Johnny G Pipe

Found a lagoon of brake fluid in the front luggage comp this evening - its coming out of the pump somewhere, I think probably the switch. Horrid stuff that it is..

Suspicious, and wondering, is this connected with the recent brake fluid change I had done? (last Month) or just bad luck?

Anyone suggest some UK available stuff that I should use to clean up the fluid to save the paint?

I'm off to poke around with a torch - sorry flashlight. Prospect of trailering the car to the independent specialist 100 miles away not filling me with much xmas cheer right now!

WilsonAnderson

Johny G Pipe,

You may want to check the rubber line that runs from the resevoir to the ABS pump in the front of the trunk. If the relay failed, then the pump ran full time and overheated. Mine did this 3 weeks ago. The rubber line melted inside the pump and caused a leak. The pump itself is also ruined. ($1779.00 US- Aftermarket)

If this resembles your predictament, be very, very cautious moving the vehicle let alone driving it as I believe total brake failure due to lack of pressure WILL occur. I caught mine before that happened, but the pump only ran about an hour. Only an hour you say... well the pump got hot enough to cause steam to rise and I think I even got a good buzz going inhaling the vapors. Freaky.

I hope you are lucky, and my situation is not repeating itself for your enjoyment.
This will be the second pump I have replaced in two and a half years.

Take care, do have those brakes checked out!

Wilson

Adrian

Johnny,
Bi-carbonate of soda (baking powder). It might fiz at bit, but it absorbs the fluid.
Why is the system leaking? In my opinion might be just bad luck. Trace the source of the leak first before you panic.
Brake fluid can run down from the reservoir. There is a little cover over the return lines. Remove the cover and check these lines as well as the the output line heading forward.
I echo Wilsons sentiments and advise that you do not drive the car.
Ciao,
Adrian.

Johnny G Pipe

Good evening Wilson and Adrian, thanks for your help.

I drove the car for 20 minutes or so only, after I found the leak - its lucky I have no spare wheel, I would have not noticed for a while otherwise.

The fluid is leaking out the bottom of the switch (from the green anodised barrel in other words), about 5 drips a minute.

I take it (from similar pictures in Adrian's book) that the switch insert wire is meant to be at a jaunty angle..(sorry about the poor pic, hard to get in there with a cameraphone)

Has my wrench done something wrong?

Turbohead

Johnny,
Probably not a coincidence.
If your car is a C-4 or turbo, check to make sure the bleeder valve on the booster accumilator( EGG Shaaped Tank) is tght. I Don't know about baking soda, but if Adrian said so it is probably right. I would wash it with soapy water and wipe and dry it well, since the fluid is very caustic.
Good luck
Elliot

Adrian

Johnny,
It is very hard to accuse people of making mistakes unless you were watching them. There is a seal between the switch and pump and it has failed andbrake fluid has entered the switch.
This is an age issue and a normal failure mode, albeit not a common one.
The brake fluid enters the switch body (not good) and leaks out from the switch section.
This means you should replace the switch and seal, and get the C4 back into a safe driving condition.
Don't forget there is 2600PSI plus in this system, that drip rate you mention will become a flood real quick and you will have no brakes.
Ciao,
Adrian.

Johnny G Pipe

Cool, Adrian, thanks for breaking it down. That makes sense. Doen't sound like the fluid change involves the pump or switch in any way, although I wonder if the change from old to new fluid precipitated the final stage of the seal failure?

I'll get on to it. Going to look into renting a car trailer for the day. Such a shame: today is crisp and sunny, a perfect Porsche day.

WilsonAnderson

Johnny,

My apologies, but that picture is EXACTLY what happened with the first ABS pump of mine.

The o-ring failed. The fluid leaked out slowly, then faster drips, then a slow stream, ending in a glorious puddle of paint destroying fluid in my trunk!

When it occured the warning lights for PDAS and ABS went off, the buzzer buzzed, and the brakes worked like they were greased the rotors!

Take care,
Wilson

Indycam

Hiya Johnny G Pipe
My first pump failed right after a fluid change , hard to know if it was the cause .
You can drive the car in 1st gear at near zero mph or kph and use the E brake .
Flush away all the leaked brake fluid asap , it eats paint . Simple green and lots of water .

The pump has a weep hole from the shaft seal . If you use a small mirror you can see it . If the fluid is leaking from the weep hole , find another pump . The shaft seal is nla .

Patrick L

When I went to local OPC for brake fluid change last time, the technician told me that fluid change may sometimes result in system leak due to sudden pressure change in the system, especially in older cars like 964, although quite rare. They told me that just because they don't want to be responsible if there is any leak after fluid change.

Johnny G Pipe

I thinks its a pretty big coincidence otherwise. Patrick L, I think you confirmed my suspicions. Interesting, and no-one's fault.

I drove our track car home from the track with no middle pedal at all last year. You can stay remarkably safe by keeping huge distances from everything and keeping the speed right down, using the engine braking.

My chap suggests that it can be driven with pump unplugged, with brakes firm but useable..I suspect a few here will disagree!

What is simple green made of? Is it a degreaser?

Sten

Johnny, you have a PM

Indycam

http://consumer.simplegreen.com/index.php

"What are the ingredients in Simple Green?
Simple Green is a blend of water, surfactant (surface-active) agents, wetting agents, emulsifiers, color and scent. Surfactant agents lift grease and oil up off of the surface, wetting agents help Simple Green penetrate soils, and emulsifiers put those soils into solution so that they can be washed away."

"What is the fragrance in Simple Green?
Simple Green is scented with synthetic sassafras - a clean, licorice-type herbal scent.

"the technician told me that fluid change may sometimes result in system leak"
I was told the same thing .

Adrian

Sorry Patrick, but what you have been told is absolute nonsense. The only way during a fluid change that the seals can be damaged is if they use a vacuum to extract the fluid. I have seen this done and pressure seals do not like vacuums.
If the job is done properly there can be no sudden pressure change.
The system pressure is bled off by pumping the brake pedal.
With an accumulator controlled pressure it is almost impossible to even create a sudden pressure change let alone damage the seals. I have worked with accumulator pressure systems all my life and never seen such things as long as the bleed down procedures are even slightly met. Not even cracking a line at full pressure would damage a seal.
I strongly advise anyone who is receiving advice that you can drive a C4 around without brake boost to ignore it. If you have an accident with a failed brake system you are going to be in an awful lot of trouble.
Ciao,
Adrian.

PS: This is not the first and it will not be the last that the braking issue on the C4 comes up. Unfortunately very few of you were 964 owners when this first came up. It got very heated and threats were even made. However after a group of us in C2s and C4s went out, disabled our brake systems (under controlled conditions, I used a runway) and proved how dangerous this situation really was things calmed down for a while.
The results are/were in the archives. One Turbo owner was not strong enough to operate the brake pedal for the eight times you have using accumulator pressure only (80 bar) and he hit his garage door.
Another guy flew through a set of traffic lights after ignoring the warning. I do not think it is very smart risking the lives of others for the cost of a flatbed.
Oh by the way, the cost of destroying your parking brake pads and the rear rotors is also a tad more expensive than a flat bed, if they are in good enough condition in the first place.
Driving around in first gear is not real smart either. There are financial costs involved in owning a 964 and killing yourself or somebody else just to try and save a few bucks is not very responsible in my opinion.

Dwane

I am having the EXACT same problem. Would anyone have the part# for this item?