Hi. I have a 1977 FJ40 with 78 power steering. I’m converting the rear drums to disks but have no idea of what kit to use or what else I need to do.
If you can help guide me through the process I’d be grateful.
Also, fronts are discs but I want to redo them too. Should I replace or rebuild the calipers and where to get them and new discs. Thanks.
As has been mentioned, there are several kits to do this, or you can assemble the pieces to do it yourself. At the time (13 years ago?) I used a kit from Man-A-Fre. As has been mentioned, you can get kits from several places. All of the kits use chevy Monte Carlo calipers. @Poser makes good brackets also, if you want to just buy the monte carlo calipers seperately. There are threads on this conversion in the 40 FAQ and/or here in the forum. If you can't find them, let me know. It's pretty much a bolt-up procedure. As long as you're taking off the drum brakes and related parts, now would be a good time to replace the rear axle seals, and your wheel bearings for that matter if there is any doubt at all as to their condition.
The stock front calipers are adequate, and if they're in decent condition there's nothing wrong with just putting new pads on and running them. A reasonably common upgrade is to replace the stock calipers with dual-piston 4Runner calipers. I haven't done this yet but would like to. There are threads on that here also.
The stock master cylinder will work with the rear disc conversion, and I ran mine that way for years, but found it a huge improvement after I replaced my stock master with a non-ABS FZJ80 master cylinder. If you do that, you will probably have to bend and probably do some cutting and flaring of your brake lines to fit. You will also want to run a proportioning valve for the rear brakes in either case.
As you can see, the rear disc conversion, while fairly simple in itself, can quickly take you down a long rabbit hole if you're not careful! Don't let all this overwhelm you; just giving you some options to think about depending on your budget and desire to work on your Cruiser.