Just replaced my brake booster on my 2005 Envoy XL 5.3l V8 4WD. The brake booster was making a hissing noise. I did drive with it hissing for about a month. It was my only vehicle and had to work and I just paid all my bills and rent, so I had to wait until my next free check. I maybe drove about 100 miles this was. While driving with the bad brake booster it did brake fine, but it was harder to brake and sometimes the brake pedal went all the way to floor on a hard/sudden brake. I also would feel the ABS kick in when braked hard.
Now that I replaced the brake booster it does stop but the pedal feels spongy or just soft. I only drove it 10 feet forward hit the brakes then reversed and hit the brakes. Did that a few times. The vehicle does brake within a few inches of stepping on the pedal. However, the brake pedal can still go all the way to the floor ever time I brake. When I brake it feels like the normal stiffness when braking, then it feels soft/spongy and continues to the floor. This happens when the engine is running. When the vehicle is not running the brake pedal gets stiff but can still be pushed another couple inches down.
Part of me (and wishful thinking) thinks I just got used to the brake being hard to brake and now that it's fixed, it just feels soft. But I'm sure I'm wrong there.
I was thinking of bleeding the brakes to see if that fixes it. My scan tool does have the ABS bleed function. However, I did not disconnect any lines from the master cylinder when I replaced the brake booster. I just moved the master cylinder out of the way. The master cylinder was tilted upwards where the part that bolts to the brake booster was skyward. Brake fluid in the master cylinder is full but there is a small amount of air on top by the cap.
Also all the rotors and pads are new. Replaced all four about 2 months ago.
Maybe any air that was in the master cylinder got into the lines when tilted?
Would driving that long with a bad brake booster make the master cylinder go bad?
Would any other brake system go bad as well such as the ABS module. No ABS or any other codes come up on the scan tool.
Now that I replaced the brake booster it does stop but the pedal feels spongy or just soft. I only drove it 10 feet forward hit the brakes then reversed and hit the brakes. Did that a few times. The vehicle does brake within a few inches of stepping on the pedal. However, the brake pedal can still go all the way to the floor ever time I brake. When I brake it feels like the normal stiffness when braking, then it feels soft/spongy and continues to the floor. This happens when the engine is running. When the vehicle is not running the brake pedal gets stiff but can still be pushed another couple inches down.
Part of me (and wishful thinking) thinks I just got used to the brake being hard to brake and now that it's fixed, it just feels soft. But I'm sure I'm wrong there.
I was thinking of bleeding the brakes to see if that fixes it. My scan tool does have the ABS bleed function. However, I did not disconnect any lines from the master cylinder when I replaced the brake booster. I just moved the master cylinder out of the way. The master cylinder was tilted upwards where the part that bolts to the brake booster was skyward. Brake fluid in the master cylinder is full but there is a small amount of air on top by the cap.
Also all the rotors and pads are new. Replaced all four about 2 months ago.
Maybe any air that was in the master cylinder got into the lines when tilted?
Would driving that long with a bad brake booster make the master cylinder go bad?
Would any other brake system go bad as well such as the ABS module. No ABS or any other codes come up on the scan tool.
