Braking Bad

[tony_ack 0]

I've got a few issues with the brakes on the car - the issues have been annoying me for a while, but seem to have got worse recently.

 

I've swapped the fronts to 288mm discs a couple of years ago, and the car was lowered 30mm at about the same time, but otherwise the brakes and suspension are standard.

 

The first problem was that the rear brakes were making a loud whining/groaning noise when reversing - it's been like that for a couple of years now, but recently it's started to do it a lot more, including when I'm driving forwards and braking/coming to a stop.

 

Also, the wheels at the back are constantly covered in brake dust, whereas the fronts rarely are. There really doesn't seem to be a lot of braking force - the car does stop if you slam on the brakes, but it doesn't really feel sharp at all. I adjusted the bias valve last year, which improved things a little, but it seems to have got a lot worse again now.

 

In the last few weeks, after first starting the car and moving off, the first time I brake at the end of the road (on a slight downward slant), the pedal goes almost to the floor. After that initial scare, the brakes firm up quite a bit, and were fine, although today it seems to be doing it while I'm driving normally as well. The first time I push the pedal, there's very little resistance, but if I release and brake again, the pedal is a lot firmer.

 

The fluid was changed about 18 months ago at the same time as it had some new front to back brake lines. The garage spent a lot of time bleeding the system to get the pedal feel back, including a lot of time on the ABS pump. The bias valve was replaced about 5 years ago, and seemed to move okay the last time I adjusted it.

 

Any ideas at all?? It's getting pretty dangerous now!