I am slowly building a 79 F600 4x4, I am putting a 460 in it, lifting it and going to run16x20 michelin tires. I am tired of trying to fix the hydraulic brakes and want to convert to air brakes. I have access to a 900 series 5-ton military truck axles that have air brakes, what would I need to convert the rest of the truck. Any ideas on what to use for an air pump? This truck will have a pickup bed on it and be more of a toy but I want to be able to stop those big heavy tires, any help is appreciated.

 

go find a F700 , F800 with a 429 and air brakes and take all the stuff off of it !

 

far as i know that military 2.5 and 5 tons are air over hydraulic

 

The axles I will get are from the 900 series trucks, they are full air brakes, they use the wedge style brakes. I just picked up an 88 F700 with air brakes and stops on a dime, the 79 hardly stops at all.

 

on the 79 what all have you done to the brakes ?

 

I have replaced master cylinder, both boosters, bled it a dozen times, and still not sure if they will work right and stop my truck with the oversize tires.

 

dumb question , on the rear brakes did you get them adjusted and there are 2 wheel cylinders for each wheel in the back and if 1 is leaking or froze up the brakes wont work to well !
the tires you have should not be to much more to stop than a set of duallys 8.25x20 !

 

Converting to air brakes will be quite a task.

Mounting pump
mount primary & secondary tanks (wet tank if desired)
installing gauges
low air lamp
push pull dash valve for ebrake
dual circuit treadle valve
front brake qr valve
rear brake relay valve w qr.
rear brake qr for the e brake
All the hoses and brass in between.

The hoses and fittings alone will probably cost over 500. Add in the valves, and tanks and you'll easily be up over 1000.

A parts truck is highly recommended.. Damn brass kills on projects like this..