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Topic: Pedal goes to the floor, hissing sound (Read 9571 times) previous topic - next topic

Pedal goes to the floor, hissing sound

Reply #15
I logged on this morning with the same problem.

I also get the hissing sound, the pedle goes straight to the floor, and no brakes.  The m/c fliud level is fine.  I didnt see any fliud on the ground, but I didnt check the inner tires or pull a wheel.

Seems like I should still have front brakes if the rears are bad.

Pedal goes to the floor, hissing sound

Reply #16
K, first things to check when you get a hissing:

- Make sure the brake booster check valve (where the large vacuum line from the manifold attaches to the booster) is properly seated. It is designed so that you can have a slight attachment angle and still not leak...but double check it anyway. Might need pushed in, or replaced (it's a $5 HELP! part). Also, inspect the vacuum line for cracks.

- If your car was originally equipped with the automatic parking brake release option, you'll have a thin white vacuum line going from the B/R port on the vacuum tee under the hood, through a hole in the center of the firewall, and down to a white collar at the base of the steering column, near the brake pedal. Make sure that line is attached (or capped off), or that the line didn't break.

Otherwise you're more than likely looking at a new booster.

Pedal goes to the floor, hissing sound

Reply #17
Quote from: EricCoolCats;153409
K, first things to check when you get a hissing:

- Make sure the brake booster check valve (where the large vacuum line from the manifold attaches to the booster) is properly seated. It is designed so that you can have a slight attachment angle and still not leak...but double check it anyway. Might need pushed in, or replaced (it's a $5 HELP! part). Also, inspect the vacuum line for cracks.



In the winter time, the check valve in my t-bird would freeze...after letting it idle for 10 minutes, I had power brakes again.
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

Pedal goes to the floor, hissing sound

Reply #18
i have the same problem to but i figured that out where the hissing/ bubbling sound is coming from and its coming from the brake booster. so is it better to replace the master cylinder to at the same time or just replace the brake booster?
84 el camino ss-daily driver(efi mild sbc,2004r, posi 3:42 rear.)
84 mercury cougar v6- was a v6/ nitrous drag car, going back to mostly stock
81 chevy malibu-protouring/  drag car.( efi sbc supercharged 283 that will rev to the moon, 2004r, 4:11 posi rear)