So I replaced not to long ago one of the front rotors the other one looks fine, front pads and the rear drum brakes looks fine, replaced the master cylinder and bled the **** out of the lines and the pedal is still the same:

You have to press a damn good amount of pressure to stop it which I got used to but when the truck sits for a while and then you drive it the feeling of the pedal stops just like it should only for like a couple of times of usage and then goes back to how it was. It's almost like there's rust on the brakes which seems like the adjustment is wrong and then once that wears of the pedal goes back down to being soft. I also have ABS but I've never seen that work at all. My brake booster box does have some rust on it but I don't think it's leaking because the idle is normal.

Any ideas you guys have would be nice because I'm running out of ideas.

Also I can slam my foot down as hard as I can and it takes awhile for that to "register" and I can barely get the tires to stop completely on a dry day.

 

I don't know much about adjustment in the front brakes, it sounds like a hydraulic problem. The only other parts to the hydraulic system are the lines and calipers. If the rear brakes are out of adjustment you can jack the back of the truck up so the rear wheels are off the ground and adjust the rear brakes until you can just hear the shoes rubbing against the drum and see if that helps at all. The adjustment access hole has a rectangular shaped rubber plug that you take out and then take a flat head screwdriver and turn the adjustment gear, which you should see when you take the plug out... it has angled teeth on it. It should only turn one way.

 

It sounds like your master cylinder may be bypassing inside. You won't lose any brake fluid so its hard to detect...other than the symptoms you describe.

 

That's what I was thinking my old one was doing, had the same issues and replaced it with a rebuilt one (I know I know those last about 10,000 miles but it was cheep and I was looking for a temp cheep fix) but I'm still having the same problems. Do you guys think it can be the air booster? It is rusty but the pedal doesn't harden while the engine is running unlike when its off and you keep pressing the pedal you lose the pressure. I don't hear a vacuum leak, I suppose I can try spraying throttle cleaner around it to hear for any changes..

 

Still think its the master cylinder bypassing...

 

Stupid question, but have you checked your rear brakes? The adjustment may be way out (or the cyls may be siezed). I had this happen with similar results to what you're having - I went through three "defective" master cyls figuring this one out.

 

I would tend to go with the seized wheel cylinders in the back. I had a similar problem but I was fortunate enough to have one of the cylinders blow out while I was bleeding the system.

 

I'm thinking it is either the adjustments or the cyclinders, because I can press on the brakes in the snow and whip out the back end much easier than any other rear wheel drive car or truck, they just seem weak so I'm going to adjust them first then replace ****

 

I was able to adjust one side really well and it did make a difference in the pedal feeling and stopping power but on the passenger side the dust cover was missing and I couldn't really tell if I was adjusting it or stripping the gears on the adjuster. It was to cold out to do it so in the summer I replace all that but for now thanks guys I can deal with this for now.