Dumb Brake Question

[Yeller]

I will never understand the desire to use eldorado calipers. They are the worst design I’ve ever had the opportunity to work with. The set up procedure is difficult, the reliability is horrible and the piston size is way too big, providing way too much brake power in the rear. For simple tuning and a strong parking brake it is hard to beat the explorer set up. I have not investigated retro fitting them to a D44 or model 20. Nor have I looked into the TJ, XJ, JK, JL options either

[sierrablue]

Well I know the XJ has drums in the back, and the ZJ has non-vented rotors in the back with OK calipers and a crappy parking brake design. Oh, and once you get A LOT of miles on them, the brake pads actually wear into the bracket, and you have to weld it back up so they don't stick.

The others seem like ok options...

[Stuka]

Uhhhhhh other than the lug pattern, there is nothing different between my rear axle and the one in a '74, and mine's been swapped to 6x5.5, at least from what I can find. It's even a flanged setup rather than a tapered one. This is the first I've seen reference to them being different at all, and I researched the snot out of it when I went into the parts store and they couldn't find a bearing set for a '71, but they had them for a '74. I know the fronts are drums vs. the disc Delco front brakes, but mine's been swapped to the '74 front axle anyway, even if that was relevant to the rear axle. BJ's seems to indicate that the '74-'76 uses a different drum and shoe setup than the '77+, but all I can find that changed was they switched to a bigger spindle in the front, and did the spring changes in the back. Where are you getting this info about the rear axle being different?

Also, once the discs are on there, I should just have to replace the pads and occasionally the rotors, with occasional bleeding. Obv stuff happens and I may need to replace the caliper or lines or whatever, but they're 100% self-adjusting by design, don't drag at all when they're properly adjusted (vs. the slight drag of the drums), and are way less of a PITA to work on. Additionally, it's not that much more expensive than rebuilding the entire brake system as was suggested. Rotors for that kit are cheaper than the drums. There's a little more upfront cost but not a ton, so I don't really see the downside... Now, if I was getting the BJ's kit, yeah that'd be incredibly expensive. Piecing together my own it's looking like under $500.

71-73 had flanged D44's with a 5x5.5 pattern. The change over to flanged axles was mid way through '70. Before that they had tapered shaft axles.

You are correct that the drum between an M23 and a 74-79/86.5-91 D44 should cross over. But the 71-73 is a different braking setup (as mentioned above), plus being 5 lug.

There are a few setups you can use for a parking brake. There are drive shaft mounted brakes, some people use line locks (Not reliable over an extended period as they will bleed down, and won't pass safety inspection if your state has that). Late model axles with disc brakes have a drum in the center for the parking brake. Would be cool if somebody made a kit to retro fit that setup to an older axle.

Again, disc brakes have some great advantages. If price doesn't matter, and you find a parking brake solution, go for it.

[Yeller]

OP's rear axle is converted to 6 lug

[sierrablue]

Thanks @Stuka and @Yeller.

I'm personally not a fan of the driveshaft parking brake, and I don't like the little drum on the rotor; that's what the ZJ has, and we've discovered that with an automatic (does anybody use their parking brake hardly at all with an auto? Other than my granddad, who insists that his WK2 will roll down our driveway if he doesn't...), in the salt and stuff, they are extremely prone to rusting and then causing lots of problems when you DO go to use them. I like the cable that clamps down the pads on the rotors; I think it's a good setup.

Just out of curiosity, why do all of the FSJ parts places say the drum is the same '74-'91, and others
say the AMC 20 used different drums? I measured mine; they came out to 11x2" just like the ones on the D44, and when I was helping somebody shop for brake parts on the AMC 20, everything I saw indicated that they used the same backing plate and everything...So what's different?

[Stuka]

(does anybody use their parking brake hardly at all with an auto? Other than my granddad, who insists that his WK2 will roll down our driveway if he doesn't...)

I have a pet peeve against anybody I see thrown their vehicle in park without the parking brake, and watch the vehicle bounce off the parking pawl. I have seen that tiny piece of metal break, and seen it pop out and let the vehicle roll away. Though, I live in the mountains, and I have owned almost entirely manual transmission vehicles. So parking brake is pretty important around here, and to me. If you live in a flat area, I am sure its less of an issue.

