brake squeal only at hard stops and with hot pads/rotors

[gordonliu]

i have a 92 240sx coupe with z32 aluminum calipers all around, with some cheap ebay drilled/slotted rotors (5 lugs), 17/16 tokiko z32 mc (no abs), and stainless lines all around (with rear hybrids), with hawk hps pads.

the brakes are excellent, except that everytime they get hot like after repeated hard stops, i begin to hear a squealing/grinding (not like hardcore metal on metal, just a more accurate description of the noise) noise comming from what seems to be only one of the wheels. there is no problem braking whatsoever.

one of my mechanic friends told me that because all of my components except for the used calipers are new, that it is most likely because my calipers are not applying enough force on the rotor and so are allowing it to slip at higher temperatures. im trying to figure out if i need to source a new caliper, or if i have some other problem.

thanks

[rotorimp]

take the caliper/s off at the corner that seems the most likely to be the source of the noise. You may have a bum pad or something embedded in the friction lining? what ever it is it need a closer look.

[yokota180sx]

sometimes brakes squeak...its just part of performance systems

[gmorley]

some performance brakes always squeek. when engineering performance brake components, it makes more sense to design good stopping power than good noise reduction. oem brakes have a lot of noise supression designed into them, at the expensive of stopping power.

[dkdeleon68]

When you installed your brake upgrade did you replace the brake booster with the Z32 brake booster? if you didn't you should, it will stop the slipping of the rotor and stop you noise problem.

[gordonliu]

From what i have read the only real benefit to the booster has been improved pedal feel. while i can certainly see how that would be an advantage, i am specifically referring to something that happens at FULL brake force.

i have the master cylinder though.