My brake pedal goes almost to the floor when I’m braking.
I replaced the rotors,pads,shoes,power booster and the master cylinder 3 times.
Had it bled twice and I still have a soft pedal, but now it firms up a bit as I pump the brakes.
Any ?'s
JohnnyM
You probably need to have somebody more competent bleed the brake hydraulic system.
When the brake pedal goes to the floor, and if the master cylinder has already been replaced, unless the replacement master cylinder is defective, then the problem surely has to be air trapped in the hydraulic system.
Whoever did this work for you did not do it right! Proper bleeding of the system should not result in a soft pedal.
If you did this work yourself, you probably missed a few steps.
Since you have all these new parts and if you have no leaks, please have a qualified mechanic go over the work and make the necessary corrections.
I’d agree with VDCdriver about the bleeding given that it firms up when you pump it. Was the master cylinder bench bled before it was installed? There is also a specific sequence for bleeding at the wheels. Was that followed?
The flexible brake lines at each wheel may also be due. The can get weak and some of the braking pressure goes to expanding the lines rather than actuating the brakes. I’d worry about proper bleeding first.
Does it have anti-lock brakes?
If the vehicle has ABS, you first do a standard brake bleeding procedure. Then you take a DRB scan tool to cycle the HCV pump and its solenoids to purge any air. Then you repeat the standard brake bleeding procedure.
Tester
Assuming you don’t have ABS. As mentioned above ABS requires special treatment. Have you confirmed that the brake fluid level is not going down over time, days, weeks? It’s important as a first test to confirm whether you’ve got a fluid leak or not when you have this situation. Just how did this all start? As mentioned above, soft brake hoses can cause this. The only way to rectify that is to replace the affected hoses. Why did you replace all those brake components in the first place? Because of this soft pedal problem, or something else? Does your truck require special brake fluid beyond the common Dot 3? Was the previous bleeding done with a pressure bleeder, or done by hand, with one person pressing on the brake pedal and the other opening and closing the bleeder valves? As mentioned above, it is important that the master cylinder be bench bled before installing it. And it is possible – not likely but possible – for even newly installed master cylinders to fail right out of the box.
This vehicle has at least rear ABS, which can be bled the normal way. If it has four wheel ABS, I believe a scan tool is necessary to complete the job as @Tester said.
Are the rear brakes properly adjusted?
I agree with @cigroller
If that brake master wasn’t bench bled, you’ll always have a shitty pedal
ABS is electrical. Even if ABS is not working you should still have brake pedal. Re bleed everything