Excessive Brake Pedal Travel

[jaym15try]

After some advice. Did the brakes on my 2000 A3 1.8T about a couple of years ago, all that went well until I started to bleed the brakes. Halfway through bleeding them (Manual 2 man method) the pedal suddenly sank to the floor. With the car switched off the pedal would feel fine, but when the car was on, the pedal would soften up. Managed to get them so there was some braking albeit near to the floor.
Anyway had the car to a (general) garage, they bled them and even though better than my attempt, it was still not right with braking very low down.
Lastly had the car to an Audi specialist who did the same and had the same results as the previous garage. So even the brakes are adequate (passed through 2 MOT’s ok) its still not right :confused:

Fast forward 2 years and I’m determined to get it sorted. Having searched the net on this topic for Audi A3/VW Golf MK IV’s it seems like the master cylinder seals could have been damaged, so I’m looking to get that done.
Any idea’s on how much this would cost (I’m in the UK) and the best tried and tested procedure on carrying this out. I’ve read that the ABS unit would need to be bled using VAG.com.
Thanks in advance :1zhelp:

[NickPicks]

Use a pressure bleeder. The gunsons eezibleed which runs off the spare tyre pressure is fine, although I did need to fill it up 4 times whilst bleeding. It is very important to reduce the pressure in the tyre to 1 bar. You also need to bleed the brakes in order, which I can't remember off the top of my head (I think that's only to minimise the fluid bled).

Unless you've run the fluid reservoir dry, you shouldn't need to bleed the abs unit. I think you might be right about setting it into basic mode with vag com, but I'm not sure how to do this.

An Audi dealer just quoted me £49 to renew the brake fluid, which is basically the same procedure as bleeding. It might cost a bit more if you have got air in the abs pump, but I wouldn't have thought it would be much more.

[NickPicks]

Here's a link to a thread about a mk4 Golf, which I think will be is pretty much the same as the A3 procedure.

Link here (http://www.vwaudiforum.co.uk/forum/showthread.php?t=79327)

In it, Crasher explains how to do a basic settings bleed with the abs pump. It looks complicated, and you'll need a laptop with a registered version of vag-com. Since it'll cost you at least £15 for a lead, and $99 to register it, and it looks complicated, I think I'd take it to someone else to do. Crasher says it should take a competent independant about an hour to do.

There's a dealers, independants and breakers (http://www.vwaudiforum.co.uk/forum/forumdisplay.php?f=43) section to find your nearest recommended specialist. If you're near Nottingham, I'd recommend C&R Enterprises (http://www.vwaudiforum.co.uk/forum/forumdisplay.php?f=204) who are a forum sponsor. Crasher seems to know what he's talking about.

[Crasher]

Yes, you need to do a basic settings bleed and even that can fail to improve things, they can be extremely difficult to get back to a good pedal, I have often had to go through the procedure three times.

[jaym15try]

Thanks guys
I think it may be just air in the master cylinder, so I've got a Gunsons on order

20 PSI, a good seal on the MC reservoir and logs of rags around the master cylinder seems to be the general consensus

Read on one of the posts that the lower nipple (nearest to bulkhead) is bled first then the higher one last.

The system hasn't been run dry so there shouldn't be air in the ABS pump

If doesn't sort it then I'll do the brakes again RL/RR/LF/RF, Clutch then Master Cylinder.

I'll post back with my results