RS2 - rock hard brake pedal after refurbishing PAS pump

[JonRS2]

Thanks. In a month's time I will have owned the same RS2 for 15 years but it is certainly getting more difficult to do so. The X-plug has apparently been tightened much more than I had stated in a recent post and some locktite was also applied. The same thing has happened but even sooner: X-plug works loose and the hydraulic fluid leaks from there. It seems to me that there is either a problem with the particular X-plug and/or o-ring or there must be an occasional blockage somewhere in the hydraulic fluid system which is worse under pressure (more pressure now that the brake pressure accumulator / bomb has just been replaced). It is infuriating because it is so difficult to diagnose the problem. Even if it is just another faulty X-plug and/or o-ring, there is no guarantee that buying 20 X-plugs and o-rings and trying each of them will solve the problem (they could all be faulty). Or perhaps there is a problem with the hole in the tandem vane pump into which the X-plug goes? But that surely wouldn't explain why the hydraulic fluid did not leak at all for miles? From previous comments on the Forum even newly exchanged tandem vane pumps have had problems.

[JonJon 2.2]

I would contact a specialist on PAS pumps or get a "new" refurbished PAS from ZF if possible.
When my PAS broke down, I knew it was a expensive part. Audi wanted 1300 or 1400£. So I contacted the Norweigan ZF Importer. And I got the PAS for 275£. This is no longer possible in Norway. Audi have told ZF Norway only to sell PAS pumps to them. But perhaps it is possible in the UK.
Cheers and good luck with the PAS hunt

I went on the internet and found this:
http://www.zf.com/corporate/en_de/pr...n/SERVICE/list

ZF Servicecenter in Great Britain.

[A80Avant]

My pump problems, similar to yours ended up changing to a vaccum servo and a refund from audi for a pump they sold to me and still leaked. I had to change 3 brake bombs 2 pumps and 1 zf brake servo to go for a vaccum assist at the end and have no problems ever since

[JonRS2]

Thank you for your responses - much appreciated. The latest is that a new brake pressure accumulator (Febi-Bilstein 'bomb' through Amazon) and new high pressure hose (from Audi Tradition) and 4x new o-rings (from Audi TPS) were fitted. The hydraulic fluid system bleeds very quickly and the brake pedal feels fine. However, even with a third new X-plug and third new O-ring fitted to the tandem vane pump, hydraulic fluid is still leaking from around that X-plug. To make matters worse, the red (!) is now coming on even when the hydraulic fluid is above the minimum level in the hydraulic fluid reservoir. The mechanic thinks there must be a problem with the casting of the tandem vane pump (where the top X-plug and O-ring are inserted), which seems plausible to me. The hunt is therefore on for a replacement tandem vane pump. Audi want £1,234.94 for a new tandem vane pump (£144 of that is a refundable surcharge upon receipt of my old pump) and the Audi parts guy thinks that is perfectly reasonable given I have chosen to have a 21-year old car! I wrote an e-mail to Bosch 2+ weeks ago to try to source a new ZF tandem vane pump directly from them but have received no response. The mechanic is now trying to source an exchange tandem vane pump. With the benefit of hindsight, I would have sold my RS2 a few years ago when others on this forum did. As it is, road tax is up for renewal tomorrow and insurance in a few weeks. For I car I cannot drive and have hardly seen in months.

[Az786]

If you decide to sell it let me know I will buy it! Powerracksdirect.co.uk try them I ordered a recon pump of them for a customer they have them on the shelf the £170 inc vat exchange basis.

[k6kid]

I run a humble Audi 2.0 16v coupe but even so it shares many components with the S2. Included in these is the power steering and braking system with the dual pump. Some years ago i bought a second hand PS pump just in case i might need one. Don't know where you are in the uk but if you want to borrow it to try and help diagnose your problem then let me know. I am located in Worcester.

[Error404]

I have some S2/RS2 pump cores here, if you like I will try and repair/rebuild yours. If it doesn't resolve the problem then no charge

Alex

[twoqu]

I think thats a very generous offer from Alex.
Take advantage of it!
There is also a low pressure switch on the servo which would I think ping the alarm so its not necessarily the level sensor methinks. Logic obviously implies an issue with the pump and as its been dismantled and had several attempts at a common repair, it would seem prudent to concentrate on this part first.
I wonder if that plunger has been launched into orbit when the cap was removed originally. However pointless to speculate when somebody experienced has offered to help. That is if you want to keep enjoying the car.

