Hello,
I have a Lancer evo 4 gsr, pretty much converted to RS, no ABS, It has the RS brake proportioning valve, Who i think Is the problem, when i start braking lightly i hear (the squeal) only the front right brake, if i put more force Will brake normally, but Is the third time i warp front disk (Always the FR).
​​​​Is It possible that i have something wrong with the brake proportioning valve?
Brake pump Is new, front calipers are rebuilded.
Someone had the same problem?

Sorry for bad english and thanks you

 

Sounds like you need to rebleed them. Make sure you do both sides of the caliper one at a time,

 

Did you check the pads on that rotor? Are they wearing evenly or are the pads slanted?

 

I'll give you a bit of background, 1 year ago i had a weird problem, basically when i pressed the brake pedal the front right caliper remain closed, locked in Place, i find out later that It was the pump, changed It and It worked well (rebuilded both calipers too) but Always with this problem on the FR, last year i tried 3 brake pump (2 used, the current brand new).
Is like there Is Always more pressure on the FR and After It It goes to the other 3, the first thought Is that the FR Is the closest to the brake valve, but still, It shouldnt act like this. Bleeded It like 7 times last year, can try another time, but im not Sure thats the problem.