Here is an issue that I am having....I have a front right brake locking up..here is what ive done...

I have changed brake pads brake Caliper....I have bleed the brakes and replaced the spindle..and the rotor...And have replaced the ABS Modual

What is going on....When I press the brake pedal to stop...the car stops...so far so good..when I release the brake pedal the plunger that pushes on the brake pads does recide like it should...it does a little bit but not very much...this is only happening on the front right brake..the other three wheels are just fine....if I press the brake again there is so much pressure built up on brake pads that they wont release...

What I can do to get around this....when the brake becomes locked up I simply pop the hood and crack open the brake line coming out of the ABS module that leads to that brake releive the pressuse to that brake and the calipers go back like they should...

Like i have said I have replaced the ABS Module thinking that was the problem...I took it to a dealership and they havent got a clue.. one person did tell me something about that the ECU or ECM or something along those lines controls each brake line through the ABS Mod...and so there fore the ECU is bad and should be replaced...now Im told that there are two in the car..one for the gas side of things and one for the electric side of things...and of course I need to know if I need to buy the electric one or the gas one...?

Any ideas or suggestions?