pump brakes and get a hard pedal but as soon as you release the pedal, the pedal goes to the floor

Asked by May 10, 2014 at 08:39 PM about the 1968 Mercury Cougar

Question type: Maintenance & Repair

Had a leaky proportioning valve. Replaced it, distribution block, master cylinder and all
front lines. Pre-bled the master cylinder and Bled brakes several but as soon as you
release the pedal, the pedal goes to the floor. All this done with the engine not running.
Does anyone have a suggestion on what is wrong?

5 Answers

135

Does it do it with the engine running? If not, you could have a vacuum leak maybe in the brake booster.

7,155

That valve should have a reset button on it at the top so try resetting it. Alos, open up the front brake bleeders and let them run for a few minutes keeping the master cylinder reservoir full while doing it. Good Luck, Kenny/MrBlueOval

7,155

I can't type today, LOL !!! The above should read "Also" not Alos.

115

sounds like you got a bad master cylinder, don't buy a rebuilt master cylinder, buy a brand new one, better be safe then sorry, and if their is a leak in the booster you will here the air escaping and the car will tremor when you push on the brake, My proportioning valve has been rebuilt and is original but I don't have a reset button on the valve.

1 of 1 people found this helpful.
115

did you bleed all 4 wheels,start from the back passenger side bleed it 3 times, then the back passenger driver side bleed it 3 times, next is the front start at the passenger side bleed it 3 times then go to the front driver side bleed it 3 times,

Your Answer

Cougar

Looking for a Used Cougar in your area?

CarGurus has 159 nationwide Cougar listings and the tools to find you a great deal.

ZIP:

Mercury Cougar Experts

  • #1
    lisagayle
    Reputation
    2,210
  • #2
    Tom Demyan
    Reputation
    820
  • #3
    Jessica Cornelison
    Reputation
    610
View All

Related Models For Sale

Used Ford Mustang
343 Great Deals out of 41,955 listings starting at $1,488
Used Ford Thunderbird
15 Great Deals out of 1,007 listings starting at $6,490
Used Chevrolet Camaro
373 Great Deals out of 31,430 listings starting at $3,495
Used Dodge Charger
325 Great Deals out of 36,246 listings starting at $1,999
Used Pontiac Firebird
6 Great Deals out of 692 listings starting at $3,911
Used Pontiac GTO
3 Great Deals out of 391 listings starting at $3,950
Used Pontiac Grand Prix
9 Great Deals out of 2,438 listings starting at $2,200
Used Mercury Comet
24 listings
Used Chevrolet Impala
507 Great Deals out of 32,198 listings starting at $1,000
Used Chevrolet Corvette
115 Great Deals out of 16,222 listings starting at $3,995
Used Mercury Marauder
27 listings

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.