Hi all,
I did a search and came up with nothing for some reason. I would have thought this had been talked about. Anyway, I refreshed the brake and suspension system on an 01 this past weekend, not mine. I used blue racing brake fluid instead of regular fluid. The car got new rotors, painted calipers and braided lines. The car has 105K on it.
Now, I bleed the system well, yet have no peddle pressure at all. You can pump it rapidly and get a little peddle, but stop and the peddle goes to the floor. My question is, could the fluid be the cause or is the master cylinder gone? I have even taken the master cylinder out and bench bleed it and then re-bleed the entire system and still no peddle. While bench bleeding, and while in the car the fluid flowed well and appeared to have no problems.
What do you think? Could really use some advice. This is my first time using the blue brake fluid and I'd just like to make sure before buying a new master for this thing. Or, is something else wrong that I am just not thinking of?
TIA,
Will

 

It's not the fluid. I've used ATE Super Blue brake fluid for years on my bikes and cars/pick-ups. I alternate it at changes with a clear fluid so it's easier to see when the old fluid is fully purged. Never a fluid problem.

 

There may be air in your brake lines. Need to bleed some more.

Use a motive power bleeder or a kid to pump your brake peddle 2 or 4 times, and hold the peddle in while open the bleed screw bleed each caliper.

 

I'm using the Super Blue stuff on my car for almost 3 years now with no problems, so I don't think it's the fluid at all.

I hope you get the problem solved.

 

Thanks for all the help, kinda figured it wasn't the fluid. I've bled and bled and bled the lines. I even took the master out and bench bled it, then did the entire system over again taking the fluid down to half four times. And nothing different. The only thing I can think is that it's the master. Since I never used the fluid before, I figured it couldn't hurt to ask since that was the only thing I changed that far up in the brake system.
Thanks again, and if anyone else has a suggestion please feel free.

 

How did you bleed it? Pumping the pedal? And how old was the fluid? (i.e., has the system been regularly maintained with fluid changes?)

If you used the full stroke of the pedal and the fluid was old, I'd betcha that the master cylinder seals were shreaded by corroded walls of the master cylinder.

In the normal range of brake motion, the cylinder walls usually remain smooth and clean because they are constantly being wiped by the piston seals. The parts of the cylinder which don't normally see a seal go by often corrode from the water in old brake fluid. Then, first time the pedal is stroked fully during a brake bleeding exercise, the seals are raked through a bed of sharp edges. Sometimes the cylinder can be saved by light honing and a rebuild kit, but more often than not it makes more sense to just replace it.

The fact that you say that you can at least get a little pressure, but it immediately bleeds away, suggests the issue isn't air (the pedal would be soft, but it wouldn't bleed off much, if at all). Sounds like the mc to me.

HTH,
Mark

 

Mark, thanks much for responding. When bleeding the lines I did use the, pumping the peddle method. Since all I changed down low were the lines I went with doing that. At first like always the peddle did move outside it's norm due to the bleeding.
This is the second time I have worked on the car for the guy. First time on the brakes. To my knowledge and after looking at the nasty fluid that came out, it's the first time the fluid's been changed. , yeah I know. He just drives it, you know what I mean.
I did order a new master cylinder today, will be in tomorrow morning, so hopefully. Thank you again, and your response was most helpful.