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Brake problems...

959 views 5 replies 2 participants last post by  gemini86 
#1 ·
ok, I got myself in a jam and need some help getting out...quick....like this weekend.

One day whilst driving home from school my brakes decide to go out... the pedal goes down to the floor and the car only slows but doesn't stop completely... I jam on the e-brake and limp it into a gas station to ***** the situation. all I could figure is that I needed brake fluid so I topped it off with whatever I had...ATF. Yeah I know prolly not a great thing to do but it got me home safely. Now all the sidden my front brakes lock up and there's no play at all in the brake pedal... Like the line is presurizing itself! I'm draining the brakes right now and I'm having troubles getting the brake lines off the caliper...but that's another story.

My question is, would ATF expand so much that it would lock up the brakes? And if so, why weren't my rear brakes locking up? What would cause the brakes to pressurize and not release?

Thanks in advance....
 
#2 ·
brake problems

Atf will cause the master cyl and disc -wheel cylinders rubber parts to expand and cause lock up- just like brake fluid will do to an automatic transmission. You will probably have to replace all parts- and bleed the system completely to clean it out. There is a slight chance that both front brake hoses could have anurisms(sp) but that isn't likely. The quick test would be if the brakes are locked up - open the bleeder valve on one of the calipers and see if there is pressure there- if so then the wheel will turn freely until you hit the brake pedal again. I had a customer put atf in his mastercylinder once- I had to replace the master cylinder as it locked up so tight you couldn't get the brake pedal to move or get the piston out of the mastercylinder to rebuild it .
 
#3 · (Edited)
I've bled the front brakes out dry and I'm trying to put new fluid in, unfortunately you're right and the master cyl now wont pump the new fluid into the lines.... only a little gurgling and bubbles coming out the bleeder. I'm having a hard time finding a rebuild kit for my car. Looks like I'll have to borrow a car for school till I get either the master cyl or the rebuild kit... :( I know never to do THAT again...

Edit: one more question, what all do you think has been damaged in the system?
 
#4 ·
brake problems

The master cylinder is sometimes a stinker to bleed- I assume it's a dual ( two compartment ) -make sure both sections are full- with the bleeders closed-- have someone just barely bump the brake pedal while you look at the master cylinder with the top off--- be careful they don't pump the pedal or fluid will squirt all over usually straight up . You don't want the brake pedal to move over 1/2 inch---you should see bubbles coming up out of the ports in the bottom of the master cylinder-- that indicates it is full of air and needs to be bled -- if it is full of air it can't pump fluid to the calipers--as the air just compresses. If you know someone with a pressure bleeder that is the best way-- a rebuilt master is the best choice--they usually come with a set of plastic fittings and short hoses with instructions on bleeding the master cylinder. Be sure not to let the mastercylinder run out of fluid or you will have to start all over .
 
#5 ·
Well, the master is trashed... I got a replacement and I'm in the middle of installing it. I also noticed that the seal in the brake booster is slightly damaged... That would make the brake harder to operate, correct? It's been this way all along and I can't find a replacement seal anywhere, and don't have the money to replace the booster. (i didn't even have tho money to replace the master either but I had to!) I was wondering if the pistons in the calipers or brake drums would be bad also? I guess I'll have to find out!
 
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