xanmanz31

ok so ive been working on a friends 01 is300 and recently we've noticed a random occurrence where the front brakes feel like theyre slipping and make a groaning moaning sound. it will happen a moderate pedal pressure and with heavy pressure. i realize that abs systems will slow the roll and are designed for specific amounts of slippage. in this case its almost like as youre coming to a stop the car slips on a banana peel, or like the abs is working and all of a sudden it cuts out and back in.

initially noticed while running aftermarket 17" rims and low pros not immediately after install though. damaged those and went back to stock still noticed slipping. two days ago he put on a set of 19" and said that it seemed to lessen the occurrence of slipping. i suggested we flush the system since it had never been done in the cars lifetime. now he thinks its worse than ever.


recent replaced parts:
half *** system flush since i dont have access to the factory tool for the abs system to be bled.
front pads semi metalic
front rotors oe spec
rear rotors oe spec


i dont suspect a sticking piston in the caliper bc it doesnt pull either side when braking

the booster and master visually look fine no external leaks. i thought possibly master cylinder fluid blow by from bad internals.

im leaning mostly towards the pressure modulator in the abs system. i just cant think of what wouldve caused this to start happening. my buddy and i are getting pretty frustrated.