Came back from work today and heard noise under the hood, popped the hood and ABS actuator motor was running without a key in the car. It is not my daily car and it parked there for 3 days, the ABS pump is super hot, i would guess it's running for couple hours... I think it's most likely the ABS pump is bad, but it might also be the electronics issue, which i hope not...

 

That's what mine did too. I pulled the ABS fuse and used pads to bias the brakes (XP10 in the front and OEM brembo in the rear feels OK to me). It took me a few sessions to get the feel of the brakes but it wasn't as bad as I thought it would be.

 

killed abs and getting better w/o it after couple track days. i swapped caliper last week and had a spongy brake pedal on track yesterday, first half way down has no brake, it's harder to modulate the pressure, ended up locking the wheels 2-3 times, had a flat spot on the passenger front tire. Tire still have many tread, but not sure if i can keep using it or have to replace two front tires, any idea?

 

Does it vibrate? Should be alright if you didn't do too much damage.

 

yes very obvious, I took it off and rolling on the ground, can easily feel it. I drove it the last session, didnt feel anything wrong except vibration.

 

Do a burn out to even it out

 

 

I've had this problem. It's a sign of a failed ABS module (the black plastic thing connected to the nice silver machined ABS actuator). For now, I recommend you disconnect the harness, and either get the ABS module repaired, or find a replacement module/actuator at the scrap yard. I had this company repair my module: http://www.modulemaster.com/

Service was excellent. You will need to remove the hydraulic lines and split the module from the actuator. It's a 2 banana job.

 

Thanks! confirmed my thought. I have a spare one, but probably just run w/o abs.

 

New issue is coming up, brake is always giving me troubles… This time is spongy pedal, weird thing is sometimes I can feel the resistance when the pedal is half way down (test on the street), but suddenly the resistance goes away, and it comes back up when the pedal almost to the floor. I bleed fluid two times, used half bottle of ATE. Is this possible air in the master cylinder?

 

Only if you installed a new one or you let the brake fluid reservoir drain too low (allowing air into the chamber through the reservoir). Did you have your harness unhooked when this happened? The behavior you described is strange; especially when the pedal comes back up. It now sounds like a problem with the brake booster.

 

I swapped the front calipers, but fluid was maintained higher than low level on the reservoir. Which harness do you mean? it's not pedal comes back up, it the resistant feeling. This is not happening all the time, it's random but pretty frequently.