(1) When locating REAR hubs at a junkyard, you might as well take the entire rear hub assembly because it will be very hard to disassemble at the yard.   Just remove the drive shaft nut (22mm and a large pry bar!), tap out the drive shaft, and remove the three bolts that attach the assembly to the suspension and take it all home. 

    This is also helpful because if you don’t want to, you don’t have to take the assembly apart! By this I mean that you can remove the original hub assembly off your car and replace them with the assembly from the yard without having to break the seals on the rear bearings. This will same time and money! Time because taking the rear bearings apart is rather difficult without proper tools, and money because new bearings cost about $50 a piece and have to be pressed in with a machine.  The only problem with this is that you’re assuming that the rear bearings are in good shape. Which the usually are!

(2) If you get your FRONT hubs from a junkyard, remember to take the bearings and keep them in order! This is important because they are matched to the races inside the hub and these races are not meant to be removed. Mazdatrix has instructions on their web page on how to replace these bearings. But if the bearings are in decent shape, I wouldn’t worry about replacing them. Just clean them up and repack’em!

    Also note that 89-91 GXL models did not come with the 4-piston calipers.  They came with single piston calipers on five bolt hubs.  To switch these cars to the 4-piston calipers you will need: The brake rotors, the calipers, and brake lines.

(3) There are two types of 5-bolt REAR calipers and disks for the second generation. Vented and Non-Vented. Either will work, but obviously the vented is better (Usually found on TII models and early GXLs). Be careful when mixing and matching parts from different locations because the vented disks require calipers that open much wider than the solid non-vented disks.  

Before you start to tear your car apart, I would strongly suggest that you get all of your parts ready to install before hand.

FRONT HUBS:

You should have already cleaned the FRONT 5-bolt hub that you got from the junkyard. It’s up to you if you want to spend the money to replace the disk rotors. They can cost anywhere from $50 to $200 a piece for new ones!  I reused the ones from the yard b/c they were in great shape and well above the minimum thickness (that thickness is stamped in the rotor itself). If you want to change them, now is the time!

Here is a helpful hint: If you want to get the inner bearing seal (The rubber that holds the grease in the hub...) out of the hub without killing it, perform this little trick: Take the large washer and nut that hold the hub on and screw them onto the spindle. Then take the hub (While holding the studs towards you) and place it over the nut and washer that is on the spindle. Then quickly jerk the hub towards you! What you are doing here is using the washer to hit the bearing inside if the hub. This will cause the seal and bearing will pop out instantly!

The brake calipers are a whole different story. I’m not going to go into how to inspect and repair the brake caliper seals. You can buy the repair kit from Mazdatrix if you need to fix a leaky caliper, and full instructions are given in the second generation Hayes Manual for the RX-7 about how to repair a caliper.

REAR HUBS:

I didn’t even bother taking my rear hubs apart. I brought them home from the yard, removed the disk rotor from the hub and cleaned things up as best as I could. After that, I reinstalled the disk and used them ‘as is’.

CUTTING THE ROTORS:

This is another option that you have while you have the disks off the car.  I had my front disk rotors cut at local brake shop for $20 a piece.  The rear rotors will in great shape and I decided not to cut them because this will shorten the overall life of the disk. 

First thing you’ve got to do is get the car off the ground and remove the tires. You can do the front and rear separate, but it is easier to bleed the brakes latter on when all four corners are off the ground. Once the car is stable, start by spaying WD-40 on everything! Most of these bolts probably haven’t been turned since they were put on the car, and there are a couple places where you have steel in contact with aluminum causing things to stick… A good example of this is the rear caliper mounting bolts. They pass through the aluminum hub assembly and once water gets in there, its tough to get them out in one piece.

FRONT

Once everything is soaking in WD, start on the front calipers. Remove the 2 clips that hold the brake line in place. Then disconnect the brake line at the point where the line starts to go in to the engine compartment. Next remove the two bolts that hold the caliper on. The hub is next. Pry off the dust cap and remove the cotter pin and bolt that holds the hub on. What you have left is the spindle and the brake dust cover. Clean those up till they are spotless.

Now that the spindle is clean, you can start replacing everything. The order is just the reverse of before. First the hub, Then the caliper, Finally the brake line.

REAR

Removal of the rear hubs is more difficult than the front. First thing to do is pop out the dent in the nut that holds the drive shaft. I used a hammer and nail. This is important if you want to reuse the nut! Next you remove this nut with a very large pry bar.  Then you will tap the drive shaft loose with a hammer.  (The bigger the hammer the better!). Then you have to remove the three bolts that hold the assembly on. It’s tricky to do with the brake dust shield in place, but it can be done! Once they are removed the hub will practically fall off.

Now its time to install the new five bolt hub. At this point I spread a little grease on the drive shaft teeth. I did this because I had trouble removing one of my old hubs.   Rust had formed on the teeth of the drive shaft and I figured the grease would keep this from reoccurring.

Installation is just the opposite of removal. Replace the three bolts that hold the hub on. Install the drive shaft washer and nut. Dent the nut to keep it from coming off. Then install the calipers; hook up the brake line and parking brake and your ready to bleed!

Bleeding the brakes is simple. Find a piece of hose that will fit over the brake bleeder nut. Start at the caliper farthest away from the master cylinder. That would be the right rear. The rear calipers have 2 bleeders. Start with the one on the bottom. (You have to bleed both of them because this is a new caliper!)  Place the hose on the nut, run the hose into a jar of brake fluid. Have someone pump and hold the brakes then the person at the caliper loosens the nut. Then you retighten the nut and repeat! Watch for air bubbles coming out of the hose, also watch the liquid and make sure the stuff coming out is clean. If it’s not, your not done bleeding the line. This process is then repeated at all four calipers. Remember to keep and eye on the fluid reservoir and refill it before you start pumping air into the brake lines!