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Rear Disc Conversion on an 2003 4x4?


Mirage775

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If all of the parts are cleaned VERY well and coated in anti-seize then the brakes should self adjust just fine on their own. Unless they're assembled wrong, which is very, very common.

I also hate drum brakes, but if they're put together right, they're pretty much drama free.

I converted my 8.8 to disc brakes and I wish I never would have. I've ran across a few other guys with the same problem too. Mine wear the inboard pad REALLY bad. I've put new calipers on, new caliper slide brackets, checked the rotors were centered/spaced properly in the caliper after bolting it all together.. Nothing helps. I'm a maintenance mechanic by trade, with 30 years experience, and I've never had anything continue to beat me like this disc brake conversion.

On my V8 swap truck I left the drum brakes alone other than a quick disassembly, cleaning, and coating with anti-seize. They're flawless.

GB :)
I rebuilt my drum brakes right after I bought the truck, as I was having a difficult time stopping. Wish I still had the pic of what it all looked like, when I pulled the drum! The shoes looked like they were original and weren't worn much at all, but all of the springs and both adjusters were either destroyed, frozen, disintegrated or missing completely! I put a good brand of replacement shoes on and a complete new spring/adjuster kit on both sides. I use the parking brake everytime I turn off the truck. I've been tinkering with vehicles for 25+ years and I'm very mechanically inclined.

Which disc brake conversion did you install? Explorer or Mustang? Are there more than those two swaps? I would hate to do the swap and run into the problems you're having though...

It's like everything else in the modifying world, just personal preference. I've read that when people put 33" tires on steel wheels, that the drums won't engage or engage, but don't stop the truck? That's the tire/wheel choice I'm planning to run, that's why I was interested in the conversion.
 
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adsm08

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The Explorer swap will drop you 4 to 5 inches, if you don't get spring perches welded to the top.

The 2011 axle presents a number of other issues, such as independent wheel speed sensors at the wheels and no provision in the diff for the center one.

The Explorer axle is the best bet, you just need to get perches and shock tabs put on it.
 
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don4331

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Oh, I wasn't sure what a DJM kit was? So, would that F-150 lowering kit work with the Rangers leaf springs, without a problem?
https://www.summitracing.com/int/parts/djm-fk3000-5 is what I am talking about. :) At the time, I didn't have a welder, and no one would touch welding on an axle for me. You are just using the kit "inverted" as to how DJM intended it to be used.

They work fine with Ranger leaf springs. Mine might (probably does) have an extra set of holes, but then my Ranger has a Superlift (and a few other more serious mods.)

My Ranger had no issue stopping with 32's except on ice, but that was tire issue, but then again they were on 17" Mustang Al rims.

Mustang rear discs were an unmitigated disaster under my daughter's Ranger. They were eating inner pads on an almost monthly basis until she stopped using the parking brake. And I wasn't thrilled about her not using brake given truck is a manual and Calgary is in foothills of Rockies. And we changed: rotors, calipers, cables, adjustments, etc, etc. in attempts to make it work.

Now, we were using V-6 Mustang parts*. Mustang Cobra rotors/calipers might be better (larger/vented), but cost was significantly higher, so we just installed the OEM axle from my SCab (with 10" Aerostar drums) under her RCSB, and called it a learning experience.

I have to agree, wet drums don't stop well. Not a big problem in Calgary. 4wd for me is about getting around in snow in winter/on dirt roads during spring break up.

I agree, customization is all about personal taste.

*My son got all the next to new pieces for his car when we threw in the towel.
 

Bird76Mojo

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Mustang rear discs were an unmitigated disaster under my daughter's Ranger. They were eating inner pads on an almost monthly basis until she stopped using the parking brake. And I wasn't thrilled about her not using brake given truck is a manual and Calgary is in foothills of Rockies. And we changed: rotors, calipers, cables, adjustments, etc, etc. in attempts to make it work. Now, we were using V-6 Mustang parts*. Mustang Cobra rotors/calipers might be better (larger/vented), but cost was significantly higher, so we just installed the OEM axle from my SCab (with 10" Aerostar drums) under her RCSB, and called it a learning experience. [/QUOTE] Same exact experience that I'm currently having on my 2001. The only thing I can guess on at this point is during normal daily driving, there isn't enough pressure to the rear brakes to make them self-center, using both pads equally. Under hard braking or emergency stops, it stops well. I've had it all apart a dozen times and watched while my father was applying the brakes. The calipers do indeed self-center while doing that, but I wonder about normal everyday driving where you're just lightly applying the brakes a 100 times a day, making it not completely self-center, and just wearing the inner pads. Makes me wonder about proportioning.. I also wonder if the calipers are releasing 100% because the rotors will be a little hot to the touch after a short drive, but they never seem to get overly hot. I've eliminated every other possibility, and I NEVER use my parking brake. I even left a tiny amount of slack in the parking brake system to be double sure it wasn't ever engaging. I've never been stumped by ANY mechanical problem like I am with this one. Properly set-up drum brakes work very well and are pretty much drama free. I wish I would've stayed with drums for sure! With my heavy-af 33x12.50-15" Falken mud terrains the drums still worked awesome. GB :)
 

don4331

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I also wonder if the calipers are releasing 100% because the rotors will be a little hot to the touch after a short drive, but they never seem to get overly hot.

GB :)
You are supposed to have a little residual pressure on disc brakes to ensure a firm feel:
https://www.speedwaymotors.com/Speedway-Disc-Brake-Residual-Valve-2-PSI-Purple,5312.html

So, it shouldn't be not releasing.

My thought was Mustang calipers/rotors aren't up to the weight of Ranger, specifically, tires on my Ranger alone weigh more than tire & rim on son's Mustang.

10" solid rotor, 38mm piston for Mustang versus 11-1/4" solid rotor, 48mm piston for Explorer...the '10-11 Ranger was 11-5/8" vented rotor, same caliper piston diameter as Explorer.
 
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adsm08

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You are supposed to have a little residual pressure on disc brakes to ensure a firm feel:
https://www.speedwaymotors.com/Speedway-Disc-Brake-Residual-Valve-2-PSI-Purple,5312.html

So, it shouldn't be not releasing.

My thought was Mustang calipers/rotors aren't up to the weight of Ranger, specifically, tires on my Ranger alone weigh more than tire & rim on son's Mustang.

10" solid rotor, 38mm piston for Mustang versus 11-1/4" solid rotor, 48mm piston for Explorer...the '10-11 Ranger was 11-5/8" vented rotor, same caliper as Explorer.
Hmm, I wonder how those Ranger rotors would work on an Explorer rear. I'd prefer vented.

Guess I may have to experiment next time I need brakes.
 

don4331

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Hmm, I wonder how those Ranger rotors would work on an Explorer rear. I'd prefer vented.

Guess I may have to experiment next time I need brakes.
Adms08:

You need both Ranger rotors and calipers - the calipers are just slightly wider, to fit the vented rotors. I should have been more precise in my original post, but they bolt right onto the caliper mounts.

The one I am curious about::

The caliper mount for '97-'04 F-150 rear discs from 8.8 rear axle is supposed to bolt onto the Explorer axle. Then you need F-150 calipers and rotors - you will need to change the 5 x 135mm pattern on the F-150 rotors to the 5 x 4.5" Ranger pattern; and you might want spacers for the hub to rotor as F-150 was larger. You will need 16" or larger rims, 'cause the 1/2 ton rotors are 13-1/8". It also requires either a proportioning valve, ABS or preferably both.

While the F-150 rear rotors aren't vented, you would have to be doing something crazy to need vented rotors that large.
 

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