[Rusty]

Alex rebuilt mine and it's spot on

I have a working pump taken off my car I could loan you if you want to start from a known point and see if it works.

There are 3 things that cause the warning: servo pressure switch; master cylinder reservoir level switch and PAS reservoir level switch.

The PAS reservoir level drops when you turn the engine on, so fill it to max at rest and it'll drop to min. Make sure you're using the correct mineral oil and not power steering fluid!

The switches are all open circuit in their normal state, so you can disconnect them in turn an isolate the culprit.

HTH

[JonRS2]

Thank you very much, Alex, twoqu and AndyC. Alex, I will be in touch by PM if I need to accept your kind offer. The latest information I have received is both good and bad. Good: apparently it is now possible to order a brand new tandem vane pump KS00001375 from Bosch for £250 + VAT (no surcharge and no need to return existing pump). Bad: Bosch are awaiting delivery of the parts and have no pump cores yet - estimated earliest delivery date of mid-April 2016 for a new pump. Good: apparently it is now possible to order a reconditioned tandem vane pump KS01001335 from Bosch for £200 + VAT + return of existing pump and/or surcharge of £55. Bad: Bosch are awaiting delivery of the parts and have no pump cores yet - estimated earliest delivery date of mid-March 2016 for a reconditioned pump. I am trying to obtain confirmation of this from Bosch as I have not received this information directly from them. Please treat this as rumour / speculation for the time being.

[twoqu]

As a sanity check I would take up both offers. Borrow Andy's pump and send your one to Alex. If the car then functions then you know its just a pump issue. In the meantime perhaps Alex can sort out your original.
Obviously without cores available then the leadtime could be extended. To be honest a lot of these so called recon pumps are nothing more than cosmetically improved with perhaps the seals changed without much consideration of any other inspection/testing. Hopefully Bosch would have a more stringent reconditioning process but without a core its a waiting game and its sounds like you are already fed up!
Just my 2p's worth!

[JonRS2]

Good points. I have sent PMs to AndyC and Alex. Thanks.

[twoqu]

Having re read your previous post it is evident that there are in fact no new pumps at all. If they have new pumps why are they waiting on cores? Seems a bit confusing to me. The issue is clearly the lack of servicable core, namely the front section I guess.
You either buy a new one with the surchage included or return your one and get the surchage refunded. Strange they have given 2 different p/n's but I guess that just for accounting rather than engineering.

Guess as a community we need to hoover up the Worlds supply of used pumps and control the supply chain, assuming we could trust a company to actually remanufacture then professionally.

[JonRS2]

E-mail confirmation received today from Bosch:

"I can confirm that the OE number (8G0145165X) cross refers to:

New product - KS00001375 – This part can be ordered through your local Bosch distributor. Please note the estimated delivery date will be around 1st April.

As well as…

BX re-manufactured product - KS01001335 - Historically the only distributor which stocks this particular product is Euro Car Parts however this part has been phased out of manufacturing."

[JonRS2]

At last I can share some happy news. Thanks to the thoughtfulness, kindness and generosity of AndyC who loaned me his working RS2 tandem vane pump and sent it to my mechanic who fitted it earlier this week, I now have a working RS2 with a fully functioning hydraulic fluid system - power to brakes and steering. The RS2 has now passed its MOT and has had a service too. I collected the RS2 this morning and had an enjoyable and stress free drive home.

The next stage is to send my faulty RS2 tandem vane pump, remaining seals from seal kit and collection of X-plugs and O-rings to Alex, taking him up on his thoughtful, kind and generous offer to attempt to repair it.

I am so grateful for the help and advice received through this wonderful forum.

Thank you to AndyC, to Alex and to others who have contributed.

PS: My original service stamp book "Service Schedule Avant RS2" now has all 24 "Proof Of Service' stamps in it. The back cover of the book states: "Service Schedule Avant RS2 english 1.94 951.563.8R2.20". Does anyone know where I can get another, similar RS2 service stamp book? Have they been NLA for years? Did someone buy the remaining stock from Audi? What do others do? Use a generic service stamp book when the original one runs out of space for stamps? Create your own additional pages for the original service stamp book? I have one year to find a solution. Thank you.