amc model 20 rear disc brake conversion on a budget
i used 87 300zx rear calipers ($100)
96 geo tracker 4 door front rotors ($30)
and home made mounting bracket (free)
i should have gotten pre 86 z300 rear caliper so i could have used sami front rotors because they are the same thickness of the factory rotors...after 85 300zx rotors went from 10mm thick to 22mm thick... so i used 4 door geo rotors cuz they were 18mm thick... so my pads are starting out a half life but the rear should where down to quick but ill keep an eye on them... also these calipers have built in parking brakes so they will pass state inspection here in pa
I have seen this conversion, maybe over on Pirate and plan to do it on my CJ as a future project. Thanks for posting up pictures. Do you have any more photos of the bracket? What master cylinder are you using?
1978 Cherokee, 360/T400/QT...5.3/4L60E/NP241C in the works...
I want to do this also, and am ready to start buying parts, but its the bracket thats keeping me from starting. The other threads I've seen on this talk about fabricating a bracket up, but I wouldn't know where to start on that.
I also had already picked up an S-10 master cylinder/ booster for better braking, but I don't know if thats going to work with the 4 disc setup.
im just going to run my stock power brake master cylinder cuz i have the cj "big brakes"... they brackets where not fun to make... alot of metal work on them... i used 1/4in plate steel for the brackets.. The bracket is shaped like an '"H""... good luck
What do you mean by "big brakes"? Mine is an '85, and I think the rear drums are 11"; is that what you mean, that you have the 11" diameter, not the 10" drums? I had read a few threads about changing the mc and booster out with an S-10 setup for better stopping power, but I haven't switched over yet.
As far as the brackets, my problem is with cutting them. Really the only tool I have that would do a decent job is a heavy-duty jigsaw, but I don't know if that would cut through 1/4" steel.
Did you do anything to your proportioning valve?
Its hard to tell from the pics, but it looks like you are in the middle of a build, and wouldn't have tried the brakes out yet. If you have, how big is the difference, and would you do it again?
im selling my 33in trxus and getting 35in km2... my jeep has the 11in drums and 1 1/8in thick front rotors... im not working to worry about the prop. valve yet... im just going to try it out in the snow and see which wheel locks up first..is the front lock up before the rear im in good shape... the brackets i made i cut with a torch cuz my plasma cutter is broken still... what you gotta do is get the rotors and take a piece of card board and make a template of the bracket... a lot of guys only use 3 wholes to hold the bracket on but i managed to make a brackets using all 4 on the axle flange... i still gotta get a new brake line on my passenger side fixed... the reason why i did the swap was my wheel cylinder ripped off my backing plate and all my brake hardware on passenger side was destroyed... so i figured i might as well upgrade it while i have it all apart... the reason i have 2 in wheel spacers is that i have narrow track axles so i want more stability which i really need due to my jeep being a cj5...
Not to get off the topic you started, but I picked up the S-10 mc/ booster after reading about the upgrade here. I was at a local junkyard and they had one for $25 so I grabbed it. With front discs and rear drums, both with new hardware and pads/ shoes, I still can't lock the brakes up. I think it stops ok, but I don't have the braking there that I think I should so I decided to try the upgrade. I was thinking the same thing though when I got the mc home; it looks pretty much the same as the one I have on there now...
i really don't know...must cj master cylinder upgrades i seen are for cjs with manuals brakes... before i could lock up all 4 tires with 33in trxus m/ts on the street... i really don't think there will be huge performance gain running them instead of the stock power brakes "vacuum assist"... my friend did a disc brake conversion on his cj7 with scout 44s using bronco front rotors and calipers but the only master cylinder upgrade he did was a yj because he had manual brakes and it was cheaper then getting a cj power brakes setup and he is running 35in km2
thanks trapshooter...right now i have my axles built up to the point where i cannot do anything else to them... i have 4.10s Detroit locker in the back with alloy usa shafts and alloy usa diff cover and for the front is Aussie locker with nitro gear chromoly shafts, 0.250 dom tie rod and drag link with 3/4in heim joints, red neck ram hydro assist and rock it diff glider
amc 304 with t18a with twin stick dana 20 with tera low