Hi I have a 2002 vrs and have changed the rear driers side brake hose and caliper today when I have come to bleed the caliper it bleeds ok then the pedel goes hard but when you start the engine the pedel goes spongy anyone have any ideas whT could be wrong thankS

That's normal. The pedal will sink when the engine starts as the servo starts to work. It runs on the vacuum generated by the engine.

But the brakes are not working as normal I have to put the pedal to the floor for it to work. I know it loosens off when you start the engine but the pedel is still spongy Could there be air trapped in one of the other wheels? Thanks

There's a good chance that now you've run up and driven the car the airs shifted about rather than being solely in the caliper you worked on. May well be a case that you now need to fully bleed the system, could be easier to just take it and have a fluid change done, should be able to find somewhere that does this for a reasonable price.

Did you allow the level to drop in the reservoir?

How did you bleed the system?

How did you bleed it?? If it was pump the pedal method then you might meen a new master cylinder. Only way to bleed octy's is to use a pressure bleeder

Even without reversing the master cylinder seals, if you pump the pedal you can get trapped air in the ABS block. The only ways to bleed an Octy brake system are pressure bleed at no more than 1bar or vacumn bleed, and use VDCS at the same time to bleed the ABS block.

Best case, your brakes need bleeding properly; worst case you really do need a new master cylinder.

Hi I think this is what has happened I have air trapped inside the ABS block its been in my local garage and they have bled all 4 calipers and the brakes are much better but there still not right. Can anyone give me a step by step guide how to blled the ABS block? Thanks

You'll need to bleed the master cylinder as well.

Usually you only need to bleed the ABS pump if you let the fluid in the master cylinder go too low. Vagcom or VCDS are needed to bleed the ABS pump.

Edited 30 September, 201114 yr by pauldazzle

Check my thread in maintenance and performance section.

Reversing the master cylinder seals is actually a myth, what happens is air gets trapped in the EDL line in the ABS control unit. This must be bled with sub 1 bar pressure (the pedal goes way over that) so the EDL line remains closed and air stays in it and the pedal goes crap. Low pressure bleed should do it, the ABS pressure bleed as performed by VCDS actually opens the EDL valve, thats why it only bleeds out the front circuits not the rear.

I have got vagcom but its just a lite version can i use this to do it or will i need to buy it or would it be easier to take it to skoda? Or is there another way to do it?

Thanks

Iv got a copy of vag com for the weekend now. Am I right to think that I need to activate the abs pump then bleed the system through the 4 wheels using a gunzen ezbleed And can you tell me what wheel first to last thanks

VAG COM will guide you, as said the ABS bleed only works the front wheels as the EDL only operates through the front.

Thanks is it the screen where it says activate abs pump then next screen says something about brake pedel? Sorry for all the questions I'm just at work and have not had time to look at it properly.

Pretty sure there is a guide on how to do it on ross-tech website.

Thanks for everyones help i tried bleeding through vag com and was still the same. so on the off chance there was air stuck in the master cylinder i bled that to and on the nipple closest to the bulk head low and behold air then fluid. the only explation i can work out for this is the air has traveled up through the system cos the resevior was never empty. but all sorted now.

Thats an odd one, glad its sorted now though.

Thanks for everyones help i tried bleeding through vag com and was still the same. so on the off chance there was air stuck in the master cylinder i bled that to and on the nipple closest to the bulk head low and behold air then fluid. the only explation i can work out for this is the air has traveled up through the system cos the resevior was never empty. but all sorted now.

Thanks from me too, I had the exact same problem as chris, TECH1e is right, I used a pressure bleeder as well and it worked great to get the air out of the master cylinder.