Homemade disc brake conversion

[eou_edu]

I search around this forum quite a bit looking to see if anybody has posted part number for a disc brake conversion. Looks like I can buy front kit for about $1300 from several different places and about $2000 for all 4 wheels. Has anybody done this and have a parts list for both front and rear? Sounds like the dana 30 and dana 44 have a the same kit so I'm assuming that won't change.

So far several hours of reading has only told me:
-rear calibers from an 83 cadillac eldorado
-rear disc from "a jeep". One thread said maybe a cj7 but you have to have the axle machined if you do do this.
-front disc and calibers maybe from a 76-77 bronco?
-brake lines and e brake cables come easy


What made me think this is a little on the expensive side was the one part number I could find for rear calibers from an 83 cadillac eldorado was $38 new (no core) on rock auto and about $140 buying them at the same places you buy the kit. I've also read that if you do the rear discs you can't use 15" wheels. It bothers me as well to buy something like this as part of a kit then 10 years down the road have NO idea where or how to get a part to replace them.

 

[broncobuddha]

I used 79-85 GM front calipers for the rear (no brake). And Jeep rotors. I didn't have to grind anything.

You will need weld on caliper brackets.

Sent from my Pixel 9 Pro Fold using Tapatalk

 

[Apogee]

There are numerous options to put disc brakes onto an EB, however I would first ask, do you really need rear disc brakes? The drum brakes are simple, cost effective and include an excellent parking brake, arguably better than what most disc brake kits can or will provide? The 1978-1985 Cadillac Eldorado rear parking brake calipers use a FMSI D154 spec pad and have a 5.47" pin spacing, so they are interchangeable with the GM "metric" D154 front calipers, however the caliper piston diameters are Ø2.03" for the parking brake calipers and Ø2.50" for the front calipers, so the rears would be much better choice with respect to front/rear brake bias and balance. Unfortunately, these parking brake calipers are somewhat notorious for being difficult to adjust and not the most reliable, especially when not set religiously. The ratchet mechanism used to adjust for pad wear can get corroded and seize, which then prevents the caliper from adjusting to account for pad wear, which then causes the pedal to get lower over time due to the larger and larger gap between the pads and rotors.

Up front, most of the vendors sell kits, noting that some are based on the GM D52 single-piston calipers and others use the Ford calipers. Either way, performance is similar and parts are readily available through both the EB parts houses and normal auto parts stores. FWIW, the 76-77 EB front disc brakes are essentially the same as the 76-79 Ford F150 front disc brakes in terms of calipers, pads, rotors and caliper mounting brackets.

Tobin

 

[phred]

The rear discs add a “cool” factor but in my opinion not needed on an EB. I’ve got them on both my EB and my full size 78 bronco and frankly the rear drums stop as well if not better than the disc and are much more user friendly

 

[papy]

I would invest in a hydro boost before disk brakes for the rear.
I went disk rear one of my 79's and can attest to what phred said. I found the drum better that the disks

I did the chevy disk front on my 67 dana 44 and kept the drums in the rear. also went with a junk yard HB set up. one of the best upgrades IMO

 

[ntsqd]

I put Expedition rear discs on the D60 that I put under the rear of my '96 FSB because I wasn't going to haul around those drums!
I went with Hydro-Boost at the same time. That is my second vehicle with H-B and I've just put H-B on the Wagon (#3) in my sig with no brake upgrades/changes (yet).

 

[Broncobowsher]

Front disk brakes using junkyard parts (and now re-pop parts) is in the tech section on this site. The short instructions, GM Dana 44 front brakes (correct spindle) and you replace everything spindle out with GM stuff. Except you use a Ford brake rotor. Then there are the high dollar Wilwood brake kit options, that can get you big rotors for that big brake kit. But you have to go with large wheels. I almost forgot at SEMA there was another Bronco disk brake kit that used off the shelf consumables (pads, calipers, rotors, etc) and a couple new hard parts to make it all work together. That looked like a nice way of running more modern brakes. Hopefully someone (Todd Z?) will chime in.

Rear disks. There are hundreds of ways of doing this. First off, as stated, why? Short wheelbase and tall center of gravity leave very little need for powerful rear brakes. Stock drums are a really good park brake if you want one. The stock rear axle has multiple different offset, and bearing combinations possible. And no real junkyard bolt together stuff. Jeep rotors are possible. I found Geo Tracker front rotors are a perfect fit over the wheel studs. One of the harder parts is keeping a small enough rear caliper as to not make the rear brakes too powerful. An adjustable prop valve is fine when a minor adjustment is needed, but horrible for a massively out of balance system.

 

[ntsqd]

The drum p-brake in the Explorer RDB's appears to be more than suitable for an EB. I can vouch for the same basic design, only slightly larger, as used in the Expedition RDB's being more than enough for an FSB.

Unless you're really lucky, neither bolts onto the usual 9" under an EB. They are close though.

Actual braking performance is not the only reason to be interested in rear discs. If you drive thru creeks & what-not you already likely know all about how badly drum brakes suffer when filled full of water-borne debris. Discs have a far smaller problem with this. With the emerging trend towards street performance and more emphasis being placed on ride quality than has even been made in the past, the reduction in unsprung weight of rear discs over drums is worth looking at.

