964 C4 brake booster pump issues

[hughdixon]

The brake booster pump on my C4 (part number 99335595301) was leaking hydraulic fluid through the seal between the motor and pump but otherwise was working ok. I have had the seal replaced as didn't want to pay out for a complete new unit given the price - upon getting the car back it was running great, however the next time I took it out, there was no braking worth speaking of, an interesting experience today the least !
The garage who overhauled the pump have tried to rectify this , they have established that the pump is working however it appears not to be pumping at sufficient pressure hence the brakes not working.
I reached the stage today where I decided to bite the bullet and order a new pump from my local Porsche dealership only to be told the unit was not currently available either in the UK or from Germany, this has also been confirmed by Design 911 and also Champion-Porsche in the USA with no indication from Porsche as to when or if they will become available again.

My question therefore is two fold, namely:
Has anyone got any suggestions where I could source a new or second hand unit preferably in the UK, or any ideas why the pump doesn't seem to be pumping at sufficient pressure to enable the brakes to work as they should ?

I believe there are a number of other UK owners with back orders for these pumps so maybe someone can answer my questions.
Thanks in anticipation
Hugh

 

[mcgc0]

Have you tried sourcing an used unit from one of the better known 911 breakers?

Was it the UK OPC that said none were in Germany either? If it helps I have a Porsche Classic Centre contact name in Munich which I have popped in a few times for while working in Munich. Maybe they know how to get hold of a replacement (new or otherwise).

 

[hughdixon]

Hi, thanks for the response.
I spoke with Silverstone Porsche who I have used previously for parts who said there were none available. I have also spoken with design 911 and a big dealership in the States as well as Pelican parts, all came back with the same response.
Yes I have tried the 911 breakers who all had a chuckle when I said what I was after so am now looking further afield.
I contact in the Porsche Classic centre would be useful if you could let me have it.
Whilst I would hope Porsche would start supplying the pump again at some point, if they don't then that presents me with a bit of a problem !
Thanks again

 

[mcgc0]

Does seem daft that the whole world's existing C4's could be unusable if the high pressure pump failed and nothing can be done about it. Would have thought that someone somewhere is repairing these items. Might be worth checking in with Tore Bergville and asking the same question - he seems to know everything re 964 diagnostics etc.

Munich Classic Centre part manager contact is Markus Rieger - markus.rieger@pzm.de I popped in and asked about some 968CS parts back in October. They had a 962 for sale too! Awesome place.

 

[T911UK]

The Porsche network is interlinked, if you have asked at one dealer and they say no stock then no need to go further.

As you say, rebuilding a pump cant be rocket science

 

[hughdixon]

Thanks for the responses - as you say I cannot see that any 964's or 993's with a failed pump would become scrap/ parts cars, hopefully only a matter of time before Porsche supply new units again.
In the mean time, I need to look for repairers - mcgc0, I am not familiar with Tore Bergville being new to the club and Porsche ownership, can you enlighten me please
Thanks

 

[T911UK]

https://www.bergvillfx.com/

 

[mcgc0]

I am not familiar with Tore Bergville being new to the club and Porsche ownership, can you enlighten me please
Thanks

HVAC or CCU queries or issues, then Tore's your man (among other things). However, he's also a diagnostics whizzo and maybe firing a quick email to him with your 'fault' description might be something he recognises from previous diagnostics coding. Have you had your specialst plug in a diagnostics reader yet? - if not get one done while you are there (i.e. you with the technician going through the response codes).

 

[brian williams]

Have a look at cmsporsche.co.uk they may know of a pump for sale. They are based at Telford.

 

[hughdixon]

Thanks Brian, I gave them a call, they couldn't help. Looks like its a case of source one from Europe/USA or wait and see if Porsche start supplying again.

 

[hughdixon]

thanks for the information, I will try him. The fault is a mechanical one within the pump - to start with the pump was leaking fluid which was resolved, however it would appear a valve in the pump is not working correctly as whilst the unit will pump some fluid, it is insufficient to reach the required pressure. I suspect it will be a case of a replacement unit when available.

 

[mcgc0]

This is where if I had a spare one I would strip it down on the bench and establish what the problem is with the pump valve itself. Bit of an opportunity there for someone with time on their hands me thinks.

 

[hughdixon]

you are right and this is what I will be doing. the problem is sourcing replacement parts as Porsche do not supply any saying the pump is not a serviceable item. Watch this space for an update !

 

[mcgc0]

Excellent, I can feel a specialst machinist's job in the making

I wonder if anyone else has had similar issues.

 

[brian williams]

Hugh, on EBay I input the part number you are quoting and it brought up one in Canada! About £300 plus postage of £79. Check it out. Also input Porsche 964 brake booster pump and found 2 with part no. 96435505352. Both in USA. Good luck.

 

[colin129]

Hugh, on EBay I input the part number you are quoting and it brought up one in Canada! About £300 plus postage of £79. Check it out. Also input Porsche 964 brake booster pump and found 2 with part no. 96435505352. Both in USA. Good luck.

The thing is, if you are replacing a 20 year old part with a 20 year old part, how long is it going to last?

 

[hughdixon]

Thanks for the info. I have sourced one in Germany which should be winging its way to me as I type. Yes I was hesitant about replacing with a second hand unit for obvious reasons, however the biggest issue appears to be leaking seals inside which my garage has managed to solve with a replacement seal. Given Porsche will not give any indication when they will remanufacture replacement pumps, I reasoned its worth the risk for the 400 Euros it has cost. Time will tell I guess.

 

[Ray]

Thanks for the info. I have sourced one in Germany which should be winging its way to me as I type. Yes I was hesitant about replacing with a second hand unit for obvious reasons, however the biggest issue appears to be leaking seals inside which my garage has managed to solve with a replacement seal. Given Porsche will not give any indication when they will remanufacture replacement pumps, I reasoned its worth the risk for the 400 Euros it has cost. Time will tell I guess.

You will always have a spare or an item that you could sell on at a later date. So I think it is not money wasted, think of it as an investment for the future, either yours or some other persons.

Ray