Just got my first Tribute (2001), has the hissing brakes issue but surprised to find 95% of the noise could be avoided by un-hooking the booster boot inside the footwell.

Looks like the noise comes on as the boot becomes less tight on the booster in service allowing the air inflow to hiss/whistle through the boot join onto the booster.

Step 2 will be to see if tie-wrapping the boot in place also reduces the noise (it should do)...

Much easier/better/less $$$ than replacing the booster...

FYI the boot has a vent system with a foam filter around the pedal pushrod end so it is designed/expected to flow air through it, it seems it only hisses when the air can pass through the boot-to-booster join...