 

[eou_edu]

There are numerous options to put disc brakes onto an EB, however I would first ask, do you really need rear disc brakes? The drum brakes are simple, cost effective and include an excellent parking brake, arguably better than what most disc brake kits can or will provide? The 1978-1985 Cadillac Eldorado rear parking brake calipers use a FMSI D154 spec pad and have a 5.47" pin spacing, so they are interchangeable with the GM "metric" D154 front calipers, however the caliper piston diameters are Ø2.03" for the parking brake calipers and Ø2.50" for the front calipers, so the rears would be much better choice with respect to front/rear brake bias and balance. Unfortunately, these parking brake calipers are somewhat notorious for being difficult to adjust and not the most reliable, especially when not set religiously. The ratchet mechanism used to adjust for pad wear can get corroded and seize, which then prevents the caliper from adjusting to account for pad wear, which then causes the pedal to get lower over time due to the larger and larger gap between the pads and rotors.

Up front, most of the vendors sell kits, noting that some are based on the GM D52 single-piston calipers and others use the Ford calipers. Either way, performance is similar and parts are readily available through both the EB parts houses and normal auto parts stores. FWIW, the 76-77 EB front disc brakes are essentially the same as the 76-79 Ford F150 front disc brakes in terms of calipers, pads, rotors and caliper mounting brackets.

Tobin

I probably should have started this thread with an explanation why I want to put disc on the rear. The ford 9" rear I have already has mounting brackets for the disc brakes on it but that is it. Not brakes disc or drums of any kind otherwise. So I either have to grind that off and buy all the disc brake components including back plates, or just go with disc brakes. I think in this situation disc brakes will actually be cheaper for me.

 

[Broncobowsher]

That actually makes things worse. Have no idea what the welded on brackets were set up for. The GM calipers are the most common, but far from certain. And the offset could be a hard one to match as well.

Get the brakes you want to use, try fitting them. If the brackets are correct, win. If wrong, cut and put on ones that match your mix of parts.

Front disk brakes are pretty standard. There are 2 common disk brake packages you find up there. Factory Ford or GM. With a handful of oddball stuff.
Rear disk brakes are the wild west. Anything goes. No 100% junkyard bolt ons that fit all Broncos. (I think there was that one Lincoln that would fit if you had the right year and GVW package).

 

[ntsqd]

There is a very rare and hard to find Mercury (& maybe Lincoln?) RDB that will bolt onto the Big Bearing 9" (Not "Torino") housing & axles. We put a set on a '60 El Camino that got a 9" and double UCA conversion about 35 years ago. NOT recommended. Parts are rare and hard to find, and the p-brake function was useless (cue GM "Caddy" RDB's).

Since the housing is bare I'd convert it to the Torino bearing housings and have Moser, Dutchman, et. al. make you a new set of axles to match. Then you can actually bolt-on the Explorer rear disc brakes which do have a decent p-brake function.

 

[eou_edu]

There is a very rare and hard to find Mercury (& maybe Lincoln?) RDB that will bolt onto the Big Bearing 9" (Not "Torino") housing & axles. We put a set on a '60 El Camino that got a 9" and double UCA conversion about 35 years ago. NOT recommended. Parts are rare and hard to find, and the p-brake function was useless (cue GM "Caddy" RDB's).

Since the housing is bare I'd convert it to the Torino bearing housings and have Moser, Dutchman, et. al. make you a new set of axles to match. Then you can actually bolt-on the Explorer rear disc brakes which do have a decent p-brake function.

Not sure where you gathered I have a bare housing. The 9" is complete besides brakes.

 

[ntsqd]

It's bare of brakes, right?

 

[thegreatjustino]

There is a very rare and hard to find Mercury (& maybe Lincoln?) RDB that will bolt onto the Big Bearing 9" (Not "Torino") housing & axles. We put a set on a '60 El Camino that got a 9" and double UCA conversion about 35 years ago. NOT recommended. Parts are rare and hard to find, and the p-brake function was useless (cue GM "Caddy" RDB's).

I've managed to find three of these Lincoln setups at the local junkyard over the years. As stated, the parking brake is the same as the Cadillac stuff. Because I was still running the stock EB shock mounts, I couldn't mount the calipers in the rear of the axle. Being on the front, there's no logical way of hooking up the parking brake cables - even if I could get long enough ones to loop around the axle. At some point, when I finally get this Bronco up and running again, I'm going to pull the Lincoln rear discs off and just go back to factory drums. They aren't worth the headache in my opinion.

 

[ntsqd]

I own an EB with Explorer RDB's on it and I can't imagine driving it with rear drums. Truck came to me on 37's and the first time I drove it any distance I had a panic stop on the fwy. Fronts are std. Ford rotors, but it does have H-B. To say that I was impressed with it's short stopping distance would be an understatement. Those brakes hauled those huge tires down from speed in remarkably short distance. The caveat about this is that particular EB has a 130 inch wheelbase, so it is not a great short wheelbase data point.

After dealing with drums that never seen to be in adjustment in spite of meticulous efforts to do that and keep them that way for decades, I've no interest in drums. They are great for p-brake functions and they are better at holding a static position than discs but in all other meaningful ways they suck. A bad choice in the particular set-up should only condemn that system, not rear discs as a whole.