C4 Brake issue
#1
Instructor
Thread Starter
C4 Brake issue
Out all day with no problems observed arrived home parked on the drive. Started the car to garage ABS and Diff lights on buzzer kicked in and brake pedal went soft. Checked as much as I can, no leaks visable, levels are fine, pressure pump runs for 35 seconds then off, fuse ok etc. everything seems ok now as brake pressure feels fine but It's off to the workshop later today to see what we can find, Lucky it happened on the drive and not on the road from what I've read in previous posts.
#5
Instructor
Thread Starter
Ignition on pump running but felt more travel than usual in the brake pedal then as I pumped the pedal slowly it lost pressure traveling further on each occasion. With ignition off pumped the pedal which eventually went hard. Next morning following previous checks etc, ignition on, pump ran as normal and pedal feels fine
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#8
IHI KING!
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Join Date: Aug 2001
Location: Nashua, New Hampshire, USA
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In thinking about this more, it reminded me of when my ABS pump failed on my C4, the peddle went soft and it was very hard to stop the car. The cause of the fault was a faulty relay which then stuck in the on position and burned up the pump. You don't want that to happen. It was very expensive to fix back in 1996. I wouldn't want to know today's prices. I would try changing out the ABS relay.
#9
Instructor
Thread Starter
Well following a system check nothing could be found (no codes logged) and we could not recreate the issue. Conducted a full brake bleed, low and behold no lights or buzzer ever since. Went for a spirited drive on Sunday (no traffic, open roads) and the brakes, abs system worked fine.
It still bothers me that it happened in the first place but so far everything seems back to normal?
It still bothers me that it happened in the first place but so far everything seems back to normal?
#10
Nordschleife Master
I dislike brake problems , if there is anything I want to be 100% right , its the brakes .
I hope the problem was a stuck valve or relay and that it will not stick again .
I hope the problem was a stuck valve or relay and that it will not stick again .
#11
#12
Instructor
Thread Starter
#15
Rennlist Member
The lucky end result of similar happening going into T14 at Thunderhill one time. (Wouldn't you know it was one of those "last run" situations where I was really trying.) No, never did find any problem. No, never happened again.