first of my break pedal goes right to the floor.
When i step on my breaks, i hear something like air

I think its my master cylinder,
and other ideas?

thanks guys

97 chevy c/k 1500

 

Might be a stupid suggestion but ive had something similar happen in my old cavalier, broken brake line, no fluid so its basically pressureless. Check your brake fluid to vito this possibility

 

No broken break lines, i checked when i did my breaks..NO LEAKS
fluid looks good just black.

no i dont know if its the brake booster or Master cylinder, any way to pin point that out

 

brake pedal goes down to the floor + hissing noise= leaking booster diaphragm. diaphragm can be serviced seperately or replace booster.
otherwise, brake fluid level will be lower than it's supposed to be and you'll have obvious signs of brake fluid leaks somewhere.

 

ok, here it is from a book:

1. depress the pedal and start the engine. if the pedal goes down slightly, operation is normal
2. depress the brake pedal several times with the engine running and make sure that there is no change in the pedal reserve distance


airtightness check

1. start the engine and turn it off after one or two minutes. depress the brake pedal several times slowly. if the pedal goes down farther the first time but gradually rises after the second or third depression, the booster is airtight.
2. depress the brake pedal while the engine is running, then stop the engine with pedal depressed. if there is no change in the pedal reserve travel after holding the pedal for 30 seconds, the booster is airtight.

i am not the one who wrote the instructions.

 

thanks,
i will check it out and post it up