Bigger disc brakes for MM/D50

[Natureboy]

It seems like a few MM/D50 owners are interested in finding an easy solution for bigger front disc brakes, and from what I gather no one has found one yet. I found one.
I spent a good part of the day at the J/Y looking for options for bigger front brakes for my 87 D50 4x4. I found a great fit with parts from a Montero Sport. It comes stock with dual piston calipers, and 12-1/4" ventilated rotors. I had a 4x4 D50 and Montero Sport right next to each other, making it very easy to compare/test fit parts. The good news is it works very well with only 2 issues, both solved in an hour with minimal use of a grinder. The other solution is to switch to 16" wheels, which is expensive and requires larger tires, too.
The hub and spindle are the same dimensions as my MM, even down to the bearings. I don't know if the Sport shares a lot of other components with the trucks, would be interesting to find out, but these parts work.

These are the parts I took from the Montero Sport-
1. hub/rotor
2. caliper
3. caliper bracket
4. rubber brake line from caliper to union with metal line
5. dust shield and bolts

I'm doing this swap with my original, stock master cylinder, but if it doesn't work well I'll swap in the Sport master cylinder also. I think dual piston calipers have a greater volume of brake fluid, so it may be necessary to swap master cylinders, as I'll find out.

The first issue is the dust shield, and there are 2 solutions-the four bolts that hold it to the knuckle are indexed, or rotated, about 3/4" compared to the Sport, and it interferes with the lower caliper bracket, so it either needs to be cut with tin snips or the four holes redrilled to line it up correctly. Easy fix. The second issue is more time consuming-with the stock 15" wheels the caliper body makes contact with the inside of the wheel, preventing it from seating flush with the hub. You can either switch to 16" wheels, or do some grinding, as I did. I have pictures to illustrate, but it is a minimal amount of grinding, and it all fits great now.

Anytime you alter or modify brake components it should be done with care and common sense-mucking about with brakes can cause injury or death. So, with that in mind, let me hasten to state that the grinding involved is minimal, and no where near the piston bores or other sensitive areas. I took off less than 1/8" on the outer corners of the bracket and caliper itself, and am confident nothing has been compromised or made unsafe-the calipers bodies are pretty stout, as you can see in the accompanying photos.

So, with that said, this looks like a practical, affordable solution to weak stock brakes, made worse by installing larger tires.

Here are the photos-rotors.jpgbrackets.jpgmontero rotor.jpgbracket grind.jpgclearance.jpg

[Natureboy]

Oops, forgot to include photos of the calipers-tomorrow, plus test drive report, if I don't die.

[87octane]

Anybody know if 1st gen spindles dimensions match 2nd gen spindle dimensions? If so, this could also bolt on to a 1st gen 4x.

Natureboy, what year what year was the Sport? early 90's???

[Natureboy]

The montero sport was a 2000, 4x4 with the 3.0. I believe the spindles are identical between 1g and 2g 4x4 pickups.

[pennyman1]

All the parts on 1st and 2nd gen should be interchangeable - check for the parts for a 1st and 2nd gen at rock auto - if they are the same, then they interchange. Did that with a 91 accord and 92 prelude for fuel pump and other parts.

[Natureboy]

Looks like the wheel bearings are identical, so it should work. Just did a test drive-what a difference! Stopping power is impressive. Think I'm going to do the master cylinder just to keep it all the same system.

[pennyman1]

there is an article in street roder mag that does an excellent job of explaining the relationship of master cylinders to calipers and wheel cylinders and how a larger master cylinder bore gives more volume, but at less pressure, changing the feel of the brakes, and how to pick the right combination for your vehicle. It is a must read for anyone modding brakes - when I find the link I will post it.

[pennyman1]

Found a different article that is even better as it is geared for 4x4 vehicles - it is highly detailed: http://www.pirate4x4.com/tech/billavista/Brakes/

[Natureboy]

Awesome! Thanks. I love technical info.

[Rahtid]

Thats setup i have been running for 5 years,the rotors wont work on a 2wd because of the offset on the 4wd rotors.
http://www.mightyram50.net/vbulletin...=2388#post2388

[Natureboy]

did you have to do many mods to make it fit? After five years any problems with it?

[Rahtid]

no mods to fit just order a loaded caliper for a 92 montero, the loaded caliper comes with brake pads and new mounting bracket for the bigger calipers, no issue with this setup.

[recian]

And those calipers work with stock 2wd mm rotors?

That was to rahtid. His pics seem to be using mm rotors. Do the 4wd rotors from the monteros bolt up to the 2wd mm hubs?

[4doorciv]

I changed my rotors already. Need update to this thread so I can get bigger rotors. Please. Lol. 1989 MM 2wd.

[87octane]

4doorciv, No interchange from 2wd to 4wd. You're outta luck for brakes.

[87octane]

BTW, scored a set off a 2001 Montero Sport that came with factory 16's and those brakes are awesome looking and bolt right on the 4x spindles.

[4doorciv]

Anyone find any canyon or Colorado in the pick and pull they can use as a comparison?

[4doorciv]

Can I bolt on a 4x4 spindle? Lol.

[camoit]

I did find these rotors in the junk yard today. I didn't have a tape measure so I put my foot on one of them for sizing. I think only one is needed to stop the truck.
Does anybody know if this conversion was finished?

!cid__07-19-13_1019.jpg

[tomcat2587]

Do the auto hubs work on those monty set up? Any ideas on rear brakes? i have the 1 ton rear axle and the drums are 9x2"