65 Brake Seize - Caliper?

[Earle Downes]

Re: 65 Brake Seize - Caliper? MORE HELP PLS

I laid awake last night trying to think of what I was missing. An important fact came to me. The seizing doesn't come immediately after applying pressure to the pedal. It comes 1/2 to 3/4 mile down the road, with the pressure building gradually. At first it seems like the engine is just losing power, then it builds to the point where the engine can't overcome the brakes. Remember, it's only the rear brakes.
My first thought was the M/C, but only the rear brakes are affected. Then I thought about some form of heat buildup near the lines, but I haven't done anything to, or around, the brake lines.
Any additional ideas or opiinions would be very welcomed.

[Larry Sherman]

Re: 65 Brake Seize - Caliper? MORE HELP PLS

Any chance the master cylinder was rebuilt and had check valve installed in outlet as in drum brake master. Just fishing. Larry

[Earle Downes]

Re: 65 Brake Seize - Caliper? HOLD FIRE

Hey guys, I went after the only remaining thing I could think of.... the caliper bores. As Kieran had suggested a number of times, there was 'debris' caked on the bores. Not much, it cleaned right up with brake cleaner and my finger, but it was probably enough to restrict correct travel of the pistons.

Stay tuned, I'm doing all eight rear pistons/bores and I'll let you know the result, hopefully by tonight.

[Kieran A.]

Re: 65 Brake Seize - Caliper? HOLD FIRE

Earle,Two more thoughts came to mind after reading your last post....First,and I am sure thought of this,when blowing out the rear line use one of the old hoses sealed with a Vise-Grip connected at the junction block on the left rear trailing arm to ensure good air pressure through the line going to the right rear caliper. Second,if the rears have that much debris in them,the fronts are most likely in the same shape. Brake system clean and repair seems to be one of those areas where the "shotgun" approach is warranted.Let us know!Kieran #11373

[Earle Downes]

Re: 65 Brake Seize - Caliper? NEXT STEP

OK, so I bought 8 replacement caliper seal kits for the rear and got ready to do the business. Replaced one, then remembered something Joe Lucia had said in an earlier post about 'if the gold anodizing is gone from the piston to bore land, replace the pistons'. Luckily, I only wasted one seal kit before I remembered. My lands on the two pistons I removed not only had the gold gone, but actually had grooves and pits in the lands. So I just ordered two 'vette brake' o-ring piston kits (pt# 11310) which will give me new o-ring pistons and the full seal kit.

The weird thing is that although I believe the caliper/piston situation is the issue, I'm still not completely sure what's causing the pressure buildup while driving. I'm hopeful, but not completely sure.

I'm a-hearin' Kieran about the fronts, but like most people the economy brings me to a 'make sure it needs it' attitude.

I'll keep y'all posted, but won't know much 'til the middle of next week after the new pistons arrive from vette-brakes.

Thanks so much to everyone for your input and help! When I'm finished, I'll do a debrief on what I went through.

Earle

[Terry M.]

Re: 65 Brake Seize - Caliper? NEXT STEP *TL*

I understand economics, but brakes are a poor place to cut corners. Please reconsider and at minimum disassemble the fronts for a thorough cleaning. You won't regret it, even if just for the peace of mind of knowing you did the job completely.

[Earle Downes]

Re: 65 Brake Seize - Caliper? NEXT STEP

Terry,
You're right of course, especially since the fronts are where all the action really happens. I'll probably get the rears done, relax a while and then get into the fronts shortly thereafter.
Thanks for keeping me honest (and safe).
Earle

[Robert W.]

Re: 65 Brake Seize - Caliper? NEXT STEP

While waiting on your parts, disconnect the tubeing at the block where the front and back split and also where the two rear split and make sure you don't have "floating" debris that is working as a check valve at the block. While you have them disconnected blow out those sections of line.

[Earle Downes]

Re: 65 Brake Seize - Caliper? NEXT STEP

Good idea! I've only blown them out from the M/C backward.... wouldn't hurt to reverse the process for a sure clean.
Thanks!