29 pm
by worf
ChrisZ wrote: Wed Nov 24, 2021 6:20 pm Looks like the front most one with respect to the tank. This is an 86.5 so I don't know if it has a cooler or not.
You have to trace it. One hose goes to the pump. The other hose either goes back towards the firewall and then to the rack or routes to a hardline under the reservoir that then runs in front of the radiator.

I think your 86.5 does not have the cooler loop in front of the radiator.

ChrisZ wrote: Wed Nov 24, 2021 6:20 pm why would it be weeping/leaking right at the tank?
Because old hoses plasticize under the clamps and then leak. Those hoses from the reservoir tend to last 10 to 20 years before they leak.

Now, if the leaking hose is new, then maybe the clamp's loose or the hose is the wrong size. In the latter case, there was a run of the pump supply hoses a couple of years ago where one end (I forget which) was the wrong diameter and you had to use 27 ( :tongue: ) clamps on it.

Re: Fixing the leak at the PS tank, thoughts?

Posted: Fri Nov 26, 2021 10:21 am
by ChrisZ
Thanks Worf. I pulled the hose and sure enough the top of it is a mess. I tried cutting off the top 1/2 inch, but since it's a flared hose at the end, I don't know if the remaining amount is enough. The clamp covers it, but it doesn't go up to the top of the resevoir.

How much of a pain is it to switch them out and what percentage of the motor needs to come out to do it. The 86 model only has three hoses (tank to pump, pump to rack, rack to tank) and it looks like it's the tank to top of pump that is leaking. The big worry for me is the comments that the rack to tank return was an asbestos lined hose to go near the exhaust pipes, if that's not replaced properly then I might have a car-be-que.

Re: Fixing the leak at the PS tank, thoughts?

Posted: Fri Nov 26, 2021 12:09 pm
by worf
ChrisZ wrote: Fri Nov 26, 2021 10:21 am How much of a pain is it to switch them out and what percentage of the motor needs to come out to do it.
They are pretty easy when the motor's out :) except for the output hose on the pump.

However, they are just messy with the motor in. Mostly.

The supply hose to the pump: I always change that when I do a timing belt. The pump has to be loosened and moved around during a belt job and thus getting to the clamp on the rear of the pump is easy.

Whether or not it is easy with everything in place comes down to the orientation of the clamp on the pump-side of the hose. If it is oriented 'down' I have been able to get to it with a long screw driver from underneath by working through the lower control arm. You can see the clamp orientation from underneath.

If the clamp is not oriented down sufficiently then the pump/alternator cassette has to be unbolted so that you can move the assembly forward to get to the clamp.

The pump pressure hose is "fun" to get to under any circumstances.

ChrisZ wrote: Fri Nov 26, 2021 10:21 am The 86 model only has three hoses (tank to pump, pump to rack, rack to tank) and it looks like it's the tank to top of pump that is leaking. The big worry for me is the comments that the rack to tank return was an asbestos lined hose to go near the exhaust pipes, if that's not replaced properly then I might have a car-be-que.
The pressure line from the pump is the fire risk since it can spray high-pressure ATF on the headers.

The return line generally will just weep where the hose has plasticized under the hard line crimps.

Of course, if either hose simply bursts then you have a fire risk.

At this point in the life of all 928s, all hoses should have been replaced at least once already. Any that look original should be on your list of replacements. If there is cosmoline on the hard line portions where they connect to the rack then you know they are original. If they are obviously leaking then it doesn't matter how old they are.

Last, note that for the pressure and return lines you'll need 6 M14x18 copper crush washers; 4 for the pressure line and 2 for the rack return line.

https://www.belmetric.com/solid-copper- ... p-517.html