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Rear Disc Conversion Pics


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Here's what I did:

 

85-88 FWD Maxima Rear Caliper Flat Bracket- modified for S30 hub.

85-88 Maxima Calipers (similar to 240SX calipers)

84 300ZX 11.4" Brembo 4-lug rotors.

 

RearDisc_LH_web.JPG

bracket_LH_web.JPGbracket_caliper_LH_web.JPG

 

Ok. A lot of you are probably wondering what I had to do to the flat bracket to make it work. Well, it wasn't trivial, and I would not have done it if I didn't have free access to a machine shop. So, here it goes:

 

1) Bore center hole to 82 mm.

2) Cut 4th mounting hole off, so bracket is removable without removing axle stub.

3) Mill down the hub mounting surface to 7.5-7.75mm

4) Mill down the caliper mounting surface to 7.5-7.75mm

Edit:5) I also had to open up the holes on the mounting ears of the bracket slightly, since the rotor was rubbing the inner caliper a bit.

 

The stock flat bracket is 12 mm thick solid forged steel. That leaves a lot of room for machining. I looked online for aftermarket non-Zcar caliper brackets, and most of them are 1/4" thick (6.35mm). Mine are 7.5mm thick at the mounting surfaces, and 12 mm thick in the rest of the bracket.

 

I used the Maxima caliper because it has less of an offset on the hanger, thus it needs less offset on the bracket. Consequently, the angles are much less severe than if I were to use a 240SX caliper. In order for this mod to work with the 240SX caliper, the ears of the bracket would need to be cut and re-welded , because there is not enough material to merely mill down the bracket for the correct offset.

 

I used SS lines purchased from MSA, that are the same ones they sell for the 4x4 front brakes. At first glance getting the e-brake to work should be easy.

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Well, it wasn't trivial, and I would not have done it if I didn't have free access to a machine shop.

 

Why should this be a sticky?

 

I mean great job, excellent install. I wish I could do as well. But I sure don't fall into this catagory and I am sure 98% of the guys on this site don't either.

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Why should this be a sticky?

 

I mean great job' date=' excellent install. I wish I could do as well. But I sure don't fall into this catagory and I am sure 98% of the guys on this site don't either.[/quote']The machining involved is VERY SIMPLE, just some milling on a beefy common bracket. Don't know if there is enough here for "sticky status", but it is a very simple implementation.

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  • 3 months later...
  • 1 year later...

I have all of the 85- Maxima rear brake hardware on hand... I also have someone willing to perform the machine work in trade...

 

What I need to know is... in what way did you reduce the thickness of the brackets... Was this just for weight savings or to use the original harware??

Did you take them down to 7.5mm from BOTH SIDES?.. or OPPOSITE sides... I assume you need mirror images...

 

Thanks man...

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Well... I guess I will get out the scrap steel and just make my own brackets.. I don't like the fact that the Maxima brackets are WAYYYY TOOO thick anyway... I look at that 1/2" hunk of metal and i just cringe at the weight overkill... It will make a nice pattern for the hub bolts and that is about it... I think I will find some 3/16" steel and go from there...

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I have all of the 85- Maxima rear brake hardware on hand... I also have someone willing to perform the machine work in trade...

 

What I need to know is... in what way did you reduce the thickness of the brackets... Was this just for weight savings or to use the original harware??

Did you take them down to 7.5mm from BOTH SIDES?.. or OPPOSITE sides... I assume you need mirror images...

 

Thanks man...

 

I have pics of this install if you are interested.

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Absolutely...!!!!

 

I have already done some measuring.. I will need to take 0.200" off opposite sides to get the proder offset...

The Author said to take the thickness of the brackets down to 7.5mm.. but I have figured it out.. You need mill them down to 6.8mm thickness on opposite sides of each bracket...

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Absolutely...!!!!

 

I have already done some measuring.. I will need to take 0.200" off opposite sides to get the proder offset...

The Author said to take the thickness of the brackets down to 7.5mm.. but I have figured it out.. You need mill them down to 6.8mm thickness on opposite sides of each bracket...

