Brakes

Multiskilled · Post by **Multiskilled** » 04 Sep 2020, 11:40

Hi everyone
I have a major brake issue which I've been trying to sort out but getting nowhere.
When driving normally when I go to brake the pedal is hard and like bouncing as if the ABS is on but I have no warning lights on, after a second or two or a couple of pumps on the pedal they will work ok ish , this happens 95% of the time, at speeds at under 20mph they are mostly ok.
If I drive it like I just stole it and red line it through the gears the abs light will come on but the brakes will work fine whilst the light is on, but the engine seems to drop rpm instantly when you take your foot of the gas to change gear causing a harsh jolt (Stick shift), also cruise control was surging but has now packed up whether they are linked i don't know.

Thanks in advance

duke1 · Post by **duke1** » 04 Sep 2020, 12:03

hi id check servo hoses for leakage first and around all the brake master cylinder etc but id bet theres a leak on or around the brake servo,good luck

Multiskilled · Post by **Multiskilled** » 04 Sep 2020, 13:04

Yeah I did wonder and have looked but I would of thought that it wouldn't of made any difference when the abs light comes on if its a leak

Cookeh · Post by **Cookeh** » 04 Sep 2020, 13:58

Sounds like one of two things to me. A bad ABS module - the repair of which is both quick and easy; orthe insulation on the wires going from the ABS module to the ABS pump have degrade and are shorting out. This will trigger your ABS without triggering a light.

Check the wiring from under the black cap of the ABS pump to the module. I will be very surprised if it isn't cracked or brittle.

Multiskilled · Post by **Multiskilled** » 05 Sep 2020, 07:02

Checked all the wiring all seems pretty solid for a 20 year old car, can I unplug the abs module and go for a drive to test it or will I have no brakes

Cookeh · Post by **Cookeh** » 05 Sep 2020, 07:25

You'll have brakes, just no functioning ABS (which is your current issue anyway!). Not sure how useful this test would be though, as without the module in place there is nothing to test, and whilst it will throw an abs code it might not be the one causing your problem.

Multiskilled · Post by **Multiskilled** » 05 Sep 2020, 07:48

I was thinking that if I unplugged the abs and the brakes work fine it would indicate a abs problem and that everything else was OK, apart from changing the module there is not really anything thing else I haven't checked
I have got functioning abs the problem is its working pretty much all the time

Post by **abscate** » 05 Sep 2020, 16:14

Try torquing the front axle bolts to spec, if they get loose they trigger ABS

Post by **scot850** » 05 Sep 2020, 19:59

If you are getting a hard peddle it is more likely you are getting no help from the booster. It may not be the booster but a failed pipe leeding to the front of the booster or the one way valve has failed. It is a plastic piece fitted in at the front of the booster which connects to the pipe to the intake manifold. The part is difficult to access depending on which version of the car you have. If you remove it, you should only be able to blow through it one way. Fairly cheap part to replace or pull from a junkyard to test this.

Now the ABS chatter is more like the ABS module or a bad wheel sensor signal (either a bad wire near the wheels or connector or a broken or clogged reluctor ring on the axle.

It could be you have 2 separate issues rather than one.

Neil.

Multiskilled · Post by **Multiskilled** » 06 Sep 2020, 03:38

This is what I've done for now I've had this problem for about 3 months and just glad to have brakes again, but I've disconnected the abs motor wire just below the module harness and the brakes are working fine although I now have a abs light on which I'm willing to trade that for working brakes. It gives me 6 months to sort it out before its next mot / inspection.
I don't suppose there is anyway I can turn the abs off without setting off the warning light.

Thank you all so much for your help very much appreciated