Grifter
Well-Known LVC Member
trying to track down the issue with my brakes.. what symptoms does a bad brake booster have?
what are the symptoms of a bad brake booster?
- Thread starter Grifter
- Start date
Dominus
Dedicated LVC Member
Hissing noise, stiff brake pedal, slow response.
lincolnboy
Dedicated LVC Member
Dominus said:
once the brake pedal is to hard to even press down an inch its bad. ..its an easy job. bout three or so bolts from the brake pedal and the rest from the brake booster and reninstall and bleed brake line
Grifter
Well-Known LVC Member
ok, then its definitely NOT a bad brake booster..
i can bleed the brakes, get a firm pedal, turn on the car, step on the brake and its gone. Soft, nothing there, barely holds the car in gear.. i am thinking i have a bunch of air in the ABS pump.. (yes i know how it gets there, and how it got there)
I replaced and bench bled a new master cylinder, nothing changed..
the ABS might just be on its way out the door in favor of real brakes.. good way to get rid of the traction control too..
i can bleed the brakes, get a firm pedal, turn on the car, step on the brake and its gone. Soft, nothing there, barely holds the car in gear.. i am thinking i have a bunch of air in the ABS pump.. (yes i know how it gets there, and how it got there)
I replaced and bench bled a new master cylinder, nothing changed..
the ABS might just be on its way out the door in favor of real brakes.. good way to get rid of the traction control too..
Dominus
Dedicated LVC Member
Real brakes? If ABS is not real brakes, what is?
Dern Humpus
Dedicated LVC Member
I would have guess master cylinder, but since you replaced it I am of no help.
Grifter
Well-Known LVC Member
real brakes are non abs..
standard vacuum assisted non abs brakes.. (i dont like abs)
standard vacuum assisted non abs brakes.. (i dont like abs)
lincolnboy
Dedicated LVC Member
first off what is it doing....
Grifter
Well-Known LVC Member
ok, heres the long story..
first off, it started because i replaced the engine.
while pulling the old motor and putting the new motor in, the frontmost brakeline off the master cylinder got hit a few to many times. it developed a crack, and i didnt know it. in the same process of the car rebuild, i swapped in PBR calipers and did the hubswap. so i had to bleed the brakes. so that crack in the line forced air into the ABS pump. once i found the cracked line, i replaced it. bled the new master cylinder, and bled the enitre system correctly several times. while i bled the system, the brake pedal feels ok. good resistance, no fading. Then i fire up the car, and step on the brake, and i have a bit of brake for about a second, then it fades to the floor. wheni let off, it comes back up like it should, but step on it and its fading to the floor again.
The entire fluid system has fresh synthetic brake fluid in it. It has been bled so many times that the whole system is new fluid. its all clear and good. All 4 rotors are new, and so are all of the pads.
Now, on a 1997 Mark, i have the Teves Mark 20 ABS system. with the 1993-96 Marks, its a Teves Mark IV. The Teves IV system can be bled with a $49 tool. The Teves 20 system requires a scan tool. I bought a Snap-On MT2500 Scan tool with the 1998 ABS cartridge. There isnt any support for the Teves 20 system on Fords with that cartridge.. So i cant bleed it with that..
so that led me to think about what it could be if it wasnt the ABS pump, hence my question about the brake booster..
first off, it started because i replaced the engine.
while pulling the old motor and putting the new motor in, the frontmost brakeline off the master cylinder got hit a few to many times. it developed a crack, and i didnt know it. in the same process of the car rebuild, i swapped in PBR calipers and did the hubswap. so i had to bleed the brakes. so that crack in the line forced air into the ABS pump. once i found the cracked line, i replaced it. bled the new master cylinder, and bled the enitre system correctly several times. while i bled the system, the brake pedal feels ok. good resistance, no fading. Then i fire up the car, and step on the brake, and i have a bit of brake for about a second, then it fades to the floor. wheni let off, it comes back up like it should, but step on it and its fading to the floor again.
The entire fluid system has fresh synthetic brake fluid in it. It has been bled so many times that the whole system is new fluid. its all clear and good. All 4 rotors are new, and so are all of the pads.
Now, on a 1997 Mark, i have the Teves Mark 20 ABS system. with the 1993-96 Marks, its a Teves Mark IV. The Teves IV system can be bled with a $49 tool. The Teves 20 system requires a scan tool. I bought a Snap-On MT2500 Scan tool with the 1998 ABS cartridge. There isnt any support for the Teves 20 system on Fords with that cartridge.. So i cant bleed it with that..
so that led me to think about what it could be if it wasnt the ABS pump, hence my question about the brake booster..
djKale
Dearly Departed Friend
IIRC, you are describing exactly what happened when my brake booster failed. I would have brakes for a period of time, then the pedal would slowly go to the floor, eventually requiring maximum pedal effort to stop. I replaced the booster with one off a TBird and my problems went away. It was NOT an easy job. In fact it was a pain in the ass! It's one of those jobs that will be a lot easier the next time you have to do it, but you gotta get that first round under your belt.
Kale
Kale