I done the check valve an booster thing checks out fine my brake cylinder was leaking so I replaced it an my brakes worked fine.didnt lock up at all for a while until yesterday til they locked up again. When I press the pedal to hard they lock up an the pedal sticks too.

 

Wow, that's a new one for me! I've never heard of brakes sticking so badly they auto-locked. The rear drum brakes have a couple possibilities for locking up, or suddenly grabbing randomly as you described. The backing plate under the drum has contact areas that the brake shoes ride on as they expand to contact the drum. If they weren't lubed properly (extremely common), the metal on metal contact can actually wear the backing plate and make a ridge or trough. This can cause the shoes to get trapped in the trough and suddenly grab when the hydraulic pressure is sufficient to force it out of the stuck position. I learned to drive on a 62 chevy half ton pickup with 3 on the tree, and that was one of its quirks. My dad hated mechanic work and never did any maintenance on it. But the symptoms you describe sound similar. Could be totally wrong, but it may be worth pulling the drums off to inspect for wear. Second issue is the retracting springs can get worn and wear the backplate and cause sudden engagement too.

 

so if I replace all my brake springs on both my drum brakes will that solve my problem. I had my drums off one time an my shoes looked good.

 

I don't know that it will solve the problem, but if the backing plate has badly worn areas that prevent smooth brake shoe movement it could be contributing to the problem. Nothing short of careful inspection of all of the brake system will help understand the problems, and point you in the direction to solve it. If you're able to disassemble the rear brakes yourself posting pictures would be helpful. If you don't have someone experienced enough to help you and you aren't comfortable doing it yourself you'll need other resources, professionals. I've done brakes for 40 years, they aren't that complicated to me. But making mistakes with your braking system can be deadly!

 

this is true ii done a,few brake jobs an I am not afraid to ask for help if I run into something I don't understand. I much rather do disk than drum brakes lol. If i dont slam on the brakes they don't seem to want to lock up. So when I see I need to stop Im easy on mashing on the pedal.i allow myself some distance before stopping.

 

I sure hope you can figure it out soon! Any icy roads in your neck of the woods? Icy roads+locking brakes=pucker factor of 100%

 

no bad weather yet if we get something it's usually round last part of Jan roun feb. When I get the funds I will replace the backing plates an go frm there. Until then I just have to baby it round which I do anyway. Lol.