Bleeding brake system!

[day]

Hi All

I am new to this forum and wonder if anyone can help out!
I have a golf mk4 1.9 gttdi

I've just had to replace my back brake discs and pads - Although never done it before thought i would give it a go.

Changed the discs and pads fine and then it came to trying to bleed the system. I bought one of those one way valve kit to bleed it and i have done all 4 corners but something is still not right.

The braking is still really really spongy and the light on my dashboard telling me to check brakepads is still on. i bought new brake fluid and everything and now i just dont know what else to do.

Is it a case of just bleeding it again? am i doing something wrong? please can anyway help!!!!

[Wasptuning]

Bleed again, you still have airbubbles.

[Col]

For some reason the VAG systems seem to be very sensitive to the old fashioned pedal pumping method i.e. it doesn't work.

If you do have another go and it still doesn't work, try a pressure bleeder like the Gunsons Easybleed (from Halfords).

Hopefully someone like Crasher or A8tech will be along to offer their wealth of experience on this.

[cavanagh81]

hi im having same problem having just fitted abs pump, ive even pressure bled system using easy bleed kit and have reverse bled using electric pump and have bled bleed screws on master cylinder but still got soft spongy brakes. When engine is not running brakes pump up hard but when started and servo kicks in go soft again, ive now bled system 10 times and am sure there no air in system, has anybody got any more ideas , Thanks.

[Nutty]

Are you sure you have adjusted the rear brakes correctly ? leaving the pad to far away from the disc will give you a spongy pedal, feeling like there is air in there, it may just be the piston having to travel to far in order to apply the pad to the disc..

[Borab0y]

dont forget the new pads have to bed in aswell, maybe causing some of it.

[Col]

hi im having same problem having just fitted abs pump, ive even pressure bled system using easy bleed kit and have reverse bled using electric pump and have bled bleed screws on master cylinder but still got soft spongy brakes. When engine is not running brakes pump up hard but when started and servo kicks in go soft again, ive now bled system 10 times and am sure there no air in system, has anybody got any more ideas , Thanks.

If you have changed the abs pump, you need to set it so that it goes into its bleed mode. To do this you need vagcom or similar.

Look in the vagcom subforum for details of either setting yourself up with it or to find someone with who can help.

[cavanagh81]

hi thanks for all feedback, i have vag-com software and data cable is it possible to do with this and any idea how ?

[NickPicks]

I hate bleeding brakes. It's the one thing I'd rather pay someone else to do. One thing I have learnt though is that if the car has a load proportioning valve on the rear axle, it needs holding in the open (heavy car) position while you bleed the rear brakes. Otherwise it reduces the rear brake pressure and you don't get the air out.

One question: Why did you have to bleed the brakes when changing the pads and discs? I've never had to break the hydraulic circuit when changing pads or discs. Or was it a "While I'm there, I'll replace the brake fluid too"?

[mluton]

I agree, it one of the jobs I pay to have done.

I've never bled the system on changing brake pads, just take the lid of the reseviour.