Step By Step
First, you need to collect the rotors, caliper mounting brackets, and calipers. You can either hit a junkyard to get all this stuff, or you can save yourself the headache and do what we did. Drivetrain Direct can get you practically everything you will need, and its all new and clean.
Start out by stripping off all of your old drum brake stuff. Thats rightdown to the spindle. Now that you have the hub and drum off you should find someone who can press the old wheel studs out or you can bang them out with a hammer. Next, place the rotor behind the hub and have the wheel studs pressed through the rotor and into the hub. If you dont put the rotor behind the hub your brakes wont line up with the calipers.
Attach the spindle and Chevy Dana 44 caliper mounting brackets with a couple bolts to test for caliper figment. You will need to replace the twelve original fine-thread backing plate bolts with ones that are 1-inch long. You could also step up to some studs at this point.
In order to provide clearance for the caliper you will need to grind a little material off of the knuckle. With the caliper mounting bracket on the spindle you can get an idea of how much grinding will be necessary to fit the caliper. Remember that as the pads wear out, the caliper will move inward because of its floating design. If you dont grind enough, your caliper may hit the knuckle and render your brakes useless. We ground the fill plug for clearance, although you could just replace the plug with a flush-mount one. Now you can start grinding the knuckle between the two bolts that are furthest to the back of the knuckle. You dont have to remove a ton of material, but make sure you have good clearance by periodically replacing the caliper mounting bracket and caliper for test fitting.
Also grind the caliper a little to make sure that there will be no contact between it and the knuckle as the pads wear out, but be careful not to grind through the casting. Once you have removed enough material, you can then begin rebuilding your front axle. Now would be a good time to replace those worn-out bearings and seals. Remember to pack the bearings and grease everything.
We decided to move the hard brake lines from the axle to the frame. We used a couple pieces of bendable brake line from our local parts store, and a set of stainless steel brake lines from Explorer Pro Comp for a Chevy 1/2-ton. We used the metering block from the new Pro Comp rear brake line to split the front hard lines to both sides. Bleed the brakes and you are on your way. Make sure to check the caliper clearance as the pads wear.
Early Jeeps with closed-knuckle Dana 25 front axles are not known for speedy deceleration. In fact, stopping in a hurry with the 9-inch drums can cause a religious experienceor at least the utterance of a few sacred words used in vain. So what is to be done? You could find a narrow-track Dana 30 complete with disc brakes from a later CJ, but that can become quite expensive if the axle needs to be refurbished before installation. So why not put some discs on your Dana 25 using common easy-to-get parts? Heres how it works.
Explorer Pro Comp