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Old 10-09-2007, 07:31 PM   #1
heliumbox
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Thumbs down Soft break pedal

Hello, I just bought a '95 Grand Am GT and it was cheap so it had a few problems. One of its problems was the breaks. My dad and his brothers decided to do the rear drum breaks themselves just for the sake of money. They have done many breaks in their time so they know what they are doing but for some reason the rear breaks do not seem to work. When we go try to aline the breaks by backing up and such and just testing them (after lots of bleeding) the rear breaks do not seem to get hot like the front. The "E" break works but not the normal breaks. Also they pedal is very soft and goes all the way to the floor whenever you turn the car on but when it is off it is a firm pedal like it should be. Sometimes the ABS light does come on but other times it does not. So that's my story and just wondering if anyone can help us out. Three days (20 hours or so ) working on them and we are all fed up and disappointed (especially my dad who thought he was doing the right thing buying me the car/first car) so any help would be greatly appreciated.
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Old 10-10-2007, 08:01 AM   #2
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Re: Soft break pedal

welcome to AF.

The adjusters(when backin up) need to be clean and turn freely to work properly. ANother thing could be the wheel cylinders/calipers are leaking or bad , loose or leaking brake lines.

With the pedal traveling to the floor you either have air still in the lines, a bad master cylinder , loose retaining bolts.
And could be the ABS modulator not working properly or air trapped in it....

I'd inspect for any leaks, bleed at the wheels untill the fluid runs clear and see if that improves pedal travel.

Make sure the master cylinderr doesnt go dry while bleeding the brakes !!

Also might not hurt to get the car scanned with an ABS capable scan tool.
This could give you some answers to whats malfunctioning.

good luck
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Old 10-10-2007, 03:25 PM   #3
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Re: Soft break pedal

Thank you and yes, we tried changing one of the wheel cycilders but .... they suck to get out and back in so we did not do the second. We have been told to bleed and bleed and bleed and we have probably flushed the entire system with new fluid. We were also told that the master cycilder could be bad so we were going to bring it to the shop on friday. We changed one break line because it was breaking, the other was fairly new. The other stuff is the first time I have heard of trying it so we'll give it a try, got to be worth a shot. Anyways thank you for the advice.
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Old 10-11-2007, 08:09 PM   #4
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Re: Soft break pedal

Hi again, Today we bought the master cylinder and we were just wondering if there are going to be any surprises or advice you could give us when instaling it. Thanks again.
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Old 10-11-2007, 10:29 PM   #5
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Re: Soft break pedal

Before thinking about the master, do this:

-Check to make sure whatever wheel cylinders and line you replaced are not leaking. Wash all brake fluid off components with brake cleaner and dry. Hold pressure down on the pedal while someone looks at the areas you just washed off to check for any leaks.
-Make sure master cylinder is full
-Make sure rear brakes are adjusted... The initial adjustment is made by tightening the adjuster until you get some drag on the drums.
-After you have verified all of the above, I would bleed all four wheels. This is the correct sequence: RR,LR,RF,LF... and make sure you are bleeding using the correct procedure... first make sure the engine is off, then pump the brake pedal a few time to deplete the vacuum reserve... then hold down the pedal, and tell the person to loosen the bleeder screw (MAKE SURE YOU ARE BLEEDING THROUGH THE BLEEDER AND NOT WHERE THE LINE SCREWS INTO THE CALIPER/CYLINDER)..as fluid shoots out, the helper should tighten the bleeder.. once tightened he should tell you to let up on the pedal. repeat again a few times, and then move to the next wheel.. KEEP MASTER CYLINDER ABOVE MIN LINE FOR ENTIRE PROCEDURE

See if any of this helps before replacing master
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Old 10-12-2007, 03:22 PM   #6
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Re: Soft break pedal

Alright thanks we will check for the leaks, we did bleed for a longggg time before looking at the cyilinder from the furthest point to closest but it didnt seem to help. The rear breaks just do not seem to get pressure, you can bleed them but they dont have enough pressure to close them. The initial adjusting was done before the drum was put on to the point where it just had a little drag. So we were basicly stumped.
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Old 10-12-2007, 05:24 PM   #7
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Re: Soft break pedal

If the rear brakes are getting no presure then its possibly the abs modulator(under the batetery) malfunctioning.

You'll need a Tech II scanner or other high end tool to check / purge,
but it can be bled.
Air can get trapped in this unit and its a real pita to get out with.

Hope that helps!
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Old 10-12-2007, 08:10 PM   #8
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Re: Soft break pedal

Awsome thanks for all the help guys, hope the ABS modulator isn't dead because I have a feeling that would be expencive. But yah we will try to bleed that again, who knows maybe there still is some air in the lines.
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Old 10-14-2007, 09:51 AM   #9
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Re: Soft break pedal

We changed the master cylinder, bleed all it before we put it in, bleed all 4 breaks and the ABS thing from furthest to closest and still can not get a pedal at all.... My dad thinks it may be the pistion thing that pushes the master cylinder pump but we do not know. We have tried everything we can think of, there are no leaks at all. So basicly all we are doing now is just a guessing game, we have no idea what else it could be. We doubt there is still air in the lines because we have flushed the entire thing like 5 times. We are just at a loss so if anyone has any other ideas please assist. .... GRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR RRRRR....
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Old 10-14-2007, 02:30 PM   #10
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Re: Soft break pedal

Well about the only thing you didnt mention changing is the power brake booster. And that very well could be the culprit not letting pressure/boost build.

With the car running, and when applying the brakes have someone listen under the hood to the brake booster and see if its a leaking air.

Might not hear anything, just a thought.

Hope that helps !!
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Old 10-14-2007, 03:24 PM   #11
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Re: Soft break pedal

Yah we just took the vaccume line off and it does make a sound like opening a soda and then we put it back on and pumped the break again and took it off and it still did so I'm assuming that it does not leak. We also took off the break lines from the ABS thing connected to the master cylinder and put a bleeder plug thing in it and then attached a hose w/ one end in break fluid then pumped the break. There seemed to be a good ammount of air in the thing but with it going into fluid then sucking it back out you would assume it would flush the entire thing out after about 10 pumps each line.... we did it about 100 and still seemed to get air to go into the line and then out and suck the remaining back in. Also when we took one of the cover parts off when we replaced the master cylinder the gears made a like zrrrttt sound almost like they were spring loaded. There was no way to not have this happen cause you needed to take that part off to get to the next screws to take another peice off to get to the master cylinder screws. So we put it back together after bench bleeding and put it in. We had no improvement and there was nothing worse about it. We are just at a loss so again I'll ask... if anyone has anyyyy other ideas please assist. =/
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Old 10-14-2007, 05:49 PM   #12
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Re: Soft break pedal

was thier a gasket used on the master cylinder ?
And was it replaced with a new or used MC ??

Also how are you bleeding the brakes....
are you pulling a vacum at the wheels or pumping the pedal ??

So you have checked out the abs modulator and proportioning vavle ??
You'll need a scann tool capable of checking ABS system.

This cant be that hard, realy its just brakes.
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