M35a2 F350 rear brake upgrade

[Nates72Kaiser]

A couple of years ago I upgraded my M35a2 to disc brakes. I've got F550 calipers and F700 rotors up front, and F350 dually calipers and rotors on the rear axles. So far it has been amazing. I really love how much better it stops now. I can also just look to see how the brakes are doing without disassembling the hub, or even taking the wheels off. I was wondering if anyone who has done this has used a newer F350 caliper with electronic parking brakes. I like the idea of flipping a switch, hearing the parking brake come on, and knowing that it's not going to roll away.

 

[John S-B]

Any pics?

 

[Nates72Kaiser]

Here’s a few pics.

 

[Nates72Kaiser]

While you’re taking things apart, it’s a great opportunity to change out seals, bearings, and boots. Don’t get off the boat unless you are going to go all the way.

 

[Nates72Kaiser]

Front caliper and rotor

 

[El1T3 x M4R1NE]

Front caliper and rotor

I've got the Willwood front disc brake conversion from Boyce, but Id like to do the F550 and F700 rotors up front! How did you do it? Was it a kit or did you just make your own brackets and buy the parts yourself? Also, have you though about doing the F550/F700 parts in the rear?

 

[Nates72Kaiser]

I've got the Willwood front disc brake conversion from Boyce, but Id like to do the F550 and F700 rotors up front! How did you do it? Was it a kit or did you just make your own brackets and buy the parts yourself? Also, have you though about doing the F550/F700 parts in the rear?

Found a thread on pirate 4x4 where some guys were trying to find disc brakes for Rockwell 2.5 ton axles. That was a big help. I’ll have to dig around for the part numbers but yeah Ford F550 calipers and B700/F700 rotors. You will need new studs since the thickness of the rotor takes up too much space on the old studs. I bought mine from some truck spring place in Michigan. I did have to machine both the front hubs and front rotors. Open the rotor up just a hair and turn down the hub about as much. Nice machine shop in Xenia, Ohio did mine. That was about $900, but they are beautiful. I guess that’s the biggest reason why people only do the front with the F550/B700 combo. Once the rotor and hub were back on the truck, I fabbed up the brackets based on what I could find from pics of Hanks Deuce and pirate 4x4 threads. Make sure you are dry fitting everything as you go, and keep in mind the clearance for your rims. I want to keep mine looking stock but have better brakes and whatnot.

 

[Nates72Kaiser]

So last night I had an idea. Pinion brakes with Bronco electric parking brake calipers!

I got the idea while looking at my 2025 Bronco last night. I swiped a pic of Boyce’s pinion brake setup for reference.

 

[Nates72Kaiser]

Electric parking brake actuators are like $30 on amazon. I want to put a pinion brake up front and one on the back. That ought to hold her.

 

[El1T3 x M4R1NE]

I agree a pinion brake would make the perfect parking break.

As for your disc brake set up, Id love to use/copy your setup or similar. Ultimately, I'd like to have a whole F700/F550 set up on all 3 axles. I could go the Boyce/F350 disc brake route, but I just would feel safer knowing I can tell people I've got beefy breaks. Also, what are the specs of those studs you got from Michigan? and what was the name of the truck spring place in Michigan? Any info is greatly appreciated! Thank you!

 

[Nates72Kaiser]

I agree a pinion brake would make the perfect parking break.

As for your disc brake set up, Id love to use/copy your setup or similar. Ultimately, I'd like to have a whole F700/F550 set up on all 3 axles. I could go the Boyce/F350 disc brake route, but I just would feel safer knowing I can tell people I've got beefy breaks. Also, what are the specs of those studs you got from Michigan? and what was the name of the truck spring place in Michigan? Any info is greatly appreciated! Thank you!

Truckspring.com is the place. The

I agree a pinion brake would make the perfect parking break.

As for your disc brake set up, Id love to use/copy your setup or similar. Ultimately, I'd like to have a whole F700/F550 set up on all 3 axles. I could go the Boyce/F350 disc brake route, but I just would feel safer knowing I can tell people I've got beefy breaks. Also, what are the specs of those studs you got from Michigan? and what was the name of the truck spring place in Michigan? Any info is greatly appreciated! Thank you!

The place I got my lugs is called truck spring.com

Take a look at www.hanksdeuce.com His rig is awesome and he’s got some really good pics of his process throughout everything he’s done. I think he’s on here too. I almost bought the CAD file from the guy at black rock. I decided to just look at Hanks pics and eyeballed it from there.

 

[Nates72Kaiser]

Also someone once posted a list of M35a2 compatible parts that one can buy at Napa. I’ll try to find it again.

 

[Nates72Kaiser]

www.xm381.com has an M35a2 parts interchange list. That's where I got my info on the lugs, then I ordered longer ones for the front hubs from www.truckspring.com. While you have the front end torn apart, go the extra mile and replace your boots, seals, bearings and grease. I watched the Tactical Repair video on youtube for the tear down and rebuild of the front axle. Lots of great information there. I made things easier for myself and bought longer screws for the ring clamps. You're going to snip off the excess anyway, why not use a longer bolt and not fight it. I bought the thicker rubber boots from Red Barn Customs. They are nice!

 

[El1T3 x M4R1NE]

www.xm381.com has an M35a2 parts interchange list. That's where I got my info on the lugs, then I ordered longer ones for the front hubs from www.truckspring.com. While you have the front end torn apart, go the extra mile and replace your boots, seals, bearings and grease. I watched the Tactical Repair video on youtube for the tear down and rebuild of the front axle. Lots of great information there. I made things easier for myself and bought longer screws for the ring clamps. You're going to snip off the excess anyway, why not use a longer bolt and not fight it. I bought the thicker rubber boots from Red Barn Customs. They are nice!

Thank you! Lots of good information here! And I wish Red Barn was still around they had A LOT of good stuff… but yea I’ll see about eventually making some brackets like Black Rock made for Hank. I asked them if they still have the CAD files and they said no. As for most others, everyone acts like custom brackets for the deuce are the best kept secret.