Intermitent Brake Seizing Problem

[ECV Jeep]

Looking for some advice.

My front brakes (disc with 11 inch rotors) experienced some seizing coming down 330 yesterday. I was light on the brakes coming down, but I noticed that when applied they pulled hard to driver. At bottom of the hill I stopped, and was greeted with lots of smoke from the driver front brake....so much so I grabbed the fire extinguisher just in case. No fire.

I then tried to drive Jeep off the off-ramp and noticed that the front brake had seized up. After weighing my options, I decided on a trailer to get home.

Today I pulled the calipers and both came off easily. Pads and rotors are pretty new (6 months). I found no unusual wear, but noticed that the seizing problem no longer existed. I cleaned and reassembled, and re bled brakes. Everything seems to work just fine....problem is, I didn't fix anything.

What should I do? Drain brake fluid and refill? Replace caliper? Check diaphram or proportioning valve? I am at a loss, and many here seem to know much more about this stuff than I. I can turn a wrench okay, but I am a banker not a mechanic. Your advice would be appreciated.

I like to keep my Heep mechanically sound (it ain't pretty), and this is not something that I am comfortable leaving unattended.

[Roger]

I think the best thing you can do is drop that old CJ of yours off in my yard and go buy a new one.

No need to thank me, I'm here to help - that's what I do.

(Oh - and sign the pink slip for me)

[aw12345]

There are a couple of things to check, the first thing would have been to open the bleeder screw after things cooled down if there was a lot of pressure in the caliper and the wheel turns easy after than you have a collapsed/ restricted brake hose. Just make sure everything is not flaming hot when you do that brake fluid burns very good.
If that does not free the brake then its time to rebuilt the caliper which you should do anyway.
Any caliper with the phenolic/ plastic pistons is junk after overheating/brake fade it destroys the piston. Unfortunately with late model brakes it's not a good idea to use steel pistons since this will overheat the brake fluid even faster, is the main reason they use the phenolic pistons

[RAT]

There are a couple of things to check, the first thing would have been to open the bleeder screw after things cooled down if there was a lot of pressure in the caliper and the wheel turns easy after than you have a collapsed/ restricted brake hose. Just make sure everything is not flaming hot when you do that brake fluid burns very good.
If that does not free the brake then its time to rebuilt the caliper which you should do anyway.
Any caliper with the phenolic/ plastic pistons is junk after overheating/brake fade it destroys the piston. Unfortunately with late model brakes it's not a good idea to use steel pistons since this will overheat the brake fluid even faster, is the main reason they use the phenolic pistons

Art is bang on. My front passenger locked up the same way. Just rebuild the calipers with new phenolic pistons, or get reman ones from Napa (or your parts store of choice). Once that piston gets heated up to siezing point it's crap. Check the seal on the piston before you take the old out. I found mine has a tear and allowed water/debis into the caliper.

[ECV Jeep]

Thanks Art & Kurt....looks like I will be doing a bit of a rebuild job on the caliper(s). I assume that just because only one seized, it is probably still better to rebuild both...so I guess that is the direction I am headed.

I will let you know how it goes, and post up any questions I get along the way.

[aw12345]

Before you tear it all apart stomp on the brakes hard with the engine running several times and then crack the bleeder screw, just to make sure there is no residual pressure in the caliper. If that is all happy rebuild the caliper. When you rebuilt them stick a piece of wood in the caliper when you pop the pistons out with pressurized air or that thing will go flying. To seat the dust boots around the pistons use a rubber tipped air nozzle to blow a bit of air in the caliper when trying to get the boot around the piston makes it a piece of cake

[Elusive]

also, check the caliper pins. Sometimes on older jeeps they get grooves worn in them and cause hang ups.