I have changed Master cylinder Twice, Bleed it four times, nothing but fluid comes out the pass two times. Pads are still good maybe 5,000 left on them. Brake booster is still good, with it not running press brake pedal and difference in pedal after 5 pumps on the pedal. Please need HELP, Love all of your videos Learn alot from them
Did any fluid come out of the back of the master cylinder? That isn't supposed to happen and will cause a spongy brake pedal. Did you bench bleed the master cylinder? Not doing that will put air in the system, and if your Acura has ABS, you could've gotten air in the module, which requires a mechanic to fix. I went through 3 OEM masters on my old Pontiac because of leaks at the rear of the new master cylinder.
Run the car for a minute, shut it off and press on the brake pedal repeatedly. If your booster is working properly, the pedal will progressively become more difficult to move. If it doesn't, then you have a problem with your booster. A bad booster can cause a spongy brake pedal as well.
Bench bleed both master cylinders, pump brake pedal repeatedly and no change in pedal, just like you said, Thanks for answering me