Chevrolet Repair: 99 chevy tahoe, chevy tahoe, fluid leaks

Question
brake pedal goes to floor. but it still seems to stop ok. changed front brake pads checked rear brakes their ok. bleed brakes. changed out master cylinder, no change in performance.is it the brake booster? it happens cold or hot. also changed out the check valve on the booster. there are no brake fluid leaks

Answer
Hello Steve,  I haven't seen a pedal go to the floor on this truck unless the ABS system activated at SLOW speeds. Less than 10 MPH.. Is the pedal ok at higher speeds and then when the truck gets down to around 5 mph it goes to the floor? If this is true then the abs front speed sensors need to have the mounting surface cleaned of rust. To do this you remove the front speed sensor from the front wheel bearing,now file the rust off the mounting surface.

      If the truck has a bad pedal even at higher speeds then I would have to say you have a problem in the ABS unit. The booster can't make the pedal go to the floor and you say there are no leaks and the master cylinder is new. Only thing left is the ABS hydrualic unit.

Hope this helps you

Mark