Ever since I got this on the road, the front brakes have been on my mind. They’ve been really good, just not spectacular. And knowing that the day would come when I’d have to address the small issues by doing a complete replacement of all the axle’s brake components without truly knowing what the existing parts came from originally… I was low-key dreading it.
There were two main issues. Under hard braking, the rear would break free just a hair sooner than the front. The way my system is designed, a proportioning valve isn’t really feasible, so I was going to first try a more aggressive pad. The other issue was that it had developed a pull to the right. I’d assumed this was due to oil on the pads, but I found that to not be the case.
All I knew about these brakes was that they were 4-piston calipers with solid rotors. All the research I did said that it should have single-piston calipers. One of the new guys at work is a Toyota truck guru, and he gave me a starting point. He said the rotors were most likely from an ‘85, and the calipers were from a later IFS truck.
I hopped on Rockauto and ordered what I thought it needed.
Nothing was right.
Starting with the rotors, the studs had to be pressed out to separate the hub.
The new ones had tiny lug holes that needed to be drilled out to accept the old studs, and the hubs had two bolts that (redundantly) lock the rotor to the hub - those needed drilled too.
Now the calipers… the old ones had a design I’ve never seen before. The pistons in the caliper were asymmetrical. One set of pistons were 1 1/2” OD, and the other was 1 1/8” OD.
You’d think that would make the pads wear unevenly? Guess what…
Since my setup uses banjo fittings instead of the standard flared fittings, I had to use my high-tech sanding disc to machine a flat, square surface at the fitting for the copper washers to seal. (Left = before, right = after.)
I bolted the new caliper in place and thought it was strange that I had to trim the dust shield to get it to fit. I got everything assembled and had an “Oh

” moment.
Note the huge gap between the rotor and outboard pad. These calipers are for a much thicker (vented) rotor. I ground the pad material off the old plates and tried using them as shims, and that is when I realized the size difference in these calipers. they’re not only thicker, but longer too, with bigger pads, so my shims wouldn’t work. I had to make new ones out of plate steel.
It was then that I realized my wheel won’t fit with that caliper. I had to make a 1/4” spacer to move the whole caliper inboard.
This made my brake hose and banjo fitting interfere with the steering arm, so that needed to be clearanced.
16 hours of headaches, frustrations and setbacks, I finally got one side assembled.
I did the math, and all in all, the caliper pistons have 21% bigger pistons, and the pads have 11% more surface area.
With all of the tricky parts figured out, and custom parts already made, the other side only took two hours.
Here’s one of those cool, “ why didn’t I think of this earlier?” ideas…
This Toyota axle uses transmission-style snap rings inside the hub. They are a major headache to use snap ring pliers from the side. I filed these grooves in them to make it a piece of cake.
So how do the brakes work?
Incredibly well.
All four tires lock up equally on dry pavement with a slight bias to the front, which is getting stronger the more I drive it. Should be perfect on gravel. Plus, there’s no hint of the jeep pulling to one side or the other; the wheel doesn’t budge when you let go and slam on the brakes.
Big headache, but a major win!
And now I have all of the part numbers for future reference.