Now then guys n gals, help needed:

Has anyone experienced soft brake pedal and deteriorating brake performance?

I love the car and keep it in tip top condition however after a good afternoon session over the trough of bowland, my brakes went from as sharp as, to soft and scary. I put it down to warping the disks or perhaps boiling the fluid so it went in to the dealer to have the fluid changed, fix a sticking calliper and I put new grouved/ vented disks with yellow racing pads on all round. No change! The mechanic said the brakes feel like they should but I know they don't feel like they used to or should.

Is this a master cillinder problem? or if someone has experienced this lemme know what u did pls

Cheers

Scott

If you pump the pedal with the engine off / cold, then hold the brake pedal down, then start the car, does the pedal travel down slightly? It should, that means the servo / brake booster is contributing.

Sounds like a master cylinder problem though (assuming the brakes have been bled properly after the fluid change). Are there any leaks driblling down the brake pedal or damp carpets or visible leaks around the master cylinder? Any paint blistering on the servo?

could be air in the abs pump. Normal bleeding will not remove it, needs to be pressure bled or use VAG COM to run the ABS pump

HOw do you do it in vag com and do you need to bleed while doing it?

If you pump the pedal with the engine off / cold, then hold the brake pedal down, then start the car, does the pedal travel down slightly? It should, that means the servo / brake booster is contributing.

Sounds like a master cylinder problem though (assuming the brakes have been bled properly after the fluid change). Are there any leaks driblling down the brake pedal or damp carpets or visible leaks around the master cylinder? Any paint blistering on the servo?

If you pump the pedal with the engine off / cold, then hold the brake pedal down, then start the car, does the pedal travel down slightly? It should, that means the servo / brake booster is contributing.

Sounds like a master cylinder problem though (assuming the brakes have been bled properly after the fluid change). Are there any leaks driblling down the brake pedal or damp carpets or visible leaks around the master cylinder? Any paint blistering on the servo?

Thanks - I'll start lookin for leaks and try the servo thing.

I asked them to bleed & change the fluid. It looked like they were forcing or drawing the fluid through with pipes and a machine of sorts. Can't say I have ever bled brakes that way so I thought it must be to do with the ABS.

What's a VAG COM? I guess it's something I won't be doing!

There are bleed nipples on the master cylinder, so you could try bleeding that first.

VAG Com (now called VCDS) information is here:

Ross-Tech

Brake bleeding procedure here:

Brake Bleeding