brake noise

OK, here is a newbee that needs some help. Just bought 76 and trying to get in good shape. Previous owner had $389.00 worth of brake work done in Sept. 04. Sometimes after stopping, I have grinding, groaning noises from left rear. Sounds like rear end is about to fall out. Have also had same from right front occassionally. Feels like pads are not releasing from rotor until car starts moving. What are your suggestions. I did notice that after washing wheels, I made several stops before problem again started. THANKS!

There could be several issues here. You could have sticking calipers. Or you could have a pad compound that is reacting to the rotor surface. If it's only in the rear, you could have a parking brake acting up.
In any case the water can lube the affected parts and make them respond differently.
You just have to take them apart and take a look.

Or you could do what my youngest son said to me once when he was little,Hey dad if your brakes are squeeking why do'nt you spray some WD-40 on them ?

HA HA! Yea but I find coating the rotors and pad surfaces with automotive grease stops my sqeaking problem very well! But now my vette wont stop. I cant figure it out.

If the flexible brake hoses are still original or very old could be the problem. They can deteriorate on the inside enough to act like a check valve and not let the calipers release. They certainly don't owe you much if they are the 29 year old originals at this point anyway.

I had a similar problem on the back of my '71. The problem ended up being that the park brake shoe retaining clips had let go (probably just disintigrated over time with rust) allowing the shoes to rub on the inside of the hubs. Pulled it all apart and replaced bearings, seals and put a stainless steel kit in the park brakes (shoes were still ok). I had to do the bearings anyway and it's a good idea to do them while you've got it all apart 'cause you can't do the park brakes without taking the spindles out.

As far as the front noise goes, yeah, sticking caliper pistons, bearings, something loose or missing? Have fun 'cause the back end is very labourious but fun to do.