Rear Disc Brake conversion - Maxima Caliper for the mooch

[noelawinslow]

So, Sean73 wrote up a basic... writeup of how he did the rear disc brake conversion with Maxima brackets and calipers from the late 80s rear brakes (85-88), and it was still fairly vague as to how exactly it was done, and I intend to provide a supplement as I study and work through this project conversion. So far, the list of parts is as follows:

 

85-88 Nissan Maxima bracket - you will be modifying this. There's a good chance you could just bolt it up and use 1/4" wheel spacers after boring the center hole but the extra weight is like two or three pounds higher, and nobody wants that, especially unsprung, so if you have access to a mill then you can get this done, or find a buddy with a mill and pay him to do it. The machining is so simple someone without any sort of training can do it and has.

 

85-88 Nissan Maxima Calipers - Buy these remanufactured if you want to be certain they won't give out. If you're getting these from a junkyard, you can't be sure they'll work properly. Rockauto sent me Tokico calipers brand new for pretty cheap, around $150

 

84 300zx 4 lug 11.4" front rotors - You have two options for getting these to work properly. One is to lathe them down about .3", the other is to cut the caliper's mounting ears open a bit more to allow the rotor to fit. I did a combo of the two so the lathe work in the future for new rotors will be a bit less intensive. You CAN do the work on a brake lathe if you can mess with it yourself. I did.

 

Optional 280zx master cylinder - You will have increased pedal throw without it, and may not get the same pressure to the brakes. It might be possible without, but I'd recommend you do it, it's a good idea.

 

Tools:

Mill

Dremel

Sawzall

Patience

Punching bag

 

Start by taking your bracket to the machine shop, be it yours or someone else's. I bored the hole to 83mm because it's a common enough tool to find, but if you can get it to 82 it should fit. Then, cut the outermost hole opposite of the two caliper mounting holes off. You will have to do this with only three holes in order to allow yourself to mount the bracket over the axle. BEFORE you surface the bracket, go to the axle and cut the back plate for the drums off. There, it's permanent. You have to finish the job now.

 

Go back to the mill. Surface the back of the bracket where the axle flange meets the surface of the bracket. Take it down about 5.5mm at first, then flip the bracket over, and cut about 5.5mm off the surface of the mounting ears where the caliper bolts on. That gives you a rough estimate before going back over it. Layers of rust, or other things, can build up enough to offset a specific measurement, and I can't be held accountable for you jumping the gun and whittling it down without being careful. This is a starting point, it's up to you to find what fits your car. Bolt it up and stick the rotor on.

 

You will find the rotor extends a bit too far out to mount the caliper. You will be mad if you are not expecting this. Punch the punching bag 19 times. You have the choice of fixing the rotors or fixing the caliper. Your options are extensive here. So go crazy. I wound up using a brake lathe to take down the outside diameter about .1" at first (it's not built for this purpose, but it's still a lathe, and every shop has one, it shouldn't be too hard to convince someone to let you do it, it just takes a bit of thought to get it to work properly) but I took measurements and found I needed another .2"ish off before it will fit. 

 

Alternative route - take a Dremel with a grinding stone and grind off the inside ridge of the caliper. You will find it doesn't give you all the clearance. Punch the punching bag 38 times. Feel better? Good. I don't feel comfortable saying it's a good idea to grind out the caliper, but your mileage may vary. My setup has quite a bit of clearance required that Sean73 didn't seem to have an issue with, so trim accordingly. 

 

E-brake is a different story. I haven't wired it up but I will and will explain the process.

 

Pics coming when I get my camera back. 

 

After all is said and done, I'm still in search of figuring out how to perfect the bias with the stock valves, I'll figure that out and edit accordingly. My goal is to get this all balanced for the street, then go to track use, but honestly, you DON'T need to do this. My reasons are primarily cosmetic. I want my car to look retro and modern simultaneously. 

 

 

 

[winstonusmc]

I run the rear 280zx rotors with mine with no modifications. 88 bracket and calipers with only 5mm off each side.

[RebekahsZ]

My Desert Z disc conversion requires the bigger rotors (I guess that is the 1984 300zx front 4-lug rotor. Did you say just to have them turned down in the traditional way (on the friction surfaced), or do you make the rotors a smaller diameter? Do you know what the FINAL measurement needs to be after machine work?