rear disk brake upgrade

The previous article discussed the choices in rear disk upgrades, now we'll put it together and see if it works.

The parts for this include:
89-94 (gen3) Maxima rear struts with disk brake brackets
89-94 Maxima caliper brackets and calipers
89-94 Maxima brake pads
89-94 Maxima parking brake cables right and left
4 lug hubs from Axxess or Stanza
93-01 Altima 4 lug rear rotors

You will also need the backing shims for the pads, the slider/guide shims for the pads and possibly the top shim for the caliper that presses the pads down into place. You can buy the complete hardware kit for a 89-94 Maxima for about $16 or clean up the old stuff if you have it. Some higher end pads have internal backing shims but the guide shim things are still required. The width of the guide shims is different for gen2 and 3 Maxima but they swap out fine.

The parts store had the wrong pads for a gen3 Maxima so I had to get a pads for a gen2 Maxima. The product numbers for the gen2 pads and 93-97 Altima rotors that fit from Autozone are below.

If you pulled your own parts you can probably figure out the installation but we'll go over it here for good measure. The tools you'll need are simple, the impact gun is not required, the breaker bar is. You'll also want some vise grips and heavy pliers for swapping the parking brake cable brackets.

Start by loosening the 30mm wheel nut and lug nuts with the car on the ground. Jack the car up and support with jack stands. There is a jack point in the rear center but I use the points near each wheel instead. Careful not to use the body as it will bend, see picture below.

Remove the wheel.
Release parking brake handle.
Use 8mm bolts to pop the stuck drum off if needed.
Remove 30mm nut and hub.
Tear out old drum brake crap. remove drum backing plate and e-brake cable.
Disconnect brake hose with flare nut wrench and place container below to catch spill.
Disconnect lower suspension linkage but leave main horizontal pin slightly engaged to hold up the strut.
Axxess the strut upper nuts below the rear speaker grille and rubber boot. Remove nuts.
Remove horizontal pin and catch the 25 pound strut before it hits your toes.

The base of the gen3 Maxima strut is wider where the horizontal bolt goes so you will need to make sure you get the wider horizontal bolt along with the strut. The Axxess bolt is too short.

Use a jack to slowly lift the strut into place while guiding the upper strut studs into their holes. Slap it all back together using the new parts and getting torque values from the Axxess manual available in the links section here.

Clean the new rotors with soap, water and brakleen. Apply a small amount of brake grease to the underside of the rotor where it contacts the hub to help it from getting stuck next time. Remove the caliper pins and inspect the boots for leaks then apply a generous amount of grease to the pins and reseal the boots onto the caliper bracket. Apply grease to the brake pad guides making sure no exxess gets into pads or rotor. Also apply brake grease to edge of pads where it contacts guides and use either grease or brake quiet on the backs of the pads where they contact the piston/caliper. The Axxess manual shows how the brake shims are to be installed on the backs of the pads in pairs but getting one on each pad is better than none.

And here is the final assembly !

The stock spare tire still fits this rear disk upgrade but does not fit the front disk upgrade posted earlier at this blog.

Next, lay the Axxess parking brake cable beside the new ones from the Maxima and use pliers and vise grips to uncurl and remove the mounting brackets. Transfer the brackets to the new cable in the same positions. Leave the brackets slightly loose so you can fine tune them.

Connect the cables at the parking brake balance bar. There is no need to remove the Axxess parking brake handle. Attach the cable brackets to the body with the mounting bolts and connect the cable at each wheel.

Jack up the front of the car and support with stands to facilitate brake bleeding.

Now is a good time for a full brake fluid change. Use a syringe to drain the brake fluid reservoir or simply pump the fluid through one of the wheels if it looks clean enough. Fill the system with new dot3 fluid and use a bleeder bottle to get the air out at each wheel. Pump em up and crack the valve then retighten. Use that flare nut wrench you bought to save your bleeder valves and knuckles. Let it sit for a while and bleed em again. Bleeding order, left rear, right front, right rear, left front.

If the pedal is feeling firm then put the wheels back on and "bed" the brake pads by driving the car at 10mph and braking to 1mph, 5 times. Then do the same at 20mph to 1mph and then at 60mph to 1mph. Avoid any hard stops during the brake break in period. Test the parking brake and adjust it with the small nut hidden on top of the parking brake lever under the boot.

So how did it all work? It feels great driving and stops on a dime, especially with the front brake upgrade from earlier. I'm confident the rear disks will have less fade and better stopping power than the drums. In an informal test  performing a panic brake on gravel (pic below), the rear wheels did not lock up, which is good. During sustained braking tests the rear rotor got sizzling hot so they are working for sure.

The mix and match Maxima struts really fit perfectly. You can see the car body sits slightly low in front but the high wheel arch in front balances the look. Hopefully a set of lowering springs will take the car straight down so the rear wheels will tuck and the front will have a tiny fender gap.

