VONBOTTLE

so on my '08 S6 my brake pedal the last few weeks had gotten soft off and on and now is soft all the time having to push the pedal almost to the floor to stop - i would assume my master cylinder is bad? i looked under the cowl and could see the existing cylinder is TRW which is what ECS carries as well as VW brand for almost twice the cost - i don't see any point in using the VW considering the labor to install and bleed the brakes would equal the difference in cost, but would you advise against going with any of the mfr. that rockauto carries for like $100 (Centric,AD delco, Raybestos)? i'm somewhat wary of them, and also why is the supposedly same TRW part $80 cheaper from Autohauz? (i've never really dealt with them so i'm more trusting of ECS).

also, i need to replace both front axles, do you see any labor savings by doing the master cylinder and the axles at the same time or is there really no repetetive labor?
i'm sensing a big tax bill coming up and figuring out how to budget for these repairs......i'm unloading my '00 A6 2.7T if anyone is interested!

occhis

Not sure why you would assume the MC is bad just because you have a soft pedal. Why don't you check for leaks and if none, bleed the system. You may put a new MC on and still have the same problem if a leak or air in the system is the cause.

VONBOTTLE

I forgot to mention my mechanic said the cylinder had a sticky float last time it was in for service, also the brake light on the dash has been flashing the last few weeks, I haven't noticed any fluid leaks

royclark

Have you checked that your fluid level is OK ?
When was the last time that the brake fluid was changed ?

VONBOTTLE

I just assumed my mechanic checked it, but when you assume......i know.....bought the car last year with no service records so was going to change fluid regardless. I'll check now, of course car is dead now, hopefully it's just the battery after last nights -12 temps

VONBOTTLE

Well thankfully it was just the battery, took forever to jump, but finally turned over....only a year old battery too. Of course the 12 year old battety in my wife's volvo cranks just fine.....and the brake fluid level was fine. Given the soft brake pedal was off and on for a few weeks prior to the constant soft pedal now, i'd imagine it was not a fluid issue

Abcaudi

My master cylinder has been empty after my rear caliper failed. So the system has been dry for i while now.

I wonder if there are any tips on how to get the brake system full with fluid again.

I have read about some methods

- Bench bleed - but i havent been able to take out the MC because of the long screw.
- Bench bleed in car - Not so much info about that
- Pressure bleed - Will this work for a dry MC?
- Gravity bleed - This method seems to be the easiest. But how long? Will it really work?

I guide on ABS bleed with VCDS step by step

Please some guide on any will be thankful.

And i have also read about clutch? My car is Allroad 2002 automatic 2.7.