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Discussion Starter #1
Okay so here is the problem...
My car sits at my house while I'm away at college and recently my dad took it out and while in a parking lot (thank god) the brakes locked up on all four corners he had it towed home and eventually the brakes let go and they rolled it into the garage. Even though the brakes let go, the peddle still wouldn't budge an inch!

After reading up on the problem on the net (there isn't a lot of people with this problem apparently) I decided it must be the master cylinder, so I went to autozone today and bought a replacement. I bench bled it as it said to and re-attached all lines. Then I had trouble getting it onto the firewall and it wanted to push fluid out as i pushed the master cyl. onto the firewall and plunger rod from the peddle. Now even with the new master cylinder on the peddle wont budge more then half an inch!!!

Anyone have any ideas? I havent tried bleeding the lines from the drums yet and will probably try this tomorrow.

In case any of this matters... Its an auto, a coupe, and has drums all the way around.

thanks in advance!
 

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The master cyl. plunger should not be depressed at all when it is attached to the brake pedal and the pedal is at rest. Something is preventing the full travel of the brake pedal.
 

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Discussion Starter #3
thats what I was thinking, I checked the depth the plunger should go into the master cylinder on both the new one and the old one and they were nearly identical, the new one actuall was slightly deeper (1/4" or so). I'll check to see if anything is causing the brake peddle to lose its full range of motion...
 

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Discussion Starter #4
So... just got out of the garage, heres what i found -

when I remove 1 drum and push the peddle, it moves freely as it should, I assume this is because all of the pressure within the system is being diverted to that drum because the fluid is taking the path of least resistance, but it doesnt help my problem because as soon as I put the drum back on I am back to square 1 with the peddle not traveling more then 1/4 inch before becoming rock solid. I'm thinking of adjusting the rear drums to give them more room to travel but I'll wait til i hear back from someone on here. Thanks!
 

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Discussion Starter #7
Well I pulled the drums on the back which I suspected to be the problem and one of the drums was wayyy out of adjustment (pads pushed out too far), I adjusted it to match the other side and I believe that fixed the problem. I drove it up and down the street 8 or 9 times and did some 25-0 stops with no drama and the pedal returned to normal position and the brakes didn't stick. Thanks for the help!
 

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How in the world would the wheel turn at all if the adjustment was too far out. It apparently had the correct adjustment when it was driven before. This would make me suspicious of the wheel cylinders. I think that since the car sat up, moisture from the atmosphere has gotten absorbed into the brake fluid. (This will happen during normal use. Sitting makes it worse.) This creates a fluid that's corossive. The contaminated fluid has corroded the pistons in all four of your wheel cylinders. They are now binding in their cylinders. The pistons are made of aluminum and will corrode pretty badly and easily if not used for a while. When the car sits, obviously the brakes are at rest. The pistons corrode in the wheel cylinders in that position and that would explain the hard pedal. After pressure has been applied, apparently the pistons moved and wouldn't retract, causing the wheels to lock up in all four corners. Eventually the spring pressure pushes the pistons back far enough to allow the wheels to roll. You will experience a hard pedal if the pistons don't move freely and easily. Replace the wheel cylinders and thoroughly flush out the brake system of the contaminated fluid. The cylinders are very reasonably priced and definitely worth your life and others.

Check the emergency brakes for binding cables, too. A binding cable can make a rear brake seem as if it's adjusted out too far if it, (Emerg. Brk.), has been applied recently and the cable didn't return to its unengaged position.

Please don't drive your car until you are 100% positive that the brakes are working like they should. Don't make assumptions on the condition of your brakes. There are problems with the brakes and what you have done isn't the repair.
 
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