No Brake Pressure?

[RPurdy]

Alright so I have no brake pressure all the sudden? Like my truck still has brakes and they work so I know its not the master cylinder. They just have no stopping power. The pedal sinks to the floor like I'm pushing it through jello. And I'm incapable of "slamming on the brakes." I can bring the truck to a stop but I have to push the pedal down to the floor to do so.

I want to say its the brake booster but the booster went in my 97 Jetta and I still drive it fine with manual brakes. Replacing it is easy enough I just want to be sure that is the problem before I replace it.

Also I'm having this problem with my 92 IDI. I'm pretty sure they're the same setup as my 95 but not 100% sure.

[car23]

check your vacuum pump that works the brakes

[madpogue]

FIRST thing to do is look for fluid leaks. Check along all the lines, outside the M/C, the ABS block down on the frame, the wheel cylinders, the calipers, etc.

If no leaks visible, then actually it is likely it's the master cylinder. It can leak internally on either the front or rear piston. If it were the vacuum pump, you'd be more likely to get a too-hard pedal.