Just wondering, has anyone done a swap? I know the option has to be there but what donors are there for the swap? Any bolt ons or a 9" with factory discs that can be swapped. I'm hoping there are some JY donors available. Hopefully something that will fit in 15" rims.

 

I have no idea if it's out there or not but it seems like it would be a mod that would be 99% headache and 1% gain. First off, the front brakes do more of the stopping than rears. if they didn't you'd see a lot more vehicle fishtailing. Second, even if you found discs that could be swapped for the drums you'd probably have a brake proportion issue to deal with. The brake system is designed to use drums and the amount of force applied to each brake is based on the systems capacity. If you were to switch drums for discs you run the risk of throwing the stopping power balance out of whack and thus would have to modify the system to correct stopping proportions.

I don't know if any of the above is 100% accurate... I'm basing my opinion off what seems like common sense to me. I would stick with the drums.

 

If you can find a rear out of a Versailles or Granada, some had factory discs. Unfortunately, they were the small pattern, if you were looking for the large pattern.

Any of the kits that I've seen were also for the small pattern. If you get the caliper brackets, all the rest you can get at your local parts store. I helped a buddy with this set-up on his Mustang (converted to five lug with 9 inch).

1970s Lincoln Versailles/Ford Granada 9-inch Rearend Swap - Tech Articles - Mustang Monthly Magazine

or get a kit
9 Inch Ford Bolt-On Rear Disc Brake Kit - Speedway Motors, America's Oldest Speed Shop

I have a couple of guys telling me to do this on the '81 I'm building, but I can't see enough benefits to do the swap. I opted to just go to a 11" drum over the 10" seeing the front brakes are large enough.

 

here is a conversion kit Hope tis can give you an idea of what you would have to do

9" 1979-86 Disc Brake Conv. 3/8" Studs

 

Not clear if you're looking for a kit for a 9 in rear end or if you have the ford 8.8 rear end. There are kits available for both. It you've got an 8.8 rear end, Wilwood makes kits that fit our trucks (avail thru Summit Racing), and you can also get a kit from Bronco Graveyard. If its a 9 inch, you can get kits from many sources. You will need to replace your proportioning valve, and maybe your master cylinder - not a big deal in the grand scheme of things. I hope that helps.

Ron

 

Check out this thread for ideas...

https://www.ford-trucks.com/forums/8...sion-help.html

 

I know the poster said he has a 9" rear end, but I have a question. On an 8.8 rear, wouldn't it be possible to take the rear disc brake system (and proportioning valve) off of an Explorer with an 8.8 rear? Could that possibly be a bolt on application, with very few modifications? I wonder if anybody has tried that yet with any success. I'm just curious.

 

Oh, now that's an idea. Pull the axles and backing plate for the drums, and bolt on the caliper brackets and calipers from the (to narrow) Explorer rear end. I think that might work. Could you grab the proportioning valve from that donor at the same time? Oh my, I guess we've got a lot to ponder

 

I've often thought about usin' Explorer parts for a rear disc swap. If it uses the 5x5.5 pattern it should be very easy to just swap discs, caliper brackets, calipers, and proportioning valve over and have it work.

I think I'd try to find a master cylinder with more capacity tho, just in case.

 

The Explorer doesn't use the 5X5.5 pattern. But everything else "should" fit. Just need to find a suitable rotor with park brake. Want you could do is have the Explorer rotors re-drilled for the proper pattern.

 

Hmm... My dad has an 80 F100, now that would be a killer setup on that truck. Oh wait, its a 9"...damn...

 

Check fullsizebronco.com for write ups on everything brakes. They have great budget conversions and parts list to look for when in the bone yard.

Also, pirate4x4.com is a great resource too, just don't ask any questions and use the search feature.

Alot of guys are using the factory 4x4 rotors up front that are slightly machined to fit over the hub and 80's Caddy Eldarado calipers back.

Summit sent me the wrong cross drilled rotors (for a 4x4, I have a 2wd) when I did the F-350 master & booster/Tbird front caliper conversion. So my plan is to use the 4x4 cross drilled ones on the rear for the conversion.

So my final plan will look like this:

80's F-350 Master and BB--------------------------Done
F-350 Proportioning Valve--------------------------Done
New Stainless Steel Brake lines to ----------------Done
70's TBird or big body Ford caliper----------------Done
Drilled front rotors (2wd because that is what my truck is)

Rear is going to be the 4x4 rotors machined to fit over hub
Summit has the weld on axle tabs for the caliper mount
Undecided rear calipers with functional E-Brake, maybe explorer to keep it ford

These are just some ideas. Don't get discouraged and think it is to hard to do. Just do some research because you are not the first nor even the 1000th person to attempt this modification. Just remember when hot rodding to write down the several non stock parts on a list so you know what pads and rotors to re order at the parts counter!

 

I used a kit from Summit that was simply and worked great. Now that was on a 12 bolt but they basically have the same thing for the Ford 9" and 8.8". You will also likely have to redo the brake lines. Most drums are hard-lined right up to the backing plate/wheel cylinder. For discs, you have to put a flex line in as the caliper needs to float. Not only did this require different brake lines but had to weld tabs to the axle tubes to anchor the flex line fitting in
definetly look at the master cylinder and proportioning valve as well. The brake system needs to be balanced or you'll be locking up the rears. I also had to run a different parking brake cable as the disc and drums actuate differently

 

also keep in mind that to pull the old backing plates off and bolt the new caliper brackets in place requires pulling the axles...which now exposes you to possibly replacing seals, bearings, etc...the usual stuff you find when you open something up. While this is not a show stopper...it is also not a quick and dirty (well it can be dirty) afternoon bolt on job