Help! Right rear caliper Locks up

[bhickmott]

1977 L82 4 speed - Problem developed today while driving. Right rear caliper drags pretty bad to the point that you can't turn the right wheel by hand. Disconnected the brake line at the caliper and as soon as the fluid pressure was released the caliper works fine. All pistons are free. When I step on the brake with the engine not running, no brake fluid squirts from the disconnected line. Normally the brake pedal should go to the floor, but this does not happen. If I start the engine and step on the brake some fluid does come out, but very minimal given the totally open line. I'm assuming this indicates that the brake booster is functioning and that there must be a blockage in the brake system somewhere. My first guess is the Master Cylinder. I don't believe 77's have a proportioning valve anywhere other than the brake fail sensor that the front & rear lines from the master cylinder run through before continuing on to there respective calipers. ANYONE HAVE ANY THOUGHTS before I start tearing things apart tomorrow ?

 

[gmjunkie]

1977 L82 4 speed - Problem developed today while driving. Right rear caliper drags pretty bad to the point that you can't turn the right wheel by hand. Disconnected the brake line at the caliper and as soon as the fluid pressure was released the caliper works fine. All pistons are free. When I step on the brake with the engine not running, no brake fluid squirts from the disconnected line. Normally the brake pedal should go to the floor, but this does not happen. If I start the engine and step on the brake some fluid does come out, but very minimal given the totally open line. I'm assuming this indicates that the brake booster is functioning and that there must be a blockage in the brake system somewhere. My first guess is the Master Cylinder. I don't believe 77's have a proportioning valve anywhere other than the brake fail sensor that the front & rear lines from the master cylinder run through before continuing on to there respective calipers. ANYONE HAVE ANY THOUGHTS before I start tearing things apart tomorrow ?

The rubber line is deteriorating and restricting fluid flow both directions!
Flush steel lines and replace all rubber brake lines! $ well spent,If you just replace the one thats bad,You'll just be replacing another some place else next month!~!!

It's a purdy common occurrence on All older cars!

 

[bhickmott]

Thanks for the tip !

Thanks for the quick reply. Just went out and sprayed PB Blaster on the fittings and will pull the rubber lines tomorrow morning. I replaced all the brake lines and calipers with Stainless 25 years ago when I bought the '77. Replace the master cylinder as well. First problem that I've had with the brakes ever since. Thanks again. Will let you how it turns out.

 

[bhickmott]

Problem Solved !

Well after a little twisting, turning and heat I finally got the right rear hose out ! AND ... Wallya ... as you said, the hose was packed tighter than a Bull's A** in fly season ! I ordered a 4 hose stainless set today from ZIP along with a couple rear caliper lines. Will install next week. Vette is in the air (on the lift) till then ! Thanks again for the tip.