delly

well made the mistake of not driving my 200q for 3 months.

I had a siezed rear caliper so i replaced it and bled the brakes today. took it for a drive today and seems like a bad master cylinder. pedal mushy and weak brake power. no fluid leaks and bomb is working fine.

anyone know a good source for an MC? anyone got a btdt for changing out. they must be fairly robust as a search of the archives doesn't bring up much.

any help apprec.

Kneale Brownson

Did you use a pressure bleeder like Audi recommends? Did you follow the recommended procedure of RR, LR, RF, LF, clutch slave?

Did you just bleed a little or did you flush?

delly

i used a pressure bleeder and i only did the RR the caliper i changed. fluid is quite clean as i did a flush last fall. perhaps i should have bled all lines? normally i would but i had such a time loosening some of the bleeder screws last fall and figured i got all the air out.

your thoughts?

Kneale Brownson

When you took the caliper off, I'd guess you allowed some air pockets to form elsewhere. I'd bleed 'em all.

Even though you had trouble opening bleeders last fall, they should open easier this summer. I use a 6-point socket to loosen bleeders rather than a box end wrench. Seems to grip better without rounding over the corners.

paulfern2000

this does not mean it is the same...but worth a try...for me the fix cost 4 bucks!!

My car had stood still for about 1 year. while I restored some of the car.

The problem was actually the rubber grommets on the master cylinder (where the reservoir bootel sits on the cylinder) They went soft or porus somehow...worst is they seemed to have enlarged with the sitting around time..not sure how that works out. Anyway I changed then and probelm is fixed.

delly

Paul how does the reservoir detach from the master cylinder?

Kneale Brownson

Pry upward carefully. It's old plastic and you don't want to break off the nipples. The grommets serve to both seal the interface with the master cylinder and keep the tank in place, so they have quite a grip.

<img src="http://www.vagcat.com/p/B088/053000.png">

paulfern2000

exactly thanks Kneale.

as he mentions basically.. however if you notice that pulling the reservoir is very easy...this is a sign the grommets are bad or have gone bad.

On mine I had to use little force to pull it.

Just a trick however to help pull the hard ones..spray some WD40 in the area of the grommets...if possible down where it is mates to the cylinder.

S4for73

They don't have to be that tight. And I would put a little grease on the threads. When the factory installs them they just grab a handfull out or a barrel and do not lube them.

delly

update... LF bleeder frozen. others all able to loosen. used PB blaster and a 6 point and a little hammer action. nothing yet... but i am trying to b patient. in meantime i read some more on the master cylinder problems and convinced mine gone bad... so have ordered new one.

Kneale don't see anything in the bentley about bleeding clutch master as part of brake bleeding. is it difficult to do?