Disc brake conversion for 3/70 FJ40

Joined
Apr 26, 2018
Messages
52
Location
Ft. Worth
I see tons of disc brake conversion posts but almost all are later vehicles than mine. Apparently in 8/70 there were changes made so my 3/70 FJ40 seems to need a little extra. I went to jtoutfitters.com to look at the 4 wheel conversion and it looks nice (although the cost made me vomit in my own mouth). I'm sure their prices are fair, but it's still a tough pill to swallow.

7 of the 8 wheel cylinders I have are leaking or seized so a conversion seems in order but the kit shows it's only for 8/70 - 9/75. I believe my fittings are 10mm, and not the 9mm that was original on the vehicle but it does state I need different line fittings and a dual circuit hydraulic system.

Does anyone have any clue on how to do this? what do I need for a dual circuit hydraulic system and will this be cost prohibitive?

And by the way, thanks to everyone for the help with my carb and ignition problems. All are solved thanks to everyone here.

IMG_20200104_140134.jpg


IMG_20200104_160703.jpg
 

3_puppies

SILVER Star
 
 
 
Joined
Dec 2, 2002
Messages
12,603
Location
Helena MT
do you have a brake booster?
if not you have a single circuit brake system, when the booster was added it went to dual circuit.
a few pics under the hood would help.
it is going to depend on what you want to do, 4 wheel disc? boosted? non boosted? front disc only with rear drum? stay 4 wheel drum?

there are other places to buy parts from than JT.
 
Joined
Apr 14, 2011
Messages
134
Location
Tucson, AZ
I see tons of disc brake conversion posts but almost all are later vehicles than mine. Apparently in 8/70 there were changes made so my 3/70 FJ40 seems to need a little extra. I went to jtoutfitters.com to look at the 4 wheel conversion and it looks nice (although the cost made me vomit in my own mouth). I'm sure their prices are fair, but it's still a tough pill to swallow.

7 of the 8 wheel cylinders I have are leaking or seized so a conversion seems in order but the kit shows it's only for 8/70 - 9/75. I believe my fittings are 10mm, and not the 9mm that was original on the vehicle but it does state I need different line fittings and a dual circuit hydraulic system.

Does anyone have any clue on how to do this? what do I need for a dual circuit hydraulic system and will this be cost prohibitive?

And by the way, thanks to everyone for the help with my carb and ignition problems. All are solved thanks to everyone here.

View attachment 2174098

View attachment 2174099
My FJ-40 is from 7/69. I too "had" the same issues you're describing. Here's what I did. I ordered the new dual master cylinder from Man-A-Fre (Any master cylinder with a power booster will not work for you (without a lot of customization) as the rib from the firewall gets in the way - this one is bolt-on - FJ40 FJ45 Tandem Brake Master Cylinder Conversion Kit For Drum / Drum Configurations 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970 - Landcruiser Parts) Then I added the front and rear disc kits from Man-A-Fre as well. Running the new tubing and installing new 10mm pieces on the tubing wasn't as difficult as it first appeared, but I did purchase a flaring tool from Eastwood that made the job so much easier. (Professional Brake Line Flaring Tool Kit - Eastwood). You won't have the "power assist" without the brake booster, but honestly, the braking was so much better, I'm hooked!
 

69LC

 
Joined
Jan 12, 2008
Messages
2,784
Location
West MI near GVSU
Look up what it takes to use mini truck/4Runner/fj6x knuckles. It’s really not hard to convert and you can use later vented 40 rotors and big piston 4Runner calipers.

It will give you better wheel bearings and birfs.

There are also people here that have kits to use easy to buy gm 1/2 ton rotors and calipers for the rear using @Poser caliper brackets.

If you want to keep your stock tie rod Cruiser Outfitters has tiered end adapters.
 

4Cruisers

SILVER Star
Joined
Apr 2, 2015
Messages
5,317
Look up what it takes to use mini truck/4Runner/fj6x knuckles. It’s really not hard to convert and you can use later vented 40 rotors and big piston 4Runner calipers.
I used FJ60 vented rotors (IIRC same as late FJ40 rotors) and '91 IFS calipers.
 
Joined
Apr 26, 2018
Messages
52
Location
Ft. Worth
I will check these options. I saw JT Outfitters has a whole kit with everything, but everyone says their customer service sucks and that worries me.
 
Joined
Nov 10, 2011
Messages
404
Location
Minnesota
I just pulled everything off an axle. Last post in my build thread. I was gonna sell. PM if you are interested in going that route.
 
Joined
Apr 26, 2018
Messages
52
Location
Ft. Worth
Ok, I decided to stick with the original drum system and rebuild the wheel cylinders. However, I have an issue. The front cylinders went great and all four are rebuilt. The back seems to be the issue.

First, there was some sort of shim in the interior. Is that supposed to be there and is it necessary?

Second, I got this rebuild kit from Cruiser Outfitters and although the front was great, the rear seals don't seem to match.

I will include pics in case someone can tell me what is wrong. Are these incorrect new seals or are my rear cylinders not original?

I put the pics of the old parts on the right and new stuff on the left

Please help. I'm at a loss

IMG_20200111_202306.jpg


IMG_20200111_202339.jpg


IMG_20200111_202353.jpg


IMG_20200111_202454.jpg
 
Top Bottom