QUICK DISCLAIMER!!! THIS MOD MAY REQUIRE MODIFICATION OF BRAKE CALIPERS AND MOUNTING BRAKETS. I DO NOT RECOMMEND ANYBODY CUT OR GRIND ON BRAKE CALIPERS AND MOUNTING BRACKETS. MODIFYING YOURE VEHICLES BRAKING SYSTEM IS ALREADY RISKY BUSINESS AS IT IS. COMPLETE THIS MOD AT YOUR OWN RISK!!!

UPDATE: After further research, I've found that 2021ish chevy traverse brake calipers may be a better option. They use the same parking brake motor but the the caliper is over all a little smaller and has a 44mm piston diameter. They should fit a 15" wheel better and and have overall better breaking balance before adding the adjustable proportioning valve. I may order a set and try them out. I will report back if I ever do.

So, I did a disc brake conversion on my 94 4runner a few years back (link to that write up here). While it was a very easy, inexpensive and excellent setup, I've never been real happy with the parking brake performance as do most people doing most disk conversion. I decided to finally come up with a solution. I've always been real impressed by the electric parking brakes on modern vehicles and decided I wanted to go that route as I find some basic wiring is far simpler than building good parking brake cables. So, I did some shopping around and found that 2020> Silverado 1500 rear brake calipers could be made to fit. Might be other options. Haven't found anything I like more yet. Found a set "used" on Ebay with 23 miles. For $160 shipped, its a price that's tough to beat. I ordered them up and started doing some fitting. They were a super tight fit on 15" wheels. if you have spacers, large offsets wheels or 16" or 17" wheels, this will be much easier for you.

Here is a quick size comparison between them and the Mustang Cobra calipers I was originally using.



Clearly, they are substantially larger and the Mustang calipers were already a tight fit on 15" wheels. Here you can see I already cut the lower portion of the bracket off before I realized I should take a photo.
I tried both 4th gen 4runner rear rotors and 3rd gen front rotors. There are pros and cons to each. I would recommend 3rd gen fronts however I settled on the 4th gen rears. I did this because the 3rd gen fronts will move the caliper slightly outboard requiring me to grind it down more for wheel clearance and I obviously wanted to keep that to a minimum. I will be doing this same mod to my Tundra in the near future and will be using the 3rd gen fronts on it as I have 17" wheels. The problem with 4th gen rears is the caliper bracket and outer brake pad doesn't clear the rotor hat and must be cut and ground to fit. Also the rear brake pad should be ground down a little as it also doesn't quite cover the entire rotor friction surface. 3rd gen fronts, fit the calipers and brackets very well, however will need a washer or two to shim the caliper outboard a bit to keep it centered over the rotor. It will also require you to turn down the axle flange diameter to fit inside the rotor hat. There may be better rotor options out there but these are the options I found available that didn't need modification to the fit the vehicle. Just for reference, here are some dimensions of between the two rotors.

3rd gen front: Diameter-318.5mm Thickness-22mm Height-70.5mm Bore-106.1mm Lug-6x5.5"
4th gen rear: Diameter-312mm Thickness-18mm Hight-68.1mm Bore-106.1mm Lug-6x5.5"
Bonus!
2020> Silverado Rear: Diameter-345mm Thickness-20mm Height-52.7mm Bore-? Really Small? Lug 6x5.5"

Something to note, third gens were also available with 297mm rotors. You don't want those. Buy the ones with the 16" wheel option. Also if you search for a different rotor for your swap, 22mm is the absolute maximum for the the rotor thickness. Anything larger I guarantee will not fit the caliper without sanding down the pads. You can't go much bigger anyways as you will begin to interfere with the bracket also. Stick with 18-22mm.

This shows the fitment between the two different rotors.

4th gen rears


3rd gen fronts


3rd gen front without washers


3rd gen fronts with two washers


Axle flange turned down a little to fit the 3rd gen rotors


Just like last time, I mocked up fitment on a spare axle shaft and drew up a template in Google Sketchup. I had to a LOT of grinding to make the caliper fit the 15" wheel. I located the caliper forward on the axle for clearance. Rearward, it would touch the shock absorbers. Top would touch the coil spring and possibly the frame rail at max compression. Bottom would be vulnerable to rocks. Forward just up a little to get ground clearance but still low enough to not interfere with the coil spring.

