ABS light comes on.... W126 Euro

[forcefed44]

I am having a slight problem with my '85 500SE euro's braking.. After 15 mins of driving, and applying the brakes coming to a stop, the brake pedal goes to the floor and the ABS light comes on. I have a squishy pedal as if there is no brakes unless you pump it.. After you shut the car off and restart after 5 mins.. Everything is fine.. and then another 15 mins.. pedal goes to the floor and ABS light comes on.. I have checked everything twice thoroughly: pads, calipers, shims, checked Vacuum connection at the booster and installed a new hard line with one-way check valve, and re-bled the brakes twice..

My question is..

1. Where is the ABS ECU located? I would like to try unplugging it and checking the brakes
2. Does this have anything to do with the MC?
3. Is this a vacuum situation? The car does have AMG high-lift cams in it aswell as major internal work..


Thanks,
Chris