Friend claimed brake pedal randomly went to the floor one day. I was on work travel, he brought to local mechanic. They bled, couldn’t find anything wrong with it.

I got back, noticed right away MC was leaking onto the brake booster. Paint was peeling, removed and replaced MC. Bench bled, installed lines, and then bled the two lines with my friend at the pedal. (Pump pump, loosen, tighten, pump pump)

Brakes still spongey for the first half of throw.

Bled all the calipers, RR, LF. THEN LR RF.

Dirty fluid, black fluid, orange fluid. All lines flowing though. Used the hand pump bleeder. Also used the foot pump method with my friend.

I’ve ran over 32oz of brake fluid through this car, still spongey.

Went to a dirt patch, engaged abs. Still nothing.

Took apart calipers, backed them off. Cleaned them lubed them. No sieze.

Used a obd2 tester. Was able to engage all solenoids in ABS except RF OUTLET and RR OUTLET. Those wouldn’t click on or off.

No idea where to turn next. Abs module? Can I blow air through this abs module when I take it off to clear any corrosion or blockages? Is it somehow my Booster?

Pressing the pedal fast when I’m driving, it feels almost normal. But a slow application it goes to the floor then applies at the last 1/4 throw.

2011 Mazda 3 automatic US.