bjones74

Have been having soft brake problems and now the brakes are all the way to the floor. I beleive the problem is the master cylinder. I have another one to put on and need some help with the process and want to make sure I have the bleeding process right. After swapping out the master cylinder do I just bleed by:
1) Pump brakes
2) Hold pedal down
3) Open bleeder screw
4) Allow fluid out
5) Close bleeder screw
6) Repeat until no more air leaves

any help would be greatly appreciated. I miss driving this car.

DMS-Audi Quattro

maybe just maybe its your brake booster because thats what converts the energy from your foot to the master cylinder then to brakes

i havent had the problem sorry

Evilclown

It's probably the master cylinder. A bad brake booster would make the pedal almost impossible to press. Are you sure it's not just that the brakes need to be bled?

MikTip

Make sure none of your calpiers are leaking fluid or the hoses and lines!

Bad assist unit will make the pedal very tough to push.

bjones74

Not for sure, but they are completely gone. Thats why I thought maybe the plunger in the master cylinder is bad. Does anyone know if there is anything tricky about replacing the master cyl and bleeding the brakes on this old model?

DMS-Audi Quattro

its not that hard. just start with the wheel furthest away from the master cyl.

jnormandeau(93100CSQuattro)

It's a tube with a oneway flow valve on the end.
Open the nipple 1/4 turn, put the tube on it and the other end in a jar and pump away. Air cannot leak back into the caliper because of the valve.
It allows you to do the job solo and fast!
I bought mine at NAPA ~$5.