S4s Brakes

[davevr6car]

My 95 S4s brakes are driving me mad.

Took my car out for a run today and the brakes are all over the place.

When I apply the brakes, sometimes the car will pull to the left and then to the right, other times there seems to be no brakes at all, and then the brakes will be working ok.

It is very unnerving when driving in damp contitions and at speed, as I seem to be trying the brakes all the time when coming into a corner thinking that the brakes are not going to work.

All the pads, discs and brake fluid level are all ok. The ABS warning light has never come on while driving.

Can anyone help as I do not what to drive my S4s thinking I'm going to crash it

[esprits4de]

Any clicking noises from the relays or ABS valves when breaking ?

Sounds like a shortcircuit !

Could also be, this is a long shot, that your PU bushes are worn, but that would only explain directional misbehavior.

[fflyingdog]

My 95 S4s brakes are driving me mad.

Took my car out for a run today and the brakes are all over the place.

When I apply the brakes, sometimes the car will pull to the left and then to the right, other times there seems to be no brakes at all, and then the brakes will be working ok.

It is very unnerving when driving in damp contitions and at speed, as I seem to be trying the brakes all the time when coming into a corner thinking that the brakes are not going to work.

All the pads, discs and brake fluid level are all ok. The ABS warning light has never come on while driving.

Can anyone help as I do not what to drive my S4s thinking I'm going to crash it

Hi Dave

Stupid qustion but have you checked your tyre pressures ?Make sure they are all spot on as this could cause the car to pull to one side or the other.also check you have no fluid leaks ?

As for your brake failure i have never come across the system failing completely, you say that your abs syetem is not faulting(your abs fail tell tale light does work doesnt it?),it would seem like your pump is not running to top up your braking system pressure, this would indicate our old friend the pressure switch is bad.even with a bad pressure switch the system should still work in a "fail safe" type mode to enable you to stop the car ,this would also throw up an abs fail light either flashing or steady.

Hope this is of some help.

Cheers

Nick S4s

[davevr6car]

Hi Dave

Stupid qustion but have you checked your tyre pressures ?Make sure they are all spot on as this could cause the car to pull to one side or the other.also check you have no fluid leaks ?

As for your brake failure i have never come across the system failing completely, you say that your abs syetem is not faulting(your abs fail tell tale light does work doesnt it?),it would seem like your pump is not running to top up your braking system pressure, this would indicate our old friend the pressure switch is bad.even with a bad pressure switch the system should still work in a "fail safe" type mode to enable you to stop the car ,this would also throw up an abs fail light either flashing or steady.

Hope this is of some help.

Cheers

Nick S4s

Cheers Nick for your Reply,

I may have mislead you in my previous entry, but the brakes have never completely failed, but on occasions when i have applied the brakes the pedal seems to have little resistance and little stopping power for about 3 or 4 seconds which feels like a long time, by then I would have apply the brakes again.

If I keep pressure on the brake pedal and turn on the ignition I can here the servo's clicking and the pedal feel hardens.

I then turned off the ignition and depressed the pedal 40 times depressurising the system, turned on the ignition and the air pump ran for about 30 seconds. It seems that the air pump is working ok.

Has anyone one tried installing a different braking system, like a vacuum servo assisted one without the abs?

cheers

Dave

[esprits4de]

There was a post om late GT3's having the V8 system fitted, but after I had asked for confirmation on that, I didn't anything anymore.

I was intending to something like that in the future if I do not get the system settled with the new pressureswitch.

Supposedly the ECU is the problem here .

I will have to look for that thread....