I had a brake failure in my 78 f250 4x4 camper special. I fixed the problem, but the brake light in the dash is still on. How do I make it go out!? Wondering if this is the reason my brakes are not as powerful as they should be, or if I still have something to work out?

Todd

 

you need to reset the dual master cylinder spool to the center. it shifted to the side that lost brakes to shut them off so you don't lose the other side. best to read the repair manual to do it right. If you are going to own an old truck buy the Ford factory manuals, cd or paper. I payed $15 for the complete set for my '76. get the wiring diagrams too, your life will be soooo much easier

 

Agreed, they can often be found on ebay for pretty cheap, i paid $25 for my 5 volume set, worth every penny.

 

Ensure the master cylinder is full of brake fluid and the system is free of air.

After that,

Get in the truck and start the engine. Slowly push the brake pedal to the floor. It should go out. If it doesn't, you still have brake problems.

 

C8AZ2B264A .. Low Brake Fluid Warning Light Switch

Fits: 1968/79 F100/350 / 1969/79 Econoline / 1968/70 Passenger Cars

The switch threads into the brake differential proportioning valve.

What happens: The plastic switch develops cracks around the threads causing brake fluid to seep out.

When that occurs, the low brake fluid warning light on the dash comes on...and stays on.

 

hi does anyone have the part number for the brake proportional valve for a 1978 f250 thanks garymartin@vodafone.co.nz

 

D5TZ2B257B .. Brake Differential Proportioning Valve

 

I tried to use the procedure listed in one of my old Chiltons truck manuals. It did not work. I manually reset the spool on the bench. All is well now!