last night i was banging some gears in my hatch and grinded 3rd, then slightly after that, i got stuck in 2nd gear and couldnt get out of second at all. i got it home, as i was pulling up to my house my brakes went out, couldnt build up an pressure on the brake pedal unless car was off, and then i also got it to pop out of second gear. Is it the master cylinder or do you think a tranny problem or maybe both?

 

1st of all u didnt read the rules of htech. 2nd your subject line or title should not read help!!!! make your topic specific. 3rd your brakes have nothing to do with the mechanics of your tranny. and 4th your brakes get "pressure" when car is off bc brakes are powered. so therefore feels like it has pressure.
ok now as far as the brakes go check for leaks or low fluid on res. if fluid is low your brakes could b bad or u lost fluid.
and the tranny if u grind in 3rd its prob gonna grind all the time eventually. and it sounds like you neeed a clutch.