Power Brake Problem

[Dickie]

Just noticed today the brake pedal on my '04 CC 2500HD seems to be going closer to the floorboard than I have become accustomed to. With the engine off, the pedal depresses about half way to the floor and stops. With the engine running, the pedal can be depressed about an inch before a resistance is felt and the resistance remains constant as I depress the pedal all the way to the floor. I checked the fluid level in the brake reservoir and it is up to level and there is no sign of leakage in the engine compartment or the garage floor. Anybody else experience this problem or can diagnose?

[More Power]

See if the pedal feels any different when you're rolling. I've heard of this before and wondered if the 4-wheel ABS could be shunting pressure because it thinks you're skidding.

MP

[madmatt]

yeah Like MP said thats just normal op to some extent. The abs system is releasing pressure as if in a ABS stopping situation. I have seen some smaller cars and vans do this real bad when their mastercylinder goes out. they even get to the point where the vehicle will start to roll. I think your ok, just noticed something you haven't in the past.

[Dickie]

You guys are right. Talked to the dealer and he said it was normal operation. He guaranteed all wheels would lock up if I really stood on the brakes.

[BlackMax 2001]

Mine has the same feeling and I was told the same thing by the service manager where I bought my truck. And he is right. When you need them, they will work. First hand experience. Danged bicycles! :mad:

[More Power]

Back several years ago, one of our members had a 1993 6.5TD K2500 with RWAL (rear wheel anti-lock brakes), and his brake pedal would also go to the floor when stopped. The dealer replaced the PS pump, the hydraulic brake booster, and the brake master cylinder. It still did it. This is what got me to thinking it may be the ABS.

What would happen if you're stopped on a steep grade with a heavy trailer with no trailer brakes? :(

MP

[Inspector]

My 93 does it as well. It is a normal thing with hydroboost.
Denny