Caliper freezing up

[john.thompson068]

I have 76 Dodge Aspen calipers which I bought brand new 12 years ago. I also replaced the rotors and the rubber brake lines at the same time when I did the disk brake swap on my 66 Satellite. The last two times I drove the car the front right caliper has been freezing up. After using the brakes lightly while just cruising for a while, suddenly the car starts pulling right and the brakes pads start smoking. Later, once the calipers are completely cool they release.


Why is this happening?

 

[shag766]

air

 

[scotts74birds]

Next time this happens, crack the bleeder screw, and see if the caliper releases. I have seen the rubber brake lines collapse internally. And also hose clamps rusting and pinching the line closed. At 1000psi, the fluid will get to the caliper, but is unable to flow back when the pedal is released. You could even remove the wheel and pump-up the pedal and see if the rotor can be turned after the pedal is released.

 

[Ron 73]

Sometimes these rubber brake hoses can also get a obstruction in them, usually rust, The pressure allows it to flow thru but as said wont let it back off, and they can and sometimes do look perfectly normal.

 

[john.thompson068]

After the first time we bled the brakes for the first time in 12 years. The fluid was brown and had a lot of air in it. It only freezes once warmed up, which leads me to think there is something wrong with the cylinder in the caliper. Is there any problem with the synthetic resin plastic cylinders used in these calipers?

 

[Cranky]

You mean the pistons? They work ok if they are not worn. If the pads wear unevenly, that will usually mess them up. Brown fluid is a good indication of rust in the system and that could be a good reason why the brake is sticking. Particles can be wedged between the piston and cylinder....and 12 year old brake fluid probably has plenty of water in it by now.

 

[john.thompson068]

We bled the brakes so the fluid is now fresh. However, as cranky stated, things have started to rust inside the caliper. Looks like my only option now is to spend $215 on new calipers. The car was rarely driven for five years while I was in the service, then sat totally unused for two more years while I was in school. Guess all that sitting around gave the calipers time to wear out from not being used.

 

[1971RR]

Check your local parts store for the calipers. Way less than $200.

 

[Meep-Meep]

If the brakes are hanging up when it gets hot you may have an issue with the MC push rod length. If the rod is too long the piston can't come all the way back to expose the compensating port. Did you replace the MC? Loosen the MC bolts and put some washers between the MC and the booster/firewall and see if the problem continues.

 

[yellow68runner]

air

?????????????????????????????????????????????????????????????????? really ??

 

[Big G]

Like Cranky said, I would suspect the calipers have a rust build up, a bunch of crud from all them years (flushing the system usually doesn't get that out), or even the seal that seal the pistons to the cailper bore are hard. The AN body Dakotas had this problem, and happens alot on other cars. Brake fluid Dot3, should really be flushed every few years, the fluid absorbs mositure out of the air. Hang a reman caliper and flush the brake system you should be golden, those calipers at Advance are $25 for cheap ones, and $65 for better ones, or go old school and get the seal kit and blow them apart and rebuild them. I deal with this stuff everyday.

 

[john.thompson068]

Thanks for all the replies everyone. I am finally getting motivated to get back into the garage and get her back on the road again after a slew of problems nearly had me ready to sale my car out of frustration :angry9:.

Anyway, I was looking the price for loaded calipers, so you are right about the price Big G. I will go down and order the better ones soon.

Also, I did not replace the master cylinder or anything else to cause this to happen. It is just as Big G and others have stated.

And Shag is right also. The first time this happened, I lost pedal pressure as well as had the brakes freeze up because there was lots of air in the line.

 

[john.thompson068]

I think this is what I remember reading, but don't know how true this is. It is from someone on moparchat: "you need to have some play in the steering box or you will burn up the worm gear been there done that now im rebuilding mine you need 2 in min play in the box".

 

[john.thompson068]

What the heck? That post was suppossed to go with my other thread. Anyway, I just went to the store to order the Wagners for $60 but Wagner doesn't have any in stock so I ordered a set of the $25 calipers.

 

[green1]

Had that problem with a 79. Bakelite pistons expanded, went to alum pistons, no problems.