Upgrading 720 brakes

[Crytek89]

Hey Guys,

 

I've been looking at doing some disc brake upgrades for my truck prior to the swap and wondering if anyone has found places (physical or online) that does upgraded brakes.

Thus far I've found a couple sites but the reviews seem a little bogus and I can't seem to find any that match the 2.4L RWD.

 

Any thoughts on doing drilled/slotted or both - street use only.

 

Is there a difference between the brake rotors from 4WD and RWD?

[wayno]

Just go with the late 1986 720/early hardbody brakes, that way you have the spindles you need, and if they are not good enough for you, you can upgrade to the 1990 V6 2wd hardbody dual piston calipers.

You could also buy Bell Tech drop spindles for the late 720/hardbody and buy all the brake parts new from the auto parts store, single or dual piston calipers with the late 86 720/early hardbody rotors and bolt them to your hubs you have now.

I believe you need the late 720/early hardbody spindles, I don't think the 83 thru early 86 720 spindles you have now will work, they are different.

[Lockleaf]

This is on a stock 86 720. I haven't checked to see if it works on my 85.

 

I just finished a "big" brake upgrade on my 86 720. I used the front brake setup from a 97 Pathfinder. The rotor is 11.2 inches in diameter as opposed to the stock 720 10.75 inches. It's also about 50% thicker. The pads are larger and the caliper is dual piston and quite a bit bigger.

 

These two comparo pics aren't very impressive, they don't really show how significant the difference really is. But here they are anyway.

 

Stock 720

 

Pathfinder

 

These comparo pics show the differences better.

 

 

Pathfinder on the left

 

 

Pathfinder on the left

 

This swap is also larger than the d21 v6 upgrade I have heard of people doing, but never seen.

 

Parts needed:

From a 96-99 pathfinder

Brake caliper

Brake caliper bracket

Brake rotor (00-02 might be an even better option)

* Brake backing plate (or you can cut/bend your 720 backing plate

 

Everything else you can reuse from your 720. The hub, rotor to hub bolts, caliper mounting bolts, bracket mounting bolts, brake hose, and brake hose banjo bolt - all stock 720.

 

Additional parts

Heavy duty washers, a 2-3 mm thick (x4), 12mm or 1/2 inch hole, I suggest grade 8 or 10.9, suspension grade stuff.

 

The only modifications that need to be made are to the pathfinder caliper, and this can be done before ever starting the install.

 

 

This is the back of the pathfinder caliper. The brake hose area needs to be widened to accommodate the 720s brake hose head, which is large and oddly shaped. I ground away some metal from the top and bottom on the inside of the caliper bolt area. I also ground the notch a little wider so that the brake hose would fit in it.

 

Doing this will allow the brake hose to be mounted in the best position possible on the back of the caliper.

 

The caliper brackets bolt right to the knuckle, but the offset is different from the pathfinder, so the caliper doesn't sit quite right.

 

First off, when mounting the bracket you need to space it out so it won't bind on the rotor. That's where the heavy duty washers come in. Place a washer between the knuckle and the caliper on each bolt as you put it together.

 

 

You can see the washers between the caliper bracket and knuckle here. This was during test fitting when I was figuring out what would work. I removed these and replaced them with washers about 1.5 inches in diameter and higher grade.

 

The other problem caused by the knuckle differences is that the pads overhang the rotor by about 1/4 off an inch.

 

 

I'm not overly concerned by this, but actually I think it's great news. In 2000, when pathfinders switched to VQ motors, they also increased the brake rotor size again, from 11.2 up to 11.8 inches. This bigger than 1/2 inch difference in diameter translates to a little over 1/4 of an inch per side of the rotor. I haven't tested this theory, but this would result in a perfect fit using 97 caliper/bracket and the largest rotor of this design that Nissan produced. Somebody try this and report back!

 

Here's a pic showing the diameter difference. The rotors are lined up at the top, so the difference is visible completely at the bottom. 00+ R50 pathfinder would be a full inch larger than stock. When I need new rotors I'm doing that.

 

 

The best news about this? The calipers clear a 15 inch rim, so even the largest rotor fits under my rims with no issues. I'm pretty sure 15 is the smallest rim it will clear though.

 

You should also swap out your brake master cylinder to a larger one. This upgrade allowed me to lock up 31x10.5s, which was not at all possible before swapping out.

[wayno]

It will work fine as long as you transfer everything from upper ball joint to lower ball joint over to your 1985, I believe the spindles are different, the late 86 stuff will not fit on a 85 spindle, I believe they are different, I suppose there is a chance that the spindles are the same, and if a late 86 rotor is mounted to the hub, and then a late caliper is used, that might work, I have never tried it, Mike K. would likely know, but I am talking about 2wd though.

I do know the 85 rotors and calipers are different than the late 86 stuff, but I also know that the 1990 V6 hardbody dual piston calipers will fit on the late 1986 spindle, the Pathfinder dual piston calipers are the same as the hardbody dual piston calipers.

[Scgreen620]

I upgraded my 620 to the 88v6 2wheel drive i just swapped from top ball joint to lower ball joint slip in like butter connect the hose and batabing bata boom

 

 

I do recommend rebuilding them you don't know how bad they are ,.....

[datzenmike]

Any thoughts on doing drilled/slotted or both - street use only.

 

Is there a difference between the brake rotors from 4WD and RWD?

Drilling used to actually have a purpose back in the 50s and 60s but today's brakes do not need it. Still, people that don't know better see the holes and think it's an upgrade racing thing. Holes encourage cracks from heat stress and they remove metal reducing the thermal inertia or the amount of heat that can be absorbed by sudden emergency braking. A drilled rotor will over heat sooner. I see cross drilled rotors and shake my head that they make them and that people actually buy them. Oh well....

 

I think the later vented rotor is a different part number between the 2wd and 4x4.

 

 

Get the D-21 Hardbody spindle with all this on it.

[Lockleaf]

Mike you are only half right. The high performance world has long recognized that fully punched holes/slots create more issues than benefits.

 

However, dimpling, or slotting them only halfway through is extremely common practice in Indy, Nascar, Lemans, WRC etc. It's not just about cooling, but also about high temperature outgassing from the pads. Unsprung weight reduction, even in ounces, also matters to these people.

 

I suppose you will argue that they just do that so the fans will think they are cool.

[datzenmike]

No, the out gassing is a thing of the past.... at least for non racing pads. No one drives to the point that their rotors are orange hot on the street. Drilled rotors are like hood pins on the front of a 240Z. ;)

[Crytek89]

As always, I can always count on you guys for amazing, informative answers!

 

The pathfinder does seem to be a good option and that write-up is really thorough, thanks for digging it up!