Just out of curiosity, why do all of the FSJ parts places say the drum is the same '74-'91, and others
say the AMC 20 used different drums? I measured mine; they came out to 11x2" just like the ones on the D44, and when I was helping somebody shop for brake parts on the AMC 20, everything I saw indicated that they used the same backing plate and everything...So what's different?

Looking them both up now, the only noticeable difference is that the 70's one is finned, and the M23 one is not. Measurements are all the same. And my parts books listed them as being different. That however does not mean they aren't cross compatible.

[tgreese]

The aftermarket sellers do not have the hands-on knowledge that you or I might have. Typically the suppliers of the parts tell the sellers which years and models they apply to, and the sellers relay that info in their listings.

If the maker looks at the parts book and their part has a change of number that they have not built to accommodate, I expect they would not offer it.

Dunno about others, but Driver's Ed where I grew up had us put the transmission in park and set the mechanical parking brake. Habit now. I always set the brake regardless of the transmission type. Second the opinion about that dinky parking pawl.

Massachusetts has annual safety inspection. You must have a working parking brake.

[sierrablue]

Most of MN is pretty flat, and I just don't worry about it most of the time. Also since it doesn't really stop
it, only slows it with the drum brakes, I don't see it as particularly helpful unless I'm pointed downhill anyway.

Yeah, in Driver's Ed they always have you set the parking brake when you're parallel parking. But that's it; technically you could be legally in trouble for not having a working parking brake, but there's nothing saying you have to use it, nor are there inspections.

My dad's Mustang is the only stick I've driven much; we use the parking brake a fair bit, but we mostly rely on the transmission/engine to hold it in place. Most of the logic there is that if I were to drive something old (like my grandma's Mustang or my grandpa's old Merc), the parking brake isn't gonna do much even if it does work properly.

I'm not saying it's wrong to be cautious or anything. I just really don't use my parking brake. I want to have it for legal reasons, as well as the ability to use it if/when I need to.

[sierrablue]

OK, got the brakes working better; turns out my right rear adjuster was seized, and not only that, but it was seized ALL THE WAY in. Pulled it out, clamped it in the vice, hit it with some PB Blaster, and then took some channel-lock pliers and cranked on it until it came loose (took me forever to figure out that it has backwards threads ), but I pulled it all the way apart, smothered it in neverseize, and put it back in, then adjusted it. Brakes are rock hard like they should be again.

However, they're still kind of a pain and tend to have stuff like this happen a lot, at least for what I've been around for with my family's XJ, the truck, and now my SJ. If nothing else, sure they have similar
power to the discs, but with discs you can make a hard stop, and then get back up to speed and make the same hard stop again, pretty much all day long, and you won't have a problem, whereas the drums just can't shed heat that fast. We just had the ZJ out in CO, where I'll be spending quite a bit of time, and on the way down the one super steep slope, all 4 wheels were smoking. I can only imagine that rear drums would have faded out LONG before that.

So I've been continuing to research the rear discs. I found this kit that would allow me to use Mustang rear calipers, BUT I'd have to figure out drilling the rotors and such.

https://www.mpbrakes.com/rear-brake-con ... FB0E8DE946

I also discovered that the '90s and '00s Isuzu Rodeos have a 6x5.5 rotor, that's not super thick like the GM ones are. Additionally, they went on a Dana 44 rear end. They have a parking brake/caliper setup that's very similar to the TJ and Explorer style rear disc brakes. I haven't been able to find the actual axle-to caliper brackets for sale anywhere is the issue, and additionally I can't verify one way or another whether or not they use the same flange on the outside axle. I suspect it's pretty close, possibly the same as the TJ, and there's always that outside chance that it DOES just bolt up. But they came with 15" and 16" wheels so it should clear, so if I can find it, that's absolutely the way I want to go. If anybody has any info or anything on the Rodeo brakes, please chime in.

[sierrablue]

https://www.isuzupartscenter.com/oem-pa ... NC1nYXM%3D

This is the diagram of the setup, and this particular backing plate is out of stock, BUT I did find the part #. Same # on the Honda Passport too.