Binding brake calipers
 

The other day it was around 90 degrees and I went through a lot of stop-and-go traffic. By the time I got home, my brake pedal went all the way to the floor and other than my emergency brake, I had no brakes!:eek: Once in my garage, I walked around and touched all four wheels (not tires) and they were all very hot. I then took off the wheels and I couldn't rotate the hubs at all. I let the car cool down for about an hour and then pressed the brake pedal and it was fine. Not until I used a rubber mallet on the hubs could I then rotate them. What could've caused this? Are my calipers shot? If so, should I invest in new ones or rebuilt ones? By the way, after using the mallet on the hubs, they turned easily but once I pressed the brake pedal, they would bind again. It's almost as if the pistons are getting stuck.

Yes, the pistons are definitely binding in their bores. New calipers are not much more than rebuilt ones. Go new. What most likely happened to your calipers is the dust boots were damaged and let moisture and debris into the caliper bore itself. This occurrence damages the seal and ruins the bore and/or piston.

There are companies that can rebuild them for you (http://www.whitepost.com/brake.html), but i'd go with the factory stuff anyway.

Brakes are the most important system of your car, so be sure to inspect all components (lines, master cylinder, calipers, pads, rotors, fluid) and get the entire system in like new working order!

That's really strange that all the calipers were stuck, I've never heard of that. How is/was the brake fluid level? How old is your fluid, more than a year or 2? What about your brake lines? With such a major failure I would go through the entire system; new rubber lines, unless the are recent, flush with new fluid and check calipers condition, rebuild if required.

You can rebuild calipers yourself if so inclined, the kits are very cheap.

Your brake lines are acting in a one-way manner due to internal disintegration and not letting the fluid return to the MC. I would replace them if you have no history on them.

At the same time, repack your front wheel bearings after putting a weather eye to the grease and races, just in case, due to the heat you have generated. And, in a as-long-as-you're-in-there, you might replace the rotors as well since you'll have the hub off.

But of course, with the hub off, the calipers become a core item you can trade for a rebuilt set should that be something you need (or want) to do. Then of course there are the pads, now possibly heat-treated, that you might replace as well.

Sky's the limit! I replaced all of the above and my brakes are a thing of beauty. I'd recommend this job, and I would also recommend you rebuild your calipers yourself: two cans of good caliper paint (I like silver) and about $30.00US for rebuild kits that will cover all four units.

Finally, get flare wrenches for the brake lines since you should not touch them with any other type of wrench.

Good luck!

John

Your profile shows a ’77 Targa. Sounds like you boiled your brake fluid & that finished off your rubber brake lines. As the rubber ages it can constrict after you take your foot off the brake & trap the fluid in the calipers, keeping the pistons from releasing. After reapplying the brakes, if you can’t rotate the hubs, push the inner pad back w/a screwdriver. If it moves w/o to much resistance the calipers are probally OK, but may still need rebuilding. Replace the brake hoses (if original they’re 25 years old!) & rebuild the calipers. I just did this on my SC & the kits w/less than $20 each, new calipers were $400 & rebuilt ones by someone else was $200. Finish the whole thing off w/ATE fluid.

Jdub and david are right on. Lines are most likely garbage if they're original. OEM rubber replacements are relatively cheap and a must-do.

Just be careful with the rebuild of the calipers. When in doubt, you should probably replace the calipers or have them sleeved (same cost as new, so why not do new and reduce the margin of error) if the bores look bad when you remove the pistons.

Yep, the rebuild kits are cheap. Just set aside some time if you're a first timer. Be careful getting those pistons out with compressed air. Especially if the pistons are binding. I had to jack up the pressure to about 80 psi to get one of those suckers out. When it let go, it came out like a rocket. Be careful! Dust boots are kinda fragile too, so take care reinstalling those.

Good luck

The very first, simple check is to make sure your brake pedal is returning freely. It binds due to wear/rust and/or broken return springs. The next place to look is the master cylinder assembly. The chances of four simultaneously binding calipers are about zero. But if you want to spend thousands?

I agree with Hladun. The chance of all 4 calipers having the same problem at the same time is about zilch point whatever.
Sounds like the pressure is staying on and not returning to the m/c.
Check the m/c first.
Doubt you could boil the brake fluid to the point of damaging rubber hose, much less all 4. Doubt that all 4 calipers would need rebuilding at the same time. You normally have a problem with 1 caliper and do the other side of the axle at the same time. If you are looking for something to do you would rebuild the other 2 at the same time.
If you don't know when the rubber hoses were replaced now is a good time to do that. If even one of the hoses is deteriorating you want to throughly flush front and back circuits with cheap brake fluid and then fill with ate blue/gold.

Thanks for all of the reponses guys. I flushed the entire brake system out with new fluid about two months ago and they have worked great ever since until the other day. The front calipers are binding a lot worse than the rear ones. Tweeks sells rebuilt calipers (front/rear) for $99 that have a 30 month warranty. New calipers are over $300 a piece! I will definitely replace the brake lines/pads/wheel bearings as well since you guys recommend that. I have always heard that rebuilding these were very tricky so I would prefer not to do this. I have also purchase synthetic brake fluid as well.

Hold on: why synthetic fluid?
 

I seem to remember that there may be a problem with introducing synthetic into a system that is using traditional fluid. Smarter minds than mine will chime in here...

The "all four are binding" is a solid clue to the MC as the center point for the possible problem. Do I understand that is the case with your car, that all four bind at the same time? That would be important here and could save you some money on calipers, etc.

John

The car had sat for close to ten years before I purchased it and I noticed the other day that all of my brake pads were worn out. Yes, believe it or not, all four do this until I use the rubber mallet on them. Then, they turn freely.

I think we have our answer.............

10 yrs.??? Four can bind at once in this instance!

While your car may have sat for 10 years and some things rusted and corroded the chances of all 4 calipers "binding" at the same time independantly is slim to zero. Not that you should inspect and maybe replace some components in the lines and calipers and maybe new pads too. I'd be seriously looking at the master cylinder as the key problem. It's the only common component that would affect all 4 calipers/brakes at the same time and if it failed to release after you remove your foot from the brake pedal they will certainly stick.

Dan O
'84 3.2 Targa

I finally took off the front left caliper and the pistons are seized and the seals are practically gone. I will order all new ones and redo everything. I don't disagree about the MC being suspect, but why would hammering on the calipers with a rubber mallet cause the MC to "unbind" the caliper?