I have a 1994 honda accord and a 1995 honda accord with the same problem. I was driving the 94 and the brakes locked up on me, so I changed both calipers. When it lockeed up on me again I started driving the 95 and now its doing it. What's next? Porpotion valve? Master cylinder? Brake lines?

Try this:

. Completely change the brake fluid.

. Remove each caliper, wipe each caliper pin (2) off with a rag, and lubricate with silicone grease.

If the problem persists, the calipers may need rebuilding or replacing. Changing the brake fluid every 2 years, like Honda recommends, is the key to long, trouble-free brakes.

I done that so far but the problem still exists

If you used top quality pads, then I would focus on the master cylinder. I assume neither of these cars have ABS.

Yes they both have abs

My wife got rid of her 1994 Accord EX because of ABS problems. Honda is well aware of these issues. Repairs ran around $2,000. Instead of the master cylinder, I would begin checking out the ABS. See if there's fluid in the separate ABS reservoir.

Any other sugestions I'm desperate

What exact brand and type of brake pads did you install? Do not use semi-metallic brake pads--only organic or ceramic.