Hopefully somebody will be able to help me. I just need someone to point in the right direction. I replace my brake pads about six months ago and the rotors everything went fine. The brake pads that I put on were absolutely worn slap out after only being on the truck for six months. It is my daily driver. The rotors have a lifetime warranty, so I replace the rotors and the calipers because of the age of the truck. I bled the front calipers and I make sure that there was no air in either caliper. But I did not bleed The rear wheel cylinders because they're fine. When the trucks not running the pedal does get stiff but when you start the vehicle the pedal goes all the way to the floor and the ABS brake light comes on. I'm not seeing any codes with my code reader. I'm at a loss so any help would be greatly appreciated.

 

Sounds like air in the system, or its out of fluid.

 

I'm going to rebleed the entire brake system tomorrow, and I will update after I do that. it has plenty of fluid I made sure that the master cylinder never ran out of fluid when I bled the brakes. If that does not cure the problem what else should I look for master cylinder brake booster??

 

Could also be the master cylinder has failed.

 

If your pedal was good before you did the work, and isn't now, more than likely it's just a matter of bleeding everything out. Having someone help do it makes life a lot easier.....

You shouldn't be munching up brakes that quick either. Verify that your rears are working, and properly adjusted.

 

Yeah I had my 15-year-old was helping me. Sometimes their attention span is somewhat to be desired. I'm going to bleed the entire system completely starting in the rear moving away to the front. If for some reason I can't get the brakes to act right do you think it's possibly the brake booster or the master cylinder. I don't want to throw parts at it I want to find out what the root cause.

 

I sometimes have that problem after replacing brake components. Usually, it's just pump the system up a few times, and everything is good. (make sure you aren't leaking anywhere......) Try bleeding things out, and see what happens.

 

Definitely bleed the system again to make sure its not just air in the system.

Sometimes you can cause a failure in a the master cylinder by causing it to go the full cycle (down to the floor). If it hasn't moved that piston that far in a while, you can rupture the seal on junk accumulating in the cylinder (internal leak - no fluid loss). Perhaps its a light leak, and when you use the power booster, its easy to make it fail. Sometimes the MC will fail, and fill up the power booster... it'll look like its not leaking out of the system.

 

The master cylinder can leak into the booster, so other than low fluid, there is no visible leak.

 

So just an update on where I'm at with the brakes. I completely went back and
re-bleed all of the brakes. I did it twice and made sure that there was no air in the system whatsoever. When the truck is not running the pedal gets firm just like it should. When I crank the truck the pedal goes to the floor and I can pump the brakes and it's still spongy, but I don't feel comfortable at all driving it. The ABS brake light is on. But when I pump the brakes up the light goes off. My question is do you guys think it's the brake booster and master cylinder.