Author Topic: Brake trouble (Read 393 times)

tce2506 · « **on:** June 01, 2006, 05:08:22 PM »

So I'm driving home from golf yesterday and my truck doesn't seem to have the usual amount of power. Then I smell something burning. So I tap the brake to turn off cruise control and the pedal only moves about a half inch. The brakes still work, and I'm close to home so I go on. When I get home, my front fenders are too hot to touch, and so is everything near the wheels. My front calipers have locked up and boiled all the brake fluid out of the reservoir for the front brakes. The master cylinder gasket is melted. Not looking good now. So I remove the wheels and check things out. The rotors look fine and the pads still have plenty left on them. I push the pistons back in and notice that no fluid has gone back into the master cylinder. So I add brake fluid, bleed the brakes and take it for a test drive and they lock up again. I'm guessing that the master cylinder has gone bad and needs replaced, any other suggestions??

GtoRA2 · « **Reply #1 on:** June 01, 2006, 05:27:17 PM »

tce2506

You prolly didnt give enough info for people to help.

What make, model and year are you driving?

On the upside the Brake systems are pretty simple and you can prolly do it all yourself. Even if you have to replace the booster hehe.

rpm · « **Reply #2 on:** June 01, 2006, 11:23:24 PM »

You have some serious problems if the calipers got hot enough to boil the fluid. It could be caused by a lot of things. Most likely suspect is a bad caliper piston not releasing. I'd replace/rebuild everything from the master cylinder down. Rotors are probably warped and the seals are definitely heat damaged.

Also think about repacking those wheel bearings.

Hangtime · « **Reply #3 on:** June 01, 2006, 11:36:05 PM »

tce2506 · « **Reply #4 on:** June 02, 2006, 04:04:46 PM »

OK,
96 chevy 1500 4WD with the 5.7 (350) V8.

rpm, Both front calipers are not releasing so that's why I figured it was the master cylinder. After I pushed them back in and refilled/bled everything I took it for a test drive. No noticeble vibrations when I applied the brakes, but they did lock up again. I like the idea of replacing everything from the master cylinder on down, but what seals are you talking about, and would that be covered with replacing the braking system. I did some checking and it's only around $600 (before returning the cores) to replace everything, sound like the way to go.

Dartman · « **Reply #5 on:** June 02, 2006, 06:22:29 PM »

If its both front calipers that lock up at the same time and only after you cycle the brake pedal then you are 99 and 44/100% assured your master cylinder pilot valve is not stroking back far enough to release the line pressure to the front. If you can push the caliper pistons back thats a good sign, did you check to make sure the caliper slide bolts aren't hanging up at the same time.

After many years of doing this type of work I always think I have seen everything, then something else appears that humbles me. The latest was an exact situation you describe except it would only happen on 1 side of the front. After much investigation I found it was the inside of the brake hose between the caliper and feed line was collapsed and holding pressure on the caliper even though you could break the connection at the master cyclinder and get no pressure. From what you describe this doesn't fit your possible problem but I throw it out there as another wtf experience.

dmf · « **Reply #6 on:** June 02, 2006, 07:01:21 PM »

My next door neighbor is a mechanic, heres what he asid.

"Replace both front brake calipers, replace the brake master cylender, replace the brake fluid, have the front rotors turned to make sure they're not warped. Replace the front brake pads. He said that much heat can warp rotors, and weaken the brake pads. He also said to check every line connection for leaks caused by boiling the brake fluid. Also check teh front wheel bearings, you might have very well burnt the wheel bearing grease, which will renender it useless. Fix it before driveing it again, or else more damage could happen or even an accident."

He works at Tread Quarters.

storch · « **Reply #7 on:** June 02, 2006, 07:04:04 PM »

Quote

Originally posted by tce2506
OK,
96 chevy 1500 4WD with the 5.7 (350) V8.

you see the problem is right here, you bought a truck from a company started by a frenchman.

buy ford next time remember First On Race Day.

moneyguy · « **Reply #8 on:** June 02, 2006, 08:06:00 PM »

locked up front brakes means nice heaters!!!!!!!

SMOKE EM UP DUDE!!!!

Flit · « **Reply #9 on:** June 02, 2006, 08:34:52 PM »

I don't see how you can boil your brake lines without Some kind of sign on the rotors and/or the pads.
Of coarse, I'm not a mechanic either.
If it got so hot you could'nt touch the fenders I would definitely replace or repack the wheel bearings.

eagl · « **Reply #10 on:** June 02, 2006, 09:15:06 PM »

Don't forget to replace those brake lines too... They're not too expensive so as long as everything else is getting fixed, replace them.

mentalguy · « **Reply #11 on:** June 02, 2006, 09:22:59 PM »

Quote

Originally posted by storch
you see the problem is right here, you bought a truck from a company started by a frenchman. buy ford next time remember First On Race Day.

You got it mixed up. Its Found On Road Dead. I could give you other ones, but Skuzzy wouldn't like it.

rpm · « **Reply #12 on:** June 02, 2006, 11:25:28 PM »

Dartman pretty much hit the nail on the head. But, there is 1 more thing that could be causing the problem. I'm not sure if you truck has one, but I had an '88 F-250 that had the exact opposite problem, rear brakes not working. Turns out there is a brake pressure balancer that distributes even pressure to both sides. Mine had developed moisture in the rear system and somehow caused the rear brakes not to get any pressure at all. After I replaced it, I almost went thru the windshield the first time I hit the brakes.

WhiteHawk · « **Reply #13 on:** June 03, 2006, 07:19:26 AM »

ummm.. i had a similar problem about 15 years ago. Check to see if there is a splitter after the master cylinder that takes the 2 lines from the master cylinder and turns them into 4 lines to go to all 4 brakes. It is some kind of differential valve that makes sure the pressure is distributed evenly. If the ports get clogged, it wont allow the brakes to open up again and poof. You are a roadside fire victim. If it is the problem go to a junkyard. the dealer will ram rod you for that part.

storch · « **Reply #14 on:** June 03, 2006, 07:20:46 AM »

Quote

Originally posted by mentalguy
You got it mixed up. Its Found On Road Dead. I could give you other ones, but Skuzzy wouldn't like it.

pffft WRONG!!! your handle easily explains why you would feel otherwise