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-   -   PDAS/ABS pump - not the best day!! (https://rennlist.com/forums/964-forum/569793-pdas-abs-pump-not-the-best-day.html)

Computamedic 05-23-2010 06:36 AM

PDAS/ABS pump - not the best day!!
 
Having just wasted an hour or so going to the PCGB Boxster and Beyond event, only to find NO Register parking whatsoever and what parking there was was on a lousy gravel area with no segregation for Porsche cars or Register gathering points. I just left in disgust I'm afraid and I'll resign my Register Secretary post because of it.

Of even more importance was that the moment I got home I get the PDAS/ABS alarm and a very obvious solid brake pedal. Classic symptoms of a failed pressure pump and, sure enough, the pump was red hot, fluid dripping from under it (and from around the plastic inlet pipe on the top). The pump had run normally when I left home and had stopped within 30 secs and the drive home was fine. It was only when I went to subsequently put the car away did I get the alarm.

For the moment I've disconnected the pump and the pressure switch to let things cool down but my fear is that the pump may be damaged beyond repair. Has anyone any thoughts??

I remember reading something that Adrian Streather wrote some years ago about the overheating pump causes the plastic inlet pipe to melt and subsequently leak. It's possible that THAT is the problem - but there must be an underlying problem to let the pump overheat in the first place. The common culprit is a failed pressure switch and I would be thankful if that were the situation. I really, really don't want to have to spend mega ££££ on a new pump.

Regards

Dave

tgage 05-23-2010 09:57 AM

I had a similar issue on my C4 years ago. Just a guess, but the sensor into the pump (may be the green cylinder?) was no longer measuring the pressure correctly, which forces the pump to stay on. The result is the pump fails and the line going from the reservoir to the pump melts at the pump. I tried manufacturing a replacement connector but they all leaked and was able to find one at a junk yard (20th street auto in Phoenix). I still have the extra line if you need it, but used the end piece that goes into the pump. As far as the pump goes, you can test it by applying voltage to it and at least know if you need to replace it or just the pressure sender.

tom

screamingflat6 05-23-2010 02:28 PM

Dave,

Sten on here AKA baz told me a mk2 ford granada has a similar pump, I will pm him later tonight.
Remember, I was having the pdsa lights and brake warning problems myself and it was a worry.
My car just needed a relay and a bleed in the end, but it took me to go to a specialist in the end to resolve this as it was a real headache to me.
I bought dizzy caps rotor arms and was on the way for ht leads, but I thought after a mate of mine had allsorts of electrical gremlins fixed on his early 928, I would give Chris sanderson of loe bank motors bury a go and he fixed it within three hours.
I hope you get it sorted as I know its a total pain in the ass when things go wrong and the frustration eats away at you, but within the forum I am sure someone can point you in the direction of repair or a similar replacement unit.

Gaz,

vasculardoc 05-24-2010 08:43 AM

Also check relay 51 - it can get stuck on if it is a bit dodgy and it leaves the pump running despite the pressure being high enough. Was happening with mine last week. Also the O-ring between the pressure sensor (green cylinder) and the body of the pump can fail and give you a boot full of brake fluid - Messy ++++.


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