Brake Mod: 4runner/Maxima

[Gregs672000]

Greetings fellow Roadster nuts!
As requested I have taken a few pics of my Toyota 4runner/Maxima vented disc brake mod. I will try to explain it here. My camera sucks so hopefully the pics are ok. Keep in mind that I did not do this thinking "kit". It will require welding and grinding, and the rotors will need to be turned down a bit both in diameter and thickness... but I don't remember exactly how much, but I can guide you on where I got that info. Also, please keep in mind that I am NOT an engineer, and since this is a brake mod do this at your own risk! I can say however that I have not had a single problem with this system since day one. They work great, do not fade, seem pretty well balanced to the Roadster master cylinder and rear brakes, and I could not be happier!

Anyway, here is what you need:
1987 Toyota 4runner calipers (left and right). Other years may work (like '84-'88?) but I do recall that Toyota changed the caliper close to this time... maybe '89. Cost $65 each, loaded, no core on Rockauto.com
1988 Nissan Maxima rotors. Cost $11.02 each on Rockauto.com, beck/arnley #0802162 should work. Can probably find fancy drilled ones etc if you so desire.
You may need an adaptor for your flex lines. I have braided steel lines that had adaptors on them for the Roadster calipers and I THINK they bolted right into the Toyota... but I can't be sure and I don't plan to take it apart to see. I suggest you locate a Roadster flex line and test it in the Toyota, and if it works or requires adaptors let others know or update this post.
You may want a spare set of caliper mounting plates, since you will be modifying them permanently and if you screw up somehow or want to go back to stock (?) you can. I do have a set here and if someone wants to BORROW them they can, and then send me back two good ones.
You will need a properly sized drill bit and tap in order to drill and thread the new holes to mount your caliper, and probably access to a drill press or have a very steady hand. Match the tap pitch to what ever good quality bolts you select. I think a 2" length is about right (forgot to measure, sorry), proper size being best determined by what will fit through the caliper (again, I don’t remember what I used). Might need a couple thin washers for shimming if your grinding is off a bit.

Remember, the rotors need to be modifed slightly. While at the autoparts store, have them look up the max thickness of the Toyota 4runner rotor. Then, have the Maxima disc turned down to this thickness. Also, I had the outside diameter reduced as well, not sure how much but it is now 2.25 inches from the center hub mount to the outside edge. The Roadster hub will not fit down through the Maxima rotor. There is a lip in the center hole that will pretty much guide you in how much to remove, just grind until things fit flush.

I am going to assume you have already removed the Roadster braking system, and have removed the dust shield and caliper mount. You cannot use the dust shield, but it has never been an issue nor has the disc gotten grease etc on it.

Remove the Roadster hub from the rotor. I think the bolts will bolt directly to the Maxima rotor. Bolt it on to your modified maxima rotor.

Modify your caliper mounts: Grind the welded-on nuts off the back of the mount, then weld up the holes. Turn it over and weld on a ¼ thick plate of steel to the caliper mounting ears and shape accordingly by grinding, test fitting with the caliper, etc until you are happy that you have enough room to drill and tap your holes with enough material to make the hole strong. The Roadster caliper holes are 3 inches from center (or so, see pics) while the Toyota is about 3.5 inches. Mark them with the caliper, then drill and tap. I was lucky on my holes but if you are off slightly you can probably get away with modifying the caliper holes a little bit. Note: I think a 1/4 thick plate is about right. I had to shim it slightly between the mount and the caliper for the rotor to run in the center of the caliper. I think a total "height" of one inch would be perfect... see pic.

Reassemble the whole thing (no dust shield), and check to make sure the rotor runs in the middle of the caliper and is not hitting anywhere (rotor too tall and hitting the caliper or hardware, or scrapping on the body etc.). Grind or shim accordingly. Install your flex lines, bleed and you should be good!

BTW, I pushed on a stock wheel I have in the garage and it fit without the spacer no problem!

Happy to answer questions etc. Hope this helps someone out!

Below are the pics. I will do my best to describe them.

[sxtoz]

I wonder if you made a caliper mount to accomodate the 3.5" spacing and to clear the rotor without having to machine the outside diameter down if it would still clear a factory wheel...

[Gregs672000]

Seemed to me that there was some room but again I don't recall how much I took off, and I only designed it to be sure to fit my wheels. You could go to an autoparts store and have them pull out a Maxima rotor in the right year and measure the diameter or height from the center hub to the outside edge of the rotor... but really, getting the outside diameter cut down is no big deal, and the same shop that turns rotors will be able to do it in minutes.