19 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHWheels Locked Up 1999 C4
Reported or suspected cause
eventually
Reported cause
No successful repair reported for this finding.
1
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0
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0
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Reported cause · Original poster
The problem was eventually solved by having the ABS electronics repaired.
Leading evidence: 'eventually' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'eventually' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Fill with water' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
The booster was filled with water but that wasn't all; the master cylinder also needs to be replaced.
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Performed · outcome unconfirmed
Both compartments were filled with water, the drivers side enough to slosh around under the brake booster.
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Performed · outcome unconfirmed · Original poster
Rear Bumper Crash Absorption (I installed a 1.25 receiver hitch)
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19 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
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Driving yesterday when the wheels started to lock up on me. I hurried to a side street but could not pull over to the curb as the locked completely. I think it was just the rears. The brake pedal was all the way up and I could not push it down at all. No codes were thrown.
I called AAA to get a tow. As I was waiting for the tow truck to arrive, the brakes started to ease off and I was able to get the car out of the middle of the street. The car is at the shop now but and will get looked at in a day or so.
Any ideas about what could be wrong?
John
Hey John, I've had this problem before... it ended up being a malfunctioning master cylinder. However, if it's just the rear wheels, it could be the parking brake system locking up on you. The parking brake system has drum style brakes on the rear wheels only. Anyway, I would get it to a brake shop immediately.
I just found the following PelicanParts. Describes my problem exactly.
Brakes Locked
Comments and Suggestions:
BadUrbanKarma
Comments:
I had the same problem when I first bought my car used, 14 yrs old. I had to get towed the first time it happened. After that, I just carried a wrench to relieve the pressure at the caliper bleed valve. The problem was eventually solved by having the ABS electronics repaired. I think one of the circuits was causing one of the ABS block valves to activate, restricting normal flow. The Bosch 5.7 ABS electronics are notoriously fragile.
January 31, 2018
Followup from the Pelican Staff:
Thanks for sharing your experience. These type of comments add so much to the Pelican tech community.
- Nick at Pelican Parts
Eringofast
Comments:
Sorry but i dont understands why brake line pressure would be held up after the booster that would cause this? The vacuum in the booster is holding the rod pressure so when I pull the vacuum line at the booster the car frees up.
I'm not trying to be difficult but just trying to understand how the line pressure would cause this.
Could the brake line pressure regulator cause this which is clipped to the side of the ABS control pump?
October 11, 2017
Followup from the Pelican Staff:
A line restriction.
- Nick at Pelican Parts
pacerville
Comments:
This seems to be a common problem, I know of my car and one other where the entire system booster, master cylinder, ABS controller, brake push rod, new front brakes and rotors, bled the brakes, you name it. All 4 brakes lock up. The only way to relieve the pressure is by pulling the brake pedal up by hand. Once the brake fluid is cooled, the brakes are ok, until it warms up again. Any answers?
September 12, 2017
Followup from the Pelican Staff:
I have not seen that issue. Sounds like a faulty master.
- Nick at Pelican Parts
Eringofast
Comments:
Help!
1999 996 the brakes start to come on by them self after about 15min of driving. I've pulled the and fuse same. After this happens the front brake lockup car will not move. I've pulled the vac line to the booster and car will roll again. I've changed booster, master. Any theories?
August 20, 2017
Followup from the Pelican Staff:
You will have to test pressure at the brakes to see what is happening. MOnitor line pressure when issue is present. Then work your way toward the master to see where pressure is being held up.
An alternate method would be to crack lines open to find the source of the hold up.
- Nick at Pelican Parts
You have a choice:
1. Cassette Storage Unit
2. Genuine Porsche CD Changer (no magazine)
3. Rear Bumper Crash Absorption (I installed a 1.25 receiver hitch)
4. Rear License Plate Holder
Seems like I remember a TSB on the 99's about water getting into the brake booster causing it not to return to rest position. If I remember the cure was to replace the booster and install a new drain valve under the booster next to the battery..
Your memory serves you well. I remember the first time I washed my car and just happened to look down into the areas next to the battery. Both compartments were filled with water, the drivers side enough to slosh around under the brake booster. Cleaned out drains and now check them often. It only takes one leaf to block them. The drain valves were redesigned with a split in them to allow water to drain better and all the way down in those compartments, but it is best practice to check them often. It is amazing how much trash and leaves somehow get in there.
My brother's '00 Carrara 4 has this problem. You need to pull the pedal back with your foot or else it will drag. Got a replacement booster that I will install in the next few weeks.
Heard back from the shop today. The cause of my brake trouble is a bad brake booster due to water intrusion. They quoted me $500 for a TRW brake booster but we stopped that nonsense right quick! Ordered the same part from
FCP Euro
for $170. Oh, the brake light switch was also burned out. I'm pleased with the outcome. Not that I wanted this to happen but what can you do?
