Brake problem

[Ericutlass]

Hi all,

I have a pb with my brakes, brake fluid seems to go from the rear reservoir of the master cylinder to the front one and when the level is low in the rear reservoir my brake light on the dash switch on and the pedal goes to the floor so it becomes difficult to stop the car.
No leaks detected at the wheels or anywhere, any ideas ? master cylinder, proportioning valve ?

Thanks
Eric

[Firethorne77]

Eric-
Get someone to help you bleed out the whole system first.
If that doesnt cure the problem, pull the master cylinder and bench bleed it if possible.
Sometimes you can get air trapped in the system between the booster and the master cyl.
If bleeding it out doesnt work, replace the master cyl, its a cheap enough fix. Especially since you have no other leaks showing on the lines out to each wheel.

[73CS]

Hi Eric, I know they probably are hard to find in France, but I would replace the Master Cylinder.

Blane

[Ericutlass]

Firethorne77

I've bled out the brake system a couple of time with my son and it went not better.
I'm gonna bench bleed the master cylinder as you said and bleed out again at the four wheels.

73CS

If it don't come better i will replace the master cylinder as you said, they are not specially difficult to find in France but they are very very expensive.
I have a friend in Cleveland OH and i asked him a couple of months ago to buy and send a new one to me, it sit in my garage so if i need a to replace it i will not loose time.

Thanks a lot to you guys,

Eric

[Ericutlass]

Bench bled the master cylinder yesterday, small bubbles of air went out in the rear container of the master cylinder and i noticed that when i released the piston of the master cylinder the brake fluid didn't come back every time in the rear container ( about 1 time for 4 pressure/release motions ) but The brake fluid comes back every time in the front container after releasing the piston.
I noticed too that the piston was very hard to push, i tried to push the piston on the new master cylinder and made it go about 1 inch without problems, on the master cylinder on the car it's difficult to push more than 1/2 inch.
With my son we bled out at the four wheels and made a short road test (2 or 3 miles), all is ok.
Will drive the car longer this week end and if the problem happens again i will change the master cylinder.

Eric