Spongy Breaks

[lozo87]

Hi, Posting here as Im not having much luck in the other forum...

Ive recently changed the rear calipers on my Audi A3 2ltr TDI. Changing them wasnt an issue and they were relatively simple to do. I've checked the Haynes manual and it said if the front section hasnt been disconnected then you shouldnt need to bleed this part of the system so it then states bleed rear right first followed by the rear left. So I followed the manual to the work compressing the break to build pressure and then pushing it to the ground while a friend turns the nipple by half a turn to allow the air and fluid to travel out. Felt fine when we were doing it felt like there was good pressure until I start the car up....

The lever is spongy and travels at least half way down before you attempts to break... Fine if you suddenly hit the breaks but if you coming to a gradual stop there spongy and it just doesnt feel right....

Im not sure what Im doing wrong... Should all four calipers be bled? Ive checked the reservoir while bleeding it and its had plenty of fluid in it.... Utter nightmare Ive bled breaks before hundreds of times and never had this issue......

Any advice would be appreciated !

 

[desertstorm]

Hello I have had an issue before like this with and found it was to do with the ABS system. Drive the car at 20 mph and brake hard to get the ABS system to cut in, it only needs to be for a second or so. See if that helps.
If that doesn't make any difference then it sounds like air in the system. If it's a 2007 car when was the last time the brake fluid was changed ?
It's not a bad thing to bleed the whole system.

Karl.

 

[lozo87]

Hi Karl,
Ive tried that and it stops straight away... I've never changed the brake fluid, Ive been told I need to pull alot of fluid through the nipple but how much is alot ?? Il try doing the whole system I think and jack him as high as I can get it to get the air out.

 

[desertstorm]

It shouldn't make any difference how high you jack the car. I use one of the Gunsons brake bleed kits, they are much easier and quicker to do the job and you can do it on your own. The flow is continuous rather than the pedal up / down process which does work but isn't as effective or quick.
I only use these with about 25 PSI in the tyre though as thats plenty of pressure.
Did you clamp the flexi to stop fluid loss / air getting into the system when you took the caliper off ?.
http://www.ebay.co.uk/itm/GUNSON-G4...t=UK_Hand_Tools_Equipment&hash=item2c68763fd2

 

[A3_130]

Sounds like there's definitely still some air in the system. You'll need to bleed all calipers in the order that the Haynes manual specifies and don't forget any bleed nipples on the master cylinder. I tried the manual method (the missus does the brake while i bleed each caliper) and I couldn't get all the air out so in the end I went for one of those Gunsons Eezibleed kits that Karl mentions and that was much better.