Confusing brake problem

**owen_999** · 9th March 2013, 18:40

As people have probably seen I've been having strange problems with my car.

Well yet again the brakes have come back to haunt me. Driving along today and I put the brakes on and the pedal felt as if it sort of just dropped away from my foot and the brakes didn't go on. Old handbrake is earning its use.

Vauxhall have had it back and say there is no fault codes on the car but I'm just wondering if it could be something mechanical like the master cylinder or even an ecu problem tricking the abs. I just don't know what it could be.

**STICKY3.2** · 9th March 2013, 18:49

Is this an intermittent fault or is it there all the time?

**owen_999** · 9th March 2013, 18:58

It's happened twice to me now and its just completely random. The first time was under heavy breaking and this time I was just lightly touching to pull up for a junction. It seems completely random to me. There seems to be no specific circumstances I can think of that causes it.

**STICKY3.2** · 9th March 2013, 19:17

I would guess that the master cylinder is failing. A bit worrying for you as you don't know what brakes you are going to get when you press the pedal. One test for master cylinder is put your foot on the brake and keep constant pressure if it creeps all the way to the floor the master cylinder is probably faulty

**owen_999** · 9th March 2013, 19:21

Yep that happens. But is that not due to the double diaphragm or do you mean when the engine is off?

**Ben50n** · 9th March 2013, 19:24

With the engine switched off, the pedal should go hard after a couple of pumps. Then try pressing hard on it to see if the pedal sinks to the ground. If it sinks then there is a leak and I would say its the master cylinder.

**owen_999** · 9th March 2013, 19:29

Well there is no visual signs of a leak. Have just pumped the pedal to make it hard and with constant pressure it creeps to about half way the stops. If I apply a bit more pressure it is pretty solid. I'm completely stumped on this :-/ is anybody around the Southampton area that has a bit more knowledge an experience about tomorrow to help me? Just don't want to be driving such a dodgy car.

**jeff workshop** · 9th March 2013, 19:42

hi it sounds like your master cylinder is letting fluid passed the seals inside which will show no signs of a leak and only give you half your brakes either front or rear.

**owen_999** · 9th March 2013, 19:44

That's what I think but my vaux garage just say to me well the computer says its fine so there is nothing wrong with it. Might just give the car back and say not fit for purpose or safe on te road.

**Ben50n** · 9th March 2013, 19:46

I do not know how it would show up on the computer? Its a hydraulic seal problem not an ABS problem.

Take it back or get them to sign a statement that if you have an accident due to brake failuer, then they will be totally responsible.