D_Schultz

Yep...son of a gun - my PDAS pump stopped working & brake pedal went hard in the middle of traffic. (For Adrian's database: no, I had not had any previous warning lights, the pump DID seem to run a bit longer than usual on startup (perhaps 30 seconds total running), and I DID find a small amount of leakage where the pressure switch screws into the pump body (but only a few drops & none since). It certainly woke me up when I suddenly had no boost & had to really stand on the pedal for decent braking. Based on my location at the time, I was forced to continue on & found that the brakes DO work, but take some serious force to stop quickly.

Just for fun (after having read the huge debate on loss of PDAS pump function) I found a nice deserted stretch of pavement on the way home today & tried 20 or so stops from 50 to zero. No noticeable brake fade, but my left leg got a real workout! Did not find any additional fluid loss after the test either.

Now...since I have NO intention of continuing to drive like this - where is the best source for a replacement pump and/or switch? Will troubleshoot in the coming weekend to determine the faulty component, but want to have a replacement source in mind before I get that deep. Also - relay's verified OK.

Thanks in advance for any advice!

David S.

'93 964 5spd (currently garaged in favor of my Z3).

gjvander

Definitely replace the pressure switch first before you go off and spend big money on the pump. The switch started leaking on mine. I think I paid $200 for it.

Regards,

Geo

D_Schultz

Thanks for the moral support guys! Still don't have a decent source for the pressure switch though. Best I've found is $275 with no guaranteed date of delivery. All the older tech postings I've read mention purchasing the part for right around $180. Anyone know a source??

Geesh, with my 23 year old 928 I can source almost any part on the car for peanuts compared to most anything on the 964

ACFOUR

You will need to get the Porsche part for this, so the best price will probably be from Sunset Porsche or Pelican Parts. I had the opportunity to have mine replaced a little over a year ago and the price was approximately $2,000. I believe Jason A reported that they are about $2,600 now.

When my pump went I was leaving a shopping center. I was able to drive home (about 10 miles) but took back roads and tried to minimize any abrupt stops. It took a lot of prssure but was not unreasonable. An emergency stop would have been interesting though. Glad you had no problems getting home.

Wachuko

Had a similar situation June 8, 2000.

I was using the car and had to make a sudden stop
at a speed bump. The ABS came to play. Since it was the first time I had sense the system in action I decided to give it another try. It worked flawlessly. Close to my house I made a normal stop and to my surprise the brake pedal would not respond. I had to push it extremly hard to make the car stop.

The problem was solved by: Pressure Sensor replaced(US$247.55 - Part # 964-606-904-00), Relay replaced (US$33.81 Part # 964-615-135-00), Rubber O-Ring replaced(US$4.99 Part # 999-707-094-40). Labor US$147.90 Minus PCA discount.

Try Sunset Imports/Porsche for the parts (did not know about them at the time)... they should have a good price. - http://sunset.porschedealer.com/