It would be best to attach some high pressure brake gauges to each wheel to check the front to rear brake bias at different pedal pressures. Ideally a 50/50 bias is good at low pressures to preserve the front brakes but at higher pressures the fronts move to the 70/30 range to avoid rear lockup. In line proportioning valves and possibly an adjustment of the load sensing valve in the Axxess may be required, but for now the brakes seem quite good. We'll certainly need a 4 wheel alignment soon though.

rear disk and suspension upgrade options

A rear disk brake upgrade is a popular modification as it improves braking performance and simplifies maintenance. It is also an affordable upgrade as most of the parts are available at your local salvage yard. There are a couple Nissan rear disk setups that will work with the rear suspension of the Axxess but some fit differently than others.

Suspension upgrades are also in demand and  although some may consider higher towing capacity or a comfortable ride an upgrade, we will concentrate on a lower and stiffer suspension. The goal is better handling, less body roll and a lower stance. Unfortunately, there are no performance suspension packages for the Axxess, go figure. There are also no performance cars that have the same suspension as the Axxess.

The only Nissan I've found that has the same 6.75" springs front and back as the Axxess and also has the same strut mount points is the 85-88 (gen2) Maxima. Of course there are no performance springs or adjustable coilovers available for the gen2 maxima either.

It is possible to do a rear disk upgrade upgrade from the gen2 Maxima but the only affordable option to lower it would be to cut the original springs, which would not stiffen the ride and is often considered unsafe. Another option might be custom made springs but that may not be affordable.

There are a couple other considerations if you do decide to do the gen2 Maxima rear disk upgrade. The rotors and hubs are one piece and about twice the cost of standalone rotors. Another consideration is the emergency brake cable which is a different design than the Axxess. The e-brake cable from a later 89-94 (gen3) maxima with rear disk brakes does fit the Axxess and also works with the gen2 Maxima disk calipers.

Axxess on left and Maxima gen2 on right

One issue with 85-88 gen2 Maxima disk conversion is that the rotor/hub assembly will not fit onto an Axxess axle as the wheel bearings are completely different. You would need to also get the gen2 maxima struts and install the complete unit into the Axxess along with the gen3 e-brake cable.

Another, and probably better option is to use the rear suspension parts from a 89-94 (gen3) maxima which also fit the Axxess without modification.

The 89-94 (gen3) Maxima has a 6.75" spring up front like the Axxess but has a 5.5" spring in the rear. Of major importance is that there are a couple performance lowering springs for the gen3 maxima  although there are no true adjustable coilovers for the rear available. The gen3 Maxima also has widely available replacement rotors and the same parking brake setup as the axxess. The gen3 maxima is also far more common in most salvage yards.

The gen3 Maxima is a 5 lug hub but the Axxess hub will slip right onto the gen3 Maxima axle as will the 4 lug hub from the 90-92 Stanza. The 90-92 Stanza also has the same rear strut and disk brake as the gen3 Maxima, if you can find one with rear disks. The Stanza e-brake cable setup has not been verified yet. If you want to do a 5 lug conversion, now is the time. Keep the gen3 Maxima rear hubs and find some 5 lug front hubs or compete knuckle that fits the Axxess, probably from the same gen3 Maxima.

One advantage the early gen2 Maxima rear rotor has over the gen3 Maxima is its larger size. It is 283mm compared to the 256mm of the gen3 maxima and many other nissan models. The early Maxima achieves this by using a taller caliper bracket. The caliper itself and the disk brake mounting bracket attached to the axle itself are close to the same on both models.

The gen2 85-88 Maxima is on the left in all these images and the gen3 89-94 Maxima is on the right

It might be possible to put gen2 brackets on your gen3 setup to get larger rotors and use 84-85 300zx rotors. I decided to stay with the rotors that matched the gen3 Maxima 5 lug rotors exactly but were 4 lug, and that was the 93-97 Altima rotors, same year and model as up front.

One more difference between the gen 2 and 3 maxima rear struts is track width. The Gen3 rear struts have less material and set the rear wheels slightly closer together than the gen2 or even the Axxess. This could be a benefit as drawing the wheels closer improves fender clearance.

The picture below shows the Axxess rear axle on the left and the gen3 Maxima on the right. You can see the extra grey colored metal between the axle and the strut tube compared to the gen3. You may also notice the absence of the disk brake mounting 'ring' at the base of the axle on the Axxess. The Axxess with it's drum brakes does not have this ring which would move the Axess axle even further out. The absence of this ring on the Axxess also means you cannot simply do a gen3 Maxima rear disk upgrade by simply adding the disk mounting bracket, caliper bracket and caliper, you would need to replace the whole strut instead.

Here is the gen2 (on left) and the gen3 Maxima axles. You can see the wider track of the gen2 as well as the unusual early axle stub that is not compatible with the Axxess or gen3 Maxima.

Will all of this work with a stock master brake cylinder and still provide proper brake balance? We'll see soon enough.