Right then

Pig of a weekend - went for MOT and failed due to o/s/r wheel cylinder popping out as MOT man started brake test.....Anyway MOT man said that it was dangerous to drive but I risked it and managed to get home okay.

Bought new wheel cylinder and fitted it with no problems, however I needed a new Eezibleed kit as my old one seals had all perished before bleeding the brakes.

New Eezibleed kit bought and bled the affected line. Gave it a good run through of new fluid. Tried pedal without servo and seemed fine - turn on engine and pedal really poor going nearly to the floor! So then I think, "No problem, bleed the rest of the system!" Bled all the lines through with plenty of fluid - no air in rest of system. Tried again and un-servo'd fine but engine running - crap pedal......

Okay - must still have air in the system. Repeated the whole process again but still no joy..... Had a run around the block and brakes do bite but right near the bottom of pedal travel. This has really p****d me off as I have spent a day and a half trying to sort this.

What have I done wrong???:confused:

Octy is a 2001 1.9TDi Ambiente, by the way.

If brake testing how did you know wheel cylinder popped it would be covered by the drum?

Are you sure everything is together right? How would the cylinder pop if the drums were on and everything together properly?

Clamp the hose to that wheel and see if the pedal is better. If it is at least you know that's the brake causing the poor pedal. Does seem odd that a cylinder can pop out when all assembled??

I'm no expert, but, there is a set sequence that you should use to bleed the brakes, and I am sure that one of the expert techies will come on and advise you which wheel you have to do in turn, also, do you have ABS, as if you drain the lot, then air can get into this as well, making it hard to bleed.

Maybe this is a stupid question, but you have adjusted the brakes correctly, and got the auto-adjusters holding on?

vag-com has a brake bleeding process which involves running the ABS pump, but I don't think I was very good at following the instructions when I tried it, and was not 100% happy, so I shelled out and let a Skoda dealer have a go.

If as you say the rear wheel cylinder 'popped' during the MOT test and you drove it home afterwards, I would expect that that part of the system had been completely drained of fluid. This would mean that it is likely that there is air in the ABS valve block, which would explain the pedal travel with the engine running (the ABS system doesn't come into play with the ignition off). This will need bleeding with the help of diagnostic equipment (dealer VAS or VCDS).

There are bleed nipples on the master cylinder, you could try these, but if this was the problem it would show up with or without the engine running. With regard to the bleeding order, I always tend to bleed the one furthest away from the master cylinder first.

I believe the clutch is operated using the brake fluid and this portion of the system requires bleeding too. I dont know the bleed point location for this but a search on here should come up with it.

Thanks for all the replies:thumbup:

Just to clarify a few points - when the MOT tester got out and looked after pressing the brakes the o/s/r drum was leaking fluid. It was not until I got home and removed the drum that it revealed that the cylinder had popped out.

So why did this happen when everything is all together?? Well the cylinder (with an alloy body) had started to corrode between the back plate and the cylinder body. The corroding metal had pushed the cylinder body away from the back plate (on one side) causing the cylinder to become out of line. This eventually moved enough to 'miss' the edge of contact edge of the shoe. It just so happen to 'miss' the edge of the shoe when the MOT tester applied the brakes!!

Strange to believe but true!!!

I know I lost a substantial amount of fluid. The inside of the wheel was lathered, as was the drum and complete brake assembly. When it stood on my drive awaiting my inspection, a considerable pool had formed and fluid was still dripping from the back plate. The reservoir had pretty much emptied.

Dan

:)I think fordfan has the right idea, especially as it had virtually emptied the reservoir. Bleed the brakes at the master cylinder first, followed by bleeding at the wheels.

:)I think fordfan has the right idea, especially as it had virtually emptied the reservoir. Bleed the brakes at the master cylinder first, followed by bleeding at the wheels.

Thanks for this. Would I be able to bleed the master cylinder using the Eezibleed or conventional method? It is a bit tight around the master cylinder/servo area is there any hints/tips to make this a bit easier to access??

After bleeding the master cylinder, do I then just bleed the rest of the system as normal, as Haynes manual suggests bleeding both front then both rear simutaneously and THEN bleeding each line again as normal?

Thanks

Dan