Brake problem after trackday - boiled fluid ?

[Matt_D]

Hmm ok still have a slight problem

Just changed the brake fluid for the ATE blue stuff.
Used just under a litre to chnage it all, thats sound right ?

Done in order as Jamo said rear passenger then drivers, passenger front then drivers but still have no pressure and the light flashes up on the autocheck still.
Clutch feels light (might be as i'm not used to it been driving the Land Rover for 5 days now and thats heavy) might have a go bleeding the clutch slave cylinder.

Anybody know where it is ?

[AndyP]

It's on top of the bellhousing. You reach it by removing the front nearside wheel and reaching through the hole in the wheel arch that the track rod goes through. You have to do it blind though as once your arms in there you can't see anything!
It's fiddly but not impossible.

Good luck

[dan_b]

@Matt - I would have used 2litres to flush just to be totally sure - did you really pull through all the gack, bubbles and fizz with just 1 litre?

Did you do it with the Ezibleed? With that you have to be careful not to push air into the system which can happen if the fluid level runs low or the bottle isn't always kept above the height of the main reservoir.

Also, have you checked thoroughly for any leaks in your brake pipes? Check for signs of dampness around all the joints, and also from the master cylinder and main reservoir.

Does sound like you need to check the clutch.

[Matt_D]

Dan - i used a good old fashioned brake bleeder made by draper for that reason i don't like these pressurised systems as they can put air into your system.
I have used just over a litre now to bleed/flush it all including the clutch, the brake fluid was'nt gunky or black just a dark gold colour.

I have bled my clutch this morning and gone round and taken some more fluid out of every caliper.
It seems much better but i think still not 100%
The braking performance is all there but you can touch the floor with the brake pedal if you stamp on it hard enough where as before it did'nt.
The ABS cuts in ok it does'nt pull left or right so a caliper is'nt seized/seals damaged, what i might have done is damaged the seals in the master cylinder from where the brake fluid got so hot.

The trouble is the last time i drove the audi it had virtually no brakes and i've been driving my landy for a week so its hard to remember what the audi brakes were like

At least i can drive it now Just got to sort my boost leak now

[Fat Audi 80]

If its any help your pedal should be rock hard after an inch of travel or so. If it does not go rock hard there is air somewhere or you have seal problems with the master cylinder. (Assuming you defo have no leaks on any of the calipers as you state).

HTH

Good luck

Cheers,

Steve.

[nip]

sorry matt havnt been on for a bit, it was a silver m3 evo this 1 sorry about poor quality pic

[dan_b]

@Matt that still doesn't sound remotely right, reckon you've either still got air in there, or a leak.

[Matt_D]

No leaks anywhere, possibly have air in the system still as it has ABS it might need pressure bleeding

[dan_b]

That's why the Ezibleed is useful

[macspring]

One man bleeding is good

Nice to be able to give my small tuppence back to this forum, as it is a mine of info from individuals who are very unselfishly and repeatedly giving of their time, to post replies and also research links. It makes it much easier to own, maintain and enjoy these cars. I've found out loads and spend enjoyable endless hours carrying out "research".

Soft in the head bit now over, so here goes,

Since purchasing in 2003 a 1993 Audi Avant 2.0L 16v FWD, Engine Code - ACE the clutch always became jerky in slow moving traffic on a hot day. I aways thought the clutch was on its way out. However, we discovered when rebuiding my brother's identlcal example, that all mine needed to solve the hot weather/slow traffic jerky clutch problem was to bleed the line from the clutch fluid resovoir to clutch slave cylinder. Basically the fluid in this line was old and had absorbed sufficient water, as all brake fluid eventually does, and this water element of the fluid was boiling in the line in hot, slow moving traffic affecting the ability of the clutch slave cylinder to hold open the clutch.

So definitely bleed this particular line (last in sequence) when bleeding the brakes. If you're going to bleed the brakes go to www.sealytools.com and do a search for item no. "VS820". It is well worth the money and should get rid of any air still "hiding" in your brake lines. IMO it is better than the Eazibleed one that is "powererd" by the pressure in one's spare tyre.

I found the same problem with my S2 when I installed a new brake bomb and the pedal went much further down than before. Can't remember if I eventually cured it or it bedded in and the pedal firmed up, as the head gasket (thanks again to S2central.com for the diagnosis, in person) went and the car was "dropped over" to Corey for fixing and more.

Perhaps Corey would like to post a comment on the brake pedal going to the floor issue as described earlier in this thread?

Also, is there a rear brake compensator valve on an S2 similar to a Mk 1 Golf GTI, where it is impossible to bleed the brakes with the back axle hanging down in mid air? The car thinks it is braking extremely heavily and lets off the pressure to the back drums/calipers making it impossible to get a decent pedal, causing you to wonder if you could have damaged the seals on the master cylinder when pumping the pedal beyond it's normal length of travel to bleed the brakes. This may be another reason to bleed the brakes by a one man pressure method rather than by pumping the brake pedal with an assistant.

Not earth shattering stuff I know, but hopefully someone finds this post interesting/handy now or in the future.

Kind regards.

[Error404]

I niticed bleeding my rears that the pedal took quite a while to "recover", I.e. return to the top of the travel. I didn't have the engine running thought, so I might need to have another go at it... what would the slow reaction of the pedal indicate? Dodgy master cylinder / bomb?

[Matt_D]

Could still have air in the system, i to have got to do this again as its still not 100%