mustangexprt

hey all newbie here. I've got a brake problem with my 1999 f-150. I replace the rear calipers, master cylinder, and power booster. I've bleed the system till I'm blue in the face and the brake peddle still goes to the floor. Can anything in the abs system cause this? Thanks for any info.

torkum

Did you adjust the push rod on the booster?

Good old Bill

Hey newbie, welcome to the site. Am assuming you've been bleeding the fronts also till your blue in the face, I feel for you. My strange pedal feel is frustrating and I too am questioning the unknown ABS. Your case, is no pedal pressure, am I correct? Did you bench bleed the master cylinder before installation? If you havn't, doesn't it make sence to bleed 5" lines out of the master back into the reservoir than the whole system. In these chat rooms everyone gets insulted or peeved off. I don't know your experience so I'm trying to be as basic as possible. Torkum's point about the booster push rod length is a valid one. If half the available pedal travel is lost before contact is made with piston in the master, we have very poor brakes. All for now.

mustangexprt

thanks for the replies, yes i bench bled the master cylinder and adjusted the power booster rod. This thing sure has got me baffeled.

mustangexprt

forgot to say, the peddle has some pressure witrh the engine off but when i start the truck the peddle goes to the floor.

Good old Bill

What you are experiencing is the function of the booster. I'll explain. Normal brakes. Engine off, pump pedal, it keeps getting harder and higher as the vaccuum booster is depleted of vaccuum. OK, pedal high and hard, hold it there and start the engine, the pedal with the vaccuum assist goes down to the normal height. Thats is an old school way of testing the booster. Back to your problem. What started all the brake work? Why the replacement of master cylinder and booster? Need input.

mustangexprt

Thanks for all the input, I found the problem. I replaced the left rear caliper first (because it was sticking) then drove the truck, well then the right rear started to hang also. Sooo I went to my parts store and got the oppisite caliper. Not knowing that in the first place they gave me a right for a left. So what I did was put the left caliper on the right and visa versa. This made the bleeders on the bottom. And since I was getting frustrated I didn't notice. It's amazing what "sleeping on it" will do. Oh well at least it works now.

Good old Bill

My father had a saying that fits right now. "Too quick old and too late smart!" Am glad you are good to go, one last question, you actually drove this with no brakes? Had to be a six pack or more.