it is hissing because there is a vacume leak in the brake booster it will require a new brake booster
Sounds like the power brake booster is bad. Get it checked out.
I'd check for faulty Brake booster. I've seen cases of them cracking. I'm pretty sure their all made of plastic, the falcon boosters.
it is located to the right of the brake pedal
Adjust the brake switch which is above the brake pedal.
brake light switch is above the brake pedal
on the break pedal itself if you look under th edash youll note a plug going onto it that's the switch / sensor
brake pedal light switch.
On the brake pedal arm.
Regular DOT3 brake fluid
Just above the brake pedal on the pedal shaft.
DOT 3 is the fluid for you.
to remove the pedal box the whole dash has to be taken out, absolute pain in the ass