still have brake problems
Thread Starter
Cruising
Joined: Sep 2003
Posts: 13
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From: Clyo GA
still have brake problems
I bleed the master cylinder then gravity bleed the brakes. I manually bleed the brakes as recommened . I have a real good pedal,but when i start the car the pedal goes to the floor.could the booster be the culprit.
:banghead:
I have replaced the master cylinder and all four calipers .
:mad
[Modified by REC3, 3:18 AM 10/26/2003]
:banghead:
I have replaced the master cylinder and all four calipers .
:mad
[Modified by REC3, 3:18 AM 10/26/2003]
Safety Car
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From: St. Charles IL
Cruise-In 5-6-7-8-9-11-12 Veteran
A CI-6 Car Show Winner
Re: still have brake problems (REC3)
More likely it's the master cylinder, if youare not losing fluid anywhere. Welcome to the forum! :cheers:
Le Mans Master
Joined: Jul 2000
Posts: 6,664
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From: columbia city in
Re: still have brake problems (REC3)
did you bleed the brakes in the proper order ?i think it is rr. lr.rf.lf.also check vac line to the brake booster if that is alright ,afterruning motor for a minute or two ,where the hose goes into the booster try pulling it out alittle bit to see if you have vacuume in the booster .when i changed my rear calibers it did take awhile to get all the air out .
Safety Car
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From: St. Charles IL
Cruise-In 5-6-7-8-9-11-12 Veteran
A CI-6 Car Show Winner
Re: still have brake problems (REC3)
Yes, I would still be favoring the master cylinder. The pedal linkage is basically a direct connection to the piston of the master cylinder, only assisted by the booster diaphragm. Was your master cylinder new or rebuilt? I've had considerable problems with rebuilt components, but I suppose even a new one can be defective. You mentioned the master was bled, by bench method? Could still have some air, but seems odd you would get a good pedal height then it goes away once started. Could try bench bleeding the master cylinder again.
Thread Starter
Cruising
Joined: Sep 2003
Posts: 13
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From: Clyo GA
Re: still have brake problems (Big Fish)
Thanks Big Fish !!
The master cylinder is rebuilt . I bench bleed it , blew out the lines and started fresh . First I bleed the brakes to distribute the fluid , then gravity bleed . I bleed the master cylinder agian , then bleed the brakes . Good pedal . After starting the car , no pedal . I removed the vacume line from the booster . got a good pedal . When I replaced the vacume line I got no pedal agian . I guess I will try starting over , if that doesn't work I can repalce the master cylinder agian .
The master cylinder is rebuilt . I bench bleed it , blew out the lines and started fresh . First I bleed the brakes to distribute the fluid , then gravity bleed . I bleed the master cylinder agian , then bleed the brakes . Good pedal . After starting the car , no pedal . I removed the vacume line from the booster . got a good pedal . When I replaced the vacume line I got no pedal agian . I guess I will try starting over , if that doesn't work I can repalce the master cylinder agian .
Safety Car
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From: St. Charles IL
Cruise-In 5-6-7-8-9-11-12 Veteran
A CI-6 Car Show Winner
Re: still have brake problems (REC3)
I am second guessing myself now, this is a strange problem. Do you get the brake warning light when the pedal goes to the floor? if so, could be the master cylinder is OK, but there is still air in the lines and/or calipers. No light? I would still favor the master cylinder. These systems are not easy to bleed. Logic would say bleed RR inner, then outer first, then LR, RF, LF. Sometimes you can get better results bleeding LR first. This is a 2 person job, one in the car depressing the pedal, another closing the bleeder at the bottom of the pedal stroke, then repeat until all air purged from each bleeder. It helps to have a hose from each bleeder held below the fluid level in your bleeder jar to observe any air bubbles with each pedal stroke.
Thread Starter
Cruising
Joined: Sep 2003
Posts: 13
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From: Clyo GA
Re: still have brake problems (Big Fish)
Hi BIG FISH.
I DO GET THE BRAKE LIGHT WHEN THE THE PEDAL GOES TO THE FLOOR.
I'AM GOING TO TRY AND BLEED THEM AGAIN THIS WEEKEND,I'LL LET YOU
KNOW WHAT HAPPEN'S THANKS FOR YOUR HELP.
GREAT LOOKING CAR YOU HAVE THERE,HOPE MINE WILL LOOK AS GOOD
SOME DAY.
REC3
I DO GET THE BRAKE LIGHT WHEN THE THE PEDAL GOES TO THE FLOOR.
I'AM GOING TO TRY AND BLEED THEM AGAIN THIS WEEKEND,I'LL LET YOU
KNOW WHAT HAPPEN'S THANKS FOR YOUR HELP.
GREAT LOOKING CAR YOU HAVE THERE,HOPE MINE WILL LOOK AS GOOD
SOME DAY.
REC3
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Safety Car
Joined: Aug 2001
Posts: 3,683
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From: Waterford Mi
Re: still have brake problems (REC3)
How are you bleeing them. Foot pedal, vacuum, or pressure bleeder? I have done them all three ways and not had any problems. If you are using the gravity method then I suggest you try to pressure bleed them. I have had the valve shift and not let enough flow to the rears to get all the air out.
