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Topic: Sloppy brake pedal. (Read 1236 times) previous topic - next topic

Sloppy brake pedal.

When I first apply the brakes, I have a nice stiff pedal. The front will lock, the back will not. After about 10 seconds, the pressure begins to bleed off until the pedal goes to the floor, and the car begins to roll. If I press the pedal again it is stiff and the pressure bleeds off again. I thought that it was the MC so I replaced it, and bled all the lines, but still have the problem. I don't see where any of the lines or anything else is leaking. I did the TC rear axle swap in '06, and haven't had a problem until now. I didn't use an adjustable prop valve, but I did gut the stock one and replaced the stock MC with one from a Crown Vic. as suggested. The car is unsafe to drive, and I am not sure where to go next. Any help is appreciated. The car is an '83 tbird with the 5.0.
 

Sloppy brake pedal.

Reply #1 –
If you're not losing fluid (doesn't need to be topped up), then there's an internal leak, and that spells master cylinder. Was the second MC new, used, or rebuilt?
Death awaits you all with nasty, big, pointy teeth.

1988 5.0 Bird, mostly stock, partly not, now gone to T-Bird heaven.
1990 Volvo 740GL. 114 tire-shredding horsies, baby!

Sloppy brake pedal.

Reply #3 –
was the mounting area of the booster wet?
is the inside of the booster vac line wet?
is there moisture inside the car up where the brake pedal parts enter the firewall?

do you hear hissing?

Sloppy brake pedal.

Reply #4 –
The booster/vac lines were not wet. There is no moisture on the firewall inside or outside of the car. I don't hear a hissing. I am starting to think I just got a bad MC out of the box. I am going to replace it again and see what happens.

Sloppy brake pedal.

Reply #5 –
your prob right on the MC , maybe worth buying it from the dealer instead.  We all know who's making all these aftermarket "NEW" parts anyway.