ok i have a few questions? brakes kinda bite

1 i didnt know about the porpoting valve under the truck andbleed it,could that have hurt the valve.
2 if i bleed the truck right will it make the brakes better if i bleed the right,if the valve isnt bad.
3 the brakes seem to have no pressure behind thme soime times sometimes they work ok i have to change the front brake lines they are very soft and brittle thats why i am asking
4 i have read the haynes book i have and will do it this time as it says.

thank you for your time and happy holidays

 

youve answered your own question with the part about doing it right this time , there should also be a part about re'centering the purportioning valve, good luck , bob

 

well they bite still i could not get the valve to move in or out. so i am now thinking the valve is broken or wore out inside. i had to bleed it so i could move it. had to get it out of moms parking space. has eny one bought a vavle from anybody like npd orautokraferts and had good luck with it or should i try to get one from ford if they still have them.

 

Your light must be on in the cab...correct? If you do a search, I think you will find that your in good company, as many people have the same problem. The valve can be quite hard to center and may require several tries. Don't be so quick to throw parts at it, as it may be how you do it and not what you do it to. Bleeding the brakes will not damage the valve, even if done incorrectly (unless the system was left dry or very dirty). Check and replace your vacuum hoses and (vacuum) caps first, as this is a cheap fix and allows you to rule out a top-side leak. Since the valve piston will move to and cut off an area of low pressure, you can create a "false" low pressure in the front and then build pressure in the back (the most common L/Pressure read) to correct the valve. If you bleed in too much air this can cause you more trouble than it's worth, and the light will still be on with poor braking. So get experienced help if your not sure and never drive anything without correct working brakes, for you and everyone else on the road! You might also think about checking all the brake cylinders for a leak, as that too can cause low pressure. Make sure the master cylinder fluid is 1/4 from the top and has never been dry. From everything you mentioned it sounds like a fluid leak or air in the system and not the valve itself. Good luck!