 

Here are the pics.

bracket_caliper_LH_web (450 x 600)_thumb.jpg

bracket_LH_web (600 x 450)_thumb.jpg

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  • 4 weeks later...

ok.. the results are in.

 

This conversion works!... but it was a real headache... There are literally dozens of modifications that must be made for these parts to work effectively. Another note is that the small piston 240SX calipers will provide proper brake bias when combined with the vented 300ZX front disks and the largest of the 4 piston Toyota calipers. I feel that the larger piston Maxima calipers may have too much rear bias. I used the 240SX calipers.

 

1986 Maxima flat brackets

unmodifiedbracketflat.jpg

 

 

opening up the inner hole

holeyholesaws.jpg

 

I can't find my pics of the completed milled brackets

 

 

Here is a pic of the un-milled rear brackets mounted on the spindle. You must remove 0.195" of material from opposite sides of the bracket to allow room for the hangar between the bracket and the disk.

unmodifedbracket.jpg

 

 

Here is the caliper mounted with additional spacers mounted between the hangar and the caliper pin-ears. These spacers are neccessary when using the 240SX caliper with the 1986 Maxima Hangars.

Reardiskedge.jpg

 

 

 

I use Hawk blue pads on the front and Hawk black compound on the rears. This worked very well at Road Atlanta this past weekend. front to rear bias is PERFECT!

Here are some pics showing the blueing of the rotors. This shows that they are doing their fair share of the work.

Reardiskpackge.jpg

 

Reardiskwear.jpg

 

 

 

 

I would never do this unless you own a machine shop. Ross's conversion does all of this with minimal hassle. The Modern Motorsports kit is well thought out and WELL WORTH THE MONEY!!! KUDOS to Ross for really thinking this through. His kit is the best combination of parts with perfect rear bias when combined with the vented 300ZX front rotors and Toyota calipers.

 

 

....

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I installed Ross' brackets. I may have to pull the PS bracket back off for some minor machine work. Apparently, either the rear housing is poorly machined, Ross' bracket is slightly out of kilter or the outer pad is not seating flush. The outer pad is wearing at a severe angle (haven't looked at the inner pad yet). Enough to not allow the outer pad to contact 33% of the the rotor closest to the inner circumference. I imagine the outer area of the rotor is not contacted on the inner side either. I'll have to break it down and look. This is NOT to discredit Ross or MM as I very pleased with parts I've bought from him. I've never heard bad commentary regarding him or his products. In fact, I hope to purchase rear control arms as soon as I can convince myself to spend another $$$ for the 240Z.

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If you have swapped the outer pads for the inner pads you will have this condition of uneven pad wear. You say that the right outer pad is wearing funny. There are 3 pins on the inner pads with only one pin on the outer pads. The extra pins interfere when placed on the outside. You got both outside pads installed on the left side caliper, you have both inside pads installed on the right side caliper. The only single pad that would cause a problem is the outer right pad in your case. In other words, having too many pins on the outside will interfere, but having too few pins on the INSIDE will not.

 

There are 2 slightly different pads for each caliper. The outer and inner pads have different numbers of alignmet pins.

 

In fact, the pins are there to:

1. Peen on the little retention tabs,

2. peen on the wear indicators,

3. they locate the anti squeal shims,

4. keep the piston from rotating when the parking brake is set.

 

 

 

IF the inside pad will not seat correctly then...

The Piston might not be clocked correctly to ensure that the pins on the back of the pads are seated in the slots(in the piston).

You need to goto your parts store and purchase the universal piston turning tool.(and pull the handbrake and press the pedal together while relasing only the handbrake several times to adjust the handbrake initially)

 

 

I ran into the same problem on the race track, The car pulled slightly to one side. I checked everything out and found the piston had rotated slightly before it seated onto the pad. It was pressing on a pin on the back of the pad instead of the entire back surface of the pad. It was easy to diagnose and fix.

 

 

 

PS:

If you ever read the owners manual for the Nissan 240SX you will find that the procedure for SETTING the parking brake involves pressing the pedal firmly and then pulling the handbrake. That ensures that forces on the handbrake cables are low and it is neccessary to ensure that the HELICAL PIN inside the caliper will self adjust evenly and reliably, without turning the piston(even without the locator pins on the pads).

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