Originally Posted by charlielin
My 2001 GS300 is making squeaking noise at random time. It starts to make noise not even starts engine. It sounds pretty quick rate and gets often recently. I don't need to press brake to hear the noise. The only way to stop the noise is to unplug the ABS wires in the ABS brake module area. Did anyone fix the problem by anyway other than replace the ABS master pump module which is about $500 used condition ? Please help. Thanks !
You won't be able to fix the brake master yourself and nobody that I've found can fix it. This item is usually replaced as one unit.
The unit is made up of
Brake master cylinder/reservoir(top center)
ABS controller and fluid module(left side)
brake booster motor(bottom)
accumulator can(right side)
The intermittent squeak is most likely the booster motor pumping up the accumulator which is low on nitrogen so it's pumping up more often than it should. It is essentially a problem that needs to be fixed. The brakes will work, but not as well as they could if this is happening. You can have this specific issue without seeing any lights on the dash.
I just replaced mine with a 2002 unit. You just swap over the sensor from the old unit with a 30mm deep well socket. It's like 60ft lbs, so it's tight. I paid like $430 shipped for mine with a 90 day warranty. Honestly, it's pretty darn easy to swap out the entire unit and bleeding the unit and brakes is easy.
process goes like this
1. install the unit and fill with dot 3 fluid
2. key off depress brake pedal 40 times
3. key on, motor will pump accumulator for up tp 40 sec. it should stop though fi it's a good unit
4. with key to on position pump brake pedal 20 times, buzzer comes on then should go off
5. check for leaks as lines tighten as needed
6. key on position bleed front right, then left caliper by pumping and holding pedal
7. brake pedal will get hard
8. bleed rear calipers by simply holding down pedal and cracing the bleeder,let some fluid out
No need to reset the ecu after all these steps and your brakes should work great if you did this properly and you have a good brake master unit.