Good luck
Good luck
Le Mans Master
Joined: Apr 2000
Posts: 7,562
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From: B'Ville NY
Cruise-In III Veteran
St. Jude Donor '05
Re: still have brake problems (REC3)
I'm currently see similar results with my own car, but have manual brakes :crazy: . I will be looking to replace the MC while I have the car apart over winter ;) . I'm interested to see what you find :cheers:
Thread Starter
Cruising
Joined: Sep 2003
Posts: 13
Likes: 0
From: Clyo GA
Re: still have brake problems (REC3)
I TRIED BLEEDING THE BRAKES AGAIN THIS WEEKEND WITH A VACUME
PUMP NO LUCK. SO I TRIED THE GRAVITY SYSTEM AGAIN FOR TWO HOURS
ON THE REAR WHEEL AND ALL GET IS AIR BUBBLES. I DON'T SEE ANY LEAKS
SO WHERE IS THE ---- AIR COMING FROM.
NEED HELP BAD.
THANKS REC3 :mad
PUMP NO LUCK. SO I TRIED THE GRAVITY SYSTEM AGAIN FOR TWO HOURS
ON THE REAR WHEEL AND ALL GET IS AIR BUBBLES. I DON'T SEE ANY LEAKS
SO WHERE IS THE ---- AIR COMING FROM.
NEED HELP BAD.
THANKS REC3 :mad
Thread Starter
Cruising
Joined: Sep 2003
Posts: 13
Likes: 0
From: Clyo GA
Re: still have brake problems (REC3)
does anyone know what my problem is . i tried the gravity bleeding again
all i get is air bubbles. :confused:
REC3.
[Modified by REC3, 11:42 PM 11/9/2003]
all i get is air bubbles. :confused:
REC3.
[Modified by REC3, 11:42 PM 11/9/2003]
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: still have brake problems (REC3)
If you have a rebuilt master cylinder, that is most likely the problem .. Rebuilt parts (even brake cylinders) are know for being very poor quality. Usually the box is worth more than the part. Junk!
Safety Car
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From: St. Charles IL
Cruise-In 5-6-7-8-9-11-12 Veteran
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Re: still have brake problems (REC3)
[QUOTE]does anyone know what my problem is . i tried the gravity bleeding again
all i get is air bubbles.
If all you get is air bubbles, the problem is simple: there is still air in the system, providing you have been keeping the master cylinder full throughout the bleeding process.
all i get is air bubbles.
If all you get is air bubbles, the problem is simple: there is still air in the system, providing you have been keeping the master cylinder full throughout the bleeding process.
Safety Car
Joined: Jul 2002
Posts: 4,269
Likes: 3
From: St. Charles IL
Cruise-In 5-6-7-8-9-11-12 Veteran
A CI-6 Car Show Winner
Re: still have brake problems (REC3)
I would try the 2 person bleeding again. Start with left front, then right front, then left rear inner,then outer, then right rear inner, then outer. You are bsically working from shortest line to longest line. Be sure to open the bleeder and fully depress the brake pedal each time, hold to the floor, then close the bleeder valve, then release the pedal and repeat until all air is purged from each location. The idea here is to prevent air entering the system from a shorter line that is still holding air. If that won't do it have the brakes power bled by a service shop that has the equipment. These systems are not easy to get the air out of, I wound up having mine power bled as well, and have had no problems.
Pro
Joined: Feb 2003
Posts: 508
Likes: 1
From: Maplewood NJ
Re: still have brake problems (REC3)
I had some problems getting all the air out of my system too when I replace the calipers and the MC. I ended up bleeding the air out of the MC on the car then gravity bleeding the calipers for about two weeks :lol: . . . that wasn't quite intentional, but it worked out well :D . My pedal seems to be firm when the car is off, and when I start the car, it goes down quite a bit, but not to the floor. However, it doesn't take that much pressure for the brakes to start slowing the car down. I haven't tried locking the wheels, but the car passed the state inspection.
Matt
Matt
Racer
Joined: Mar 2003
Posts: 282
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From: London
Re: still have brake problems (REC3)
i TOTALLY sympathise! i had the same problem... starting the engine and suddenly my pedal was gone. Rebuilt my master cylinder (for the second time) but no luck.
My calipers weren't brand new though, and i found a bit of a leak in one of the front calipers... once i replaced the seal things got better.... though not great. Then i noticed that my (fairly old) brake pads were actually a bit warped (the metal plate bit).. therefore there was quite a bit of pedal travel before the entire brake pad was pressing properly against the disk (not a very clear technical description, sorry!)... anyway, changed my pads and it made quite a difference.
I presume you've got new pads anyway, but though i'd mention it!
good luck :smash:
My calipers weren't brand new though, and i found a bit of a leak in one of the front calipers... once i replaced the seal things got better.... though not great. Then i noticed that my (fairly old) brake pads were actually a bit warped (the metal plate bit).. therefore there was quite a bit of pedal travel before the entire brake pad was pressing properly against the disk (not a very clear technical description, sorry!)... anyway, changed my pads and it made quite a difference.
I presume you've got new pads anyway, but though i'd mention it!
good luck :smash: