Power steering pump leaking

[NathanBS2]

Hi, took the car out for a blast to the Lake District yesterday and on way home power steering started to not be assisted anymore and eventually the brake pedal went hard. Pulled over and had no power steering fluid left. Did some reading on the forum and found out that’s what the problem could boil down too. Topped up with fluid today and fired engine up and it appears to have a pin hole in the pump next to the big cross bolt either that or the O-ring has perished.

I’ve checked on posts from previous years about the bolt and O-ring but can only find the discontinued part.

does anyone know where I can get a new replacement bolt and O-ring from?

kind regards

[JayCab]

This is what you need. Assuming your “pinhole” leak is actually the seals and not a real pinhole.

17mm ID, 2mm thick, 90 Shore value, made from Viton
https://www.polymax.co.uk/catalogsea...ult/?q=17X2V90


There used to be a repair kit comprising two new cross plugs with seals included.

The correct seals (these, ordered to spec), are critical. Do not use softer seals, sealant, goo, or any substitutes. They will all fail. Remove the plugs, clean the sealing surfaces up to perfection, then use these…
…this will work unless the pump has previously had poor work making this impossible.

You will have to re-use and clean up the plugs. You will also need special tooling to remove them. They are extremely tight (and supposed to be) Do not presume you can take them out with a big flatblade. It looks like an Ikea furniture plug at first glance. It is NOT!

I had this problem and double teamed it with my Engineer. I did the parts research at the time. He took the pump off and tooled it with these seals. Perfect! Not a peep out of it.

[JayCab]

In case you are not aware, it’s not power steering fluid, it’s central hydraulic fluid. Use VAG OE G004000M2 and nothing else on earth in this system, unless you happen to have an old bottle of original CHF11S Pentosin.

[JayCab]

From your description I’d be checking the whole system for leaks as well. To empty the whole system losing steering and braking, you would have to drain the better part of a litre of fluid. If it drained through a pinhole or slow leak, I’d have expected flashing red lights and warning chimes on the dash along the way to your situation.

A sudden loss of that much fluid may be a much worse problem than the pump plugs.

Also beware! Before working on this system make sure it is depressurised!! i.e pump brake pedal until hard so bomb is discharged.

It’s a 100bar + hydraulic system (read: positively dangerous)

[NathanBS2]

The brake pedal was solid from Sunday when I drove it home from the Lake District, was very sketchy. That’s where it lost all the fluid as it was a two hour drive home with fluid squirting out.

[NathanBS2]

Also I’ve had the flashing red light on for like 5 years since I bought the car but it’s never affected anything.

[NathanBS2]

Ideally I’m after a bolt/screw and seal kit brand new to swap both over

[JayCab]

Hi Nathan,

Sorry, I had to edit my post, I picked the wrong bag of seals out of my drawer!

You want these ones, not the 15mm ones I posted previously, you need 17mm ID:
17mm ID, 2mm thick, 90 Shore value, made from Viton (correct size, synthetic rubber (CHF wont eat them), hardest available (100bar won't blow them clean off))
https://www.polymax.co.uk/catalogsea...ult/?q=17X2V90

I left the rest of the bag I ordered with my Engineer. I'm happy to fish some back and send on to you free of charge if you like. Let me know.

I would be astonished if you find a pair of NOS genuine cross plugs for the tandem pump. If you do, buy me some as well please.

Flashing red light for 5 years. Wow! You may also be interested in the services of this fine gentleman:
https://www.autoaccumulators.com

kevin@autoaccumulators.com

+447895513800


Kevin Wright
Auto Accumulators
14 Crosby St
Stockport
SK2 6SH

If you send Kevin your brake pressure accumulator (Bomb), he can re-charge it back to factory pressure with nitrogen for you. This will likely cure your flashing red light. He's very friendly and accommodating, and will even send you a video of the before/after pressure testing!

I have used his services. Between the pump repairs, bomb re charging and correct fluid, I've got a flawless leak free braking/steering hydraulic system with no dash warnings.

The above products and services are probably as good as it gets for restoring this system back to spot on.

[NathanBS2]

Has anyone tried a copper washer instead of a rubber one?

[JayCab]

I have heard of this being done. However, when I faced the same problem I opted for replicating the OE design…

There are other folk who have welded or used metal epoxy to seal the plugs entirely shut, but this sort of thing was never going to be my approach..

The real problem is when the rubber seal is replaced with a substitute seal that is either the wrong material (natural rubber) or not hard enough, and it either dissolves or distorts with the 100bar + of CHF that sits behind it…

You need the correct seals, clean mating surfaces, smoothed threads, and the plugs tightened down hard on new seals soaked in CHF with tooling that does not destroy the cross heads (i.e not a big flatblade).

The leaks will then be history…

[nribs]

Agree with everything JayCab says. I've rebuilt two of these pumps.

For how much work is involved to get the pump off the car and on the bench, plus the absurd cost of CHF11, I would never mess with a metal washer or any sealing compounds. It's designed for the rubber washer and any small microscopic hole in the system will be a problem.

It's a finicky system and really only works the way it was designed.

[nribs]

Here are your rings...


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