More Photos:

Side by side after cutting and grinding




Checking Clearance






Bracket cut out


Caliper bolted up.







For the brake hose I just continued to use the 1984 Nissan 200sx rear brake hose. Part number 8704310. I did have to trim the banjo end a little as it was a little too wide to fit the caliper. There are probably better options. That's what I used as I that's what I already had and was able to make it fit. If you use a different hose, get one with a 10mm banjo fitting on one end, a m10x1.0 IF fitting on the other and 11" over all length.

For wiring, I decided to use two DPDT switches so I can choose to lock them individually and do front digs. I used three conductor 14awg cable all the way to the back. These motors can pull as much as 30amps each at full stall. 14awg sounds way to small for a 60 amp load but it only draws that much for only a second or two and that's the factory Silverado wire size. The connectors I took from a scrap Silverado axle from work but I think I found the correct replacement part number 88988963. I found them for about $16 shipped. I ordered a set for when I do my Tundra. If these end up being wrong, I'll update this thread. If they are correct, I wont change anything.

Here is a simple diagram I drew up on how I wired them. You can use four wires which would be better. I used three because I still had three available in the seven conductor cable I used for the rear Toyota e-locker. Note: the DPDT switches actually must have a neutral position. The ones in the diagram are in a N/C position only because that was the closest image available in the software I used to make it. I used switches pre-configured to control a dc motor. Bought them on Ebay here for $13 each.


Switches in the dash. Not happy with how the left one sits. Gotta do some fine tuning to the hole I cut.


The switches I bought





Now, for braking bias, these calipers aren't ideal. The Mustang calipers have a 38mm piston with ~1133mm^2 of surface area and I think, was perfectly biased on a second gen 4runner. The Silverado calipers have 51mm pistons with ~2041mm^2 of surface area. That means they apply almost twice the force per PSI compared to the Mustang calipers. Because of this, they lock up. They lock up real hard. An adjustable proportioning valve is absolutely required. I used on from Wilwood part number 260-10922. I bought it for about $40. It is adjustable with up to 57% reduction. At the lowest setting, it is almost perfect but not quite, I suggest shopping around and finding one that can go just a little bit less. Plumbing it in was kinda dumb. I couldn't find a prop valve that had m10x1.0 IF fittings. Everything is either NPT (should never be used on brakes), 3/8-24 IF or m10x1.0 BF. I settled with 3/8-24 IF. Had to cut and flare the rear brake line with a standard fitting on it then make a new line with a metric on one end and standard on the other. The good news is 10mm and 3/8 fittings both use 3/16 lines. Its not the end of the world to have to do that, but it is annoying. Especially with how common m10x1.0 IF fittings are on most modern vehicles.

Note: NEVER install two prop valves in the same braking circuit. The stock LSPV must be bypassed to install an adjustable prop valve. I already bypassed mine with the last disk setup. I doubt the stock LSPV is tuned well enough for these calipers. You can try it but you're likely going to have to go adjustable. To bypass it, there are lots of how-tos available on Yotatech and many other forums. A quick Google search will get you what you need.

Now because the pistons are a little larger, the brake pedal does feel a touch softer. Its still plenty sensitive and works great. Most will probably be very happy with the pedal feel. I personally prefer REALLY firm pedals. I was using a 1" bore master cylinder from a FJ80 part number BMT090. With the stock 45mm piston front calipers and the 51mm rear calipers, the hydraulic ratio was about a 18:1. I switched to to a 1ton T100 master cylinder, part number BMT139 with a 1 1/16 bore. It doesn't seem like much but it brings the hydraulic ratio down to about 16:1. The pedal feel is much firmer and I am very happy with it. Bought it from Rockauto for $105.

New master and prop valve plumbed in


Any who, I think that's pretty much it. Overall I am very happy with the overall performance. I can set the brake on any hill and am completely limited only by traction. Plus I can lock up only one brake, put her 4wd front locker on and have about a 7ft turning radius. Its far more involved and expensive than using Mustang brakes but it is better I think. If you want cheap and simple and don't care about the parking brake too too much, use Mustang brakes. If you want the best parking brake setup you can get, use these. Feel free to ask questions. If there is something I forgot to touch up on, let me know and I will do my best to update the thread.

 

This is an interesting option for sure! I like the independent control you built it! I went from the standard chevy calipers to El Dorado ones.

https://www.yotatech.com/forums/f88/...ersion-314296/