I am going to convert the rear drum brakes on an 81 f100 2wd 9" to disc brakes. Has anybody done this yet and if so how were parts availability?Btw this truck has the small bolt patern and a 31 spline axel shaft.I was going to try a mustang kit and see if I could modify it .

 

I am in the process of doing this, but there are lots of kits to do this and if you shop around you should be able to do it for 400 bucks and it bolts one, or you can do what i'm doing.

The first thing you need to do is to locate a late 70's/early 80's licoln mark 5, or ford versalies. You will need the entirerear disc setup (its easier just to grab the entire rear end), then you will need the MC and prop. valve as well. Then you need a set of rotors off the front of a 81-96 4wd 1/2 ton, rebuild kit for the lincoln calipers (if they are rebuildable, as rebuilt ones are expensive), new pads, you will have to have new rubber lines made as well as fab up some e-brake cables as well. And you will also need an adjustable p-valve to get the rear brakes porpotioned right with the front, they cost about 40 bucks through summit (mine is a wilwood)

First thing you do is clean everything up so than all rust is gone and everything is nice and shiny (be sure to paint everything you can to prevent rust). After this is done you have to take the caliper bracket apart so that the caliper can be spaced out about 1/4" total (to clear the larger center radius of the truck caliper) using a couple washers, then reassemble. The next thing to do is to have to axle flanged turned down so that it fits inside of the rotor beening use (again about 1/4-3/8"), then the alxe bearing must be pulled (i would replace them with new ones, as well as the seals) so that the caliper brackets can be placed on the axles as they gobetween the bearing retainer and axle flange if i remember right, then reinstall the axle and bolt everything back up, the caliper mounting bracket bolts to the same 4 holes as the bearing retainer (the holes might need to be egged out with a die grinder to fit properly). Then install the rotors over the flange followed by the caliper (you can actually interchange this caliper with the front caliperon you truck, as the only difference between the 2 is the lincoln caliper has the ebrake stuff) and pads. Then replace your stock mc with the lincoln one, and the same goes for the p-valve as well, then install the adjustable p-vavle in the rear brake lines after the licoln p-valve.

Pictures of all the lincoln stuff is located here: https://www.ford-trucks.com/user_gal...&albumid=12938, i have yet to install everything as i have not had time to do so.

As for the bolt pattern, just find a set of 31 spline axles in another truck that has the 5.5 on 5 pattern.

 

the lincoln setup doesnt sound too bad but i was going to try to avoid having the e-brake in the caliper.I was looking at the explorer setup with the e-brake shoes on the inside of the rotor.But I'll have to explore all options first.Thank you for your responce.

 

That setup will run you more money, as the rotors are a special type and thus more expensive verses using the 4wd front rotor. OR you could go with a e-brake mounted on the tranny ouput shaft (if a steady bearing), or mount one on the pinion of the 9", then you can get rid of the the ebrake on the caliper and use the much cheap calipers that your front brakes use.

 

Hi, You don't need the front rotors you rear on the F100 is the small bolt pattern 5 on 4.5 not larger 5 on 5 so everything from the Lincoln Versallies looked like a granda would bolt right up same bolt pattern also if you get the master cyl and the proportioning valve then you will not need an adjustable as the valve from the lincoln is already set for front and rear discs. If you don't get the prop. valve then you might need the the adjustable valve not alw ays nescessary unless rear discs are locking up.The purpose of the proportioning valve is to provide different amount of pressure from front to rear. You can look for and Disc conversion made for a nine inch rear with the 4.5 bolt pattern as on mustangs and most older lincolns. Good luck .

 

I saw a kit from summit for the mustang that was a preety sweet setup and i think that I will be getting that one as I want to keep it with the 4.5 on 5 bolt pattern.Thank you all for your input.