Apologies if this is in the wrong section.

 

We have a Fabia MK2 1.6 2012.

 

We upgraded the brakes to 312mm by changing the carriers and the alike.

 

I've done this multiple times on the previous platform.

 

We've bled the brakes and all is well when the engine is off, pedal is nice and hard. Turn the engine on the pedal goes straight to the floor and they're no brakes whatsoever?

 

Any clues? We've bled all 4 calipers now and used a pressure bleeder as well?

 

Thanks!

I think there is a procedure to bleed the abs unit that requires VCDS/diagnostics to run a special purge sequence.

(As usual I may be wrong)

Other thing I read is some vag flexi hoses should not be clamped as it can damage them and they then baloon under pressure.

There is but if it was air in the system the pedal would be spongy and firming up with every application. Raymonndo described a complete "lack of pedal". That would suggest to me sth at the servo/master cylinder or slave cylinder not working.

I assume there are not leaks in the system you can see?

Bleeding brakes using two man "press the pedal mate" method is alleged to potentially damaging master/slave cylinder.

The thing you do not want is the ABS pump to go dry while you were ding the Brake System changes.

Master cylinder changed no difference :(.

Possibly damaged the pipes then? We did clamp :(.

Is it still the same, no pedal when you switch the car on? Did you do the VCDS scan for error codes?

Other things are slave cylinder and electronic pressure bypass valve.

A member here under a name of xman is/was a pro tech and he is very capable of helping out much more than I am.

A member here under a name of xman is/was a pro tech and he is very capable of helping out much more than I am.

Woah there!! Where on earth did you get that idea?? I think you mean estateman.

Just a thought- if you disconnect the plug to the abs unit, and then started the car and test it. To check that the abs unit is not releasing pressure as it does if its activated.

Edited 21 April, 201511 yr by xman

One of you lol

With vcds, abs 03, basic settings 04, group 01, go...

this will make the abs motor run, i forget how long it runs for now, but its about 30 seconds or so, using a pressure bleeder at the same time, this should purge any trapped air from the valve blocks, hth

Thanks all! The mechanic has also tried bleeding the ABS.

All I can think is lines? :(.

No pedal means no pressure so unless lines are broken and let the fluid out I cannot see how it would manifest itself in no pedal, unless earlier mentioned pressure diverter valve is to blame. Two more things to check, slave cylinder and servo.

I'd start from checking for faults on VCDS first before any more money is spent.

Nothing on VCDS D:

Try logging brake system pressures, I think there are two or three measuring blocks you could monitor, perhaps this wouls shed some light before you start replacing more parts? Have you done the ABS pump bleeding procedure yet?

Any News?