best disc brake conversion?

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Aug 12, 2002
Hi guys,
I'm tired of messing with my drum brakes. I can never seem to get them dialed in and neither can anyone else, so I have decided to switch over to 4 wheel disc. I have been looking into it for a few days and I can't seem to find anyone that makes a decent conversion kit for a 1975 fj-40... At this point I'm not as concerned about price as I am performance. So where can I find a really good conversion, bolt on preferably, :D or any articles explaining the best way to do this job through miscellaneous parts. By the way, is it just my land cruiser being stupid or do they all have braking issues?
see the tech links at top,

click there and look for disk brake conversions.

some pros cons

steering arms:
The '81-'84 J40 steering arms are heavier than '79 and '80 and have the right tie rod taper (which mini, 6-, 70 don't). The other arms are fine (same fat tie rod end) and shims can be used (mini, 60, 70 super fat) or use mini tie rod (explained in tech).

steering arm spacing:
1979 and later ALL top steer LC and mini live axle arms use same spacing and high steer arms can be bought. 76-78 are different spacing (same as drum) and you must make high steer arms

1979-1990 birfields are better than 'odd ball' '76-78 birfields and don't readily take aisin hubs (the best). These days, longfields seem like best upgrade.

mini rotors (79-85) are solid
LC rotors 1976-1998 are vented
-1976-1980 rotors bolt on 5 bolts, 1981+ use wheel studs and 2 bolts, 1990's use just wheel studs (scalloped hubs)

1976-1990 calipers (LC) have one large and one small cylinder (also same parts as 1986-1989 IFS mini)
1990+ calipers have two equal size calipers, but fins on later versions can hurt wheel fitting.
mini 79-85 fit only solid rotors.

aisin, everybody has em so trail spares a plenty

brake master/booster-
I'd say just get a FJ60 booster/master set up. Common, parts for years and years to come, and booster is smaller than the giant late 70's 40/55 one. 75's have expensive masters and the twin reservoir thing gets old. Simply put, they made more J60's

The "best" no expense would be: '81+ arms (dealer ~$90 ea, rare to find parted out), longfields, vented rotors, late model calipers

"better" is mini truck donor with shims $30-$40 for tie rods, swap for new vented rotors, grab IFS calipers instead of std mini (unless you are buying reman).
Or if you want easy bolt on you can buy a kit from Man-A-Fre that is a bolt on so you don't have to pull any hubs or birfields. Just bolt it up and go. But you won't get the heavier birfields this way, you only get disc brakes. If you do only mild off-roading the stock birfields will be fine but if you plan on front locker and heavy off-road use you will want the heavier birfields.
For front, I would do the minitruck disc swap.

For rear, use the JT Outfitters brackets and the Monte Carlo calipers....just plumb in a proportioning valve from Summit.

Cheapest of the options, simple to do, but not a bolt-on-no-work-required setup.
I have a 72 cruiser with 4 wheel drum and I want disc brakes would I need to get a proprtioning valve to convert to disc brakes?
I run my 74 booster and master and no proportioning valve, but mine is about 99% offroad use and IMO it's not as necessary there. If you street the truck much, then the $35 prop valve is nice - otherwise your bias in the rear is too high and they lock up and you slide and spin and do 360's on the road and scare neighboring motorists and....

well, anyways....BTDT.... :D

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