Ok here's the deal.

Car is running and u hit the brakes n pedal doesn't come back up unless u physically pull the pedal back up.

I replaced the master cylinder and same thing still happens. I'm pretty sure the booster is shot but I also need to replace the driver side rear caliper which has a stuck piston.

Is it def the booster that is keepin the pedal from returning or could the bad caliper have somethin to do with it

 

Either could be contributing to your problem. Be sure to bleed the lines properly after you replace that caliper.

 

I think I'm gonna fix the caliper first, see wut happens then if it still does it get the booster

 

Is the seized caliper leaking?

Did you bleed each caliper/wheel cylinder after installing the new master cylinder?

 

I bench bled the master cylinder, and then after installing it I bleed each caliper. No air everythin bleeds fine. Caliper that is seized doesn't leak. The piston is jus not moving

 

I'm not sure what symptoms indicate a leaky booster. I've never dealt with one. Realize that it's just a vacuum canister/chamber though. If yours is bad, I would think that you would have a vacuum leak and resulting high/fluctuating idle.

I have dealt with a seized caliper, and it did screw with the pedal travel and position somewhat, but not how you're describing.

 

I tested the booster by starting the engine n then shutting it off and pull the vaccum line off the booster and its didn't make the hissin noise like its releasin vaccum out of it so I'm pretty sure its not good

 

also when the car is is off and you pump the brake pedal, after about 3 pumps it gets solid and stays at the top, but the second you turn the car on and hit the brakes it stays depressed