i have a 98 ford f150 4x4 and i have replaced the master cylinder with a new one the front calipers, brake pads,and have bled the entire system and there is no leaks anywhere and my brakes are still spongy would the problem be the fluid control valve on the master cylinder, im running out of ideas thanks

 

Did you replace the rubber hoses to the calipers, they tend to collapse internally

 

no i didnt is this common with these trucks

 

Very common when the calipers are sticking but so is caliper pins. That's why I change both.

 

thanks for the info i will replace them

 

Did you do any work to the rears? When you do work on the front brakes, you're not going to notice it if you don't set up the rear shoes. Normally after you do front brakes the pedal is still going to be spongy if you don't set up the rears. Also the rear brakes on this generation truck have a tendancy to sieze up and cause a spongy pedal, I kow I have the same truck. Just my .02 cents. Hate to see you spending all this money if it could be a simple fix like this.

 

It is a good idea to adjust the rear brakes... You may have leaking rear wheel cylinders or worn out shoes, these conditions will cause long pedal travel.

Even if you have plenty of meat on you shoes it may be far adjusted...

Also, the RABS proportional valve may be at fault... If you only have rear ABS that is.

Every lil bit of info helps, hope I did!
Eric

 

I had a similar problem. Upon further inspection, I found that my rear cylinders were leaking and the shoes were worn out. I spent an afternoon and $450 rebuilding the rear brakes, turning drums/rotors, replacing shocks, and installing new pads up front. Trouble is, I still feel like the pedal does not have a "solid" feel to it for the first several inches.

Is it just my imagination running wild or does this point to an underlying problem?