1990 Ford Ranger

The breaks on this truck became very weak and the petal would have to be pushed almost all the way to the floor. There were no leaks and the shoes and pads are in good shape. I tryed repacing the master cylinder but this didnt help. I have had no break woring lights come on at all. Could the ABS system be causing this problem
July 28, 2006.

Could be the power brake booster is leaking vacuum somewhere, I think there are tests that can be done to determine if the booster is holding vacuum. If the pedal is going way down, i'm surprised the abs light is not on, usually if there is excessive brake pedal travel, the abs will set that code and the light will come on

Jul 28, 2006.
Adjust the rear brake shoes until there is a touch of drag. Bleed the system. You'll need to verify the correct bleeding procedure. We have has several similiar pedal problems that came back to bleeding in a particular specific way. Also, sometimes you can have a caliper or wheel cylinder that will not show leakage, but will suck air into the system.