1987 CRX DX Brake Problems

I'm having trouble with the front brakes on my newly purchased CRX. It seems that after it is driven for a while the brakes get really tight and will even cause the car to slow down a lot without pressing the brake pedal if I let off the accelerator. If I let if sit for a while, the brakes will release and everything is normal until it is driven again. I replaced the rubber lines because I thought the inner layer may have collapsed and was not allowing pressure to be relieved quickly enough but the problem persists.
Any input is greatly appreciated. :banghead:

Sounds like 1 or both of your calipers are seized. The seized brake will become really hot when this happens which will help you determine which brake is causing the problem. Don't actually touch the brakes to feel if they are hot, if one is seized it will be hot enough to burn you. Just get close enough to feel the ambient temperature, the seized brake will be noticeably hotter than the others. Also, the seized brake will usually have more brake dust around it.

The only way to solve this problem is to replace or rebuild the seized caliper. You should also check the rear drums and make sure the e-brake is working and adjusted properly.

If they were seized they wouldn't release at all though, right? If it sits for a couple hours, the brakes release. I pulled the calipers off the other day and I was able to push the piston back in with my bare hands, so I'm not sure that's what's wrong.
My first guess was bad calipers too. Let me know if you still think it's the problem.

Well I went ahead and replaced both calipers and the problem persists. I'm thinking there may be something clogging an inlet or outlet in the proportioning valve or even the master cylinder. I'm checking those next.
If anyone has any ideas please let me know.

Sounds like you have this problem under control. There's not much else you can do other than replace the MC and proportioning valve.

Almost every time I've had a problem like this it's been the calipers, except once when it was a bad brake hose.