Sandblasting

Obviously, when you tear external parts from a 15-year old car they are not going to look like new but realistically the brakes and hubs from my MX-5 were not in a bad state and could have been used as-is. But where is the "fun" in that? I had originally planned to either buy myself a small sandblasting cabinet (more expense) or nip down to a friend's workshop and us his, however, the discovery of a hand-held sandblasting gun and a huge compressor at work unleashed the inner cheapskate in me. A few things I have learned:

• Sandblasting without a cabinet is not pleasant
• Doing it after work, in winter, in the dark, is worse
• No matter what you try to keep it out, sand will get into your eyes, ears and nose...
• ...and down your back, and in your shoes, and your hair
• You can quite easily turn the area directly outside a fire exit into a small beach

Front caliper piston removal

Before anything can be sandblasted though, it must be stripped down to its constituent parts. The brake calipers were fairly simple, the fronts just needing some compressed air to get the pistons out and a screwdriver to prise out the seals. The rears were a bit more complicated, with the pistons needing to be unscrewed from the handbrake adjustment mechanism, but once done blasting could commence. Considering they are relatively small, these parts take a while to blast as they are a very complicated shape with a deceptively large surface area. They also start to rust immediately afterwards, so they need painting or powder-coating pretty quickly. I painted mine and am very happy with the results. I used a brush-on caliper paint, which is very thin and tends to run easily, but with patience and multiple coats, the finish is very nice.

Before, after and painted

The rear hubs were a little more work. I wanted to replace the bearings, so the wheel hubs had to be removed from the main uprights. This was a simple case of placing an appropriately sized impact socket on each hub shaft from the rear and hitting them repeatedly with an FBH (... Big Hammer). The hubs came out, but unfortunately with the inner races of the bearings still attached to them.

Impact socket from behind

Now, I was prepared for this, having done plenty of research (well, watching a couple of YouTube videos and reading some forum posts) and the wisdom of the internet surmised that you could remove this half of the bearing with a hammer and a flat bolster of some kind to get in the join between the two parts and prise them apart. Well, I think I need to correct the internet on this point, because two ruined bolsters and a lot of swearing proves you can't. A little lateral thinking is actually required: A wheel bearing is made of hardened steel and whilst very strong, it's also relatively brittle, so a score line with a grinder and then a single whack with a hammer and bolster splits it like butter. The outer races still in the main uprights were then removed in much the same way as the hubs, just with a slightly bigger impact socket.

This does not work

This does though

At this point I also cut off the old dust guards as they spoilt the look of the hubs. The only other parts to remove were the old wishbone bearings, which was simply accomplished by bodging a 51mm hole saw and G-clamp together to push them out.

Bush removal - simples

Old bush and it's replacement

Once sandblasted, I used an etch primer to get a good bind to the metal and then a gloss black finish to match the wishbones. Reassembly was straightforward; luckily for me a colleague at work owns a hydraulic press, so he inserted the new bearings for me and I fitted some nice new strongflex poly bushes to the top mounts. The only other modification required was the addition of a length of tube to reduce the size of the bolt holes on the bottom of each upright as the GBS wishbone system is based on 10mm bolts whereas the original Mazda was 14mm.

Before, after and painted

I think the finished result is rather good.