Disc brake conversion (1 Viewer)

[cruiserguysc]

OK so the time is finally come for me to pull the trigger on one of my 40’s. I’ve decided that starting this spring I am going to take the top off one of mine and daily Drive. It is definitely not a long commute to work and well to be honest the cruiser would sit in the parking lot for well over nine hours.

However, I am tired of pumping the brakes! I am going to start with the front end. My question is has anyone experienced the conversion kit purchased from JT outfitters? Are there any opinions pro or con? Any other options? Thanks in advance.

 

[mtrdud]

Lots of info on this in the FAQ section but I would definitely recommend a disc swap. I have used the JT kit long ago but there are better options IMO.

 

[RevISK]

If it were me, I’d get it all from @cruiseroutfit cruiserteq.com.

You’ll know it’s quality stuff and you’ll have a support system if things go awry.

My truck came with disc brakes so I can’t offer anything more than the above.

 

[cruiseroutfit]

My diatribe on donor parts for the disc brake conversion

Tech Talk: Ultimate 40/55 Series Disc Brake Conversion Parts Thread (Work in Progress)

Skip anything that has you reusing course spline birfield outer axle and uses adapters to fit GM calipers and rotors. Like hard pass skip. These require you to re-use your course spline (low strength) outer birf joint and free-wheel hubs, both of which have no options for upgrades. If you have a...

forum.ih8mud.com

 

[peesalot]

x300 on using Toyota parts, the JT kits works, I know cause I put one on, however it requires modification and IMO the drums work just as good when properly set up. Kurt or Georg for this kit.

 

[Mark Jennings]

I use the Monte Carlo brake set up on my 68. The only thing I got from JT were the front and Rear adaptor plates and the 3 bolt to 4 bolt Master Cylinder adaptor….I don’t think the adaptors come from JT anyway, they just resell someone else’s product. Everything else came from Summit, WillWood, Amazon and CARid. And the braided hoses came from Classic Tube.
I also installed longer wheel studs to ensure the rotor thickness did not interfere with lug nut engagement, these were Milesian, and from E-Bay…just not a lot of optional lengths for 12 mm studs.
A couple of things to remember is that the front and rear axle flanges will need to be turned down to allow the Chevy rotors to fit correctly and the rear caliper mounting plates may require some milling work to ensure the calipers center correctly on the rotors.
I do NOT run power brakes but use WillWood D154 BP10 pads. Theses give you a good solid feel and unlike drums…do not fade when hot or when wet. My setup uses a Toyota T100, 1” master cylinder with a simple a proportioning valve to the rear circuit and 2 PSI residual check valves in both the front and rear circuits. If you go this rout, you definitely need the the proportioning valve AND the residual check valves….keeps the pedal high and tight and keeps the back end from passing the front end when you ‘Stand’ on the breaks.
I won’t lie to you, without power assist, you need some leg to get her to Lock Up, but I find non-power gives better feedback through the peddle.
I got the rotors from Summit….intended for 89 K1500 Chevy 4WD front brakes, I got the Calipers from CARid….GM metric calipers for 78 and newer mid size Chevy’s. Everything else…as listed above.
Have Fun, you will have no regrets going to disks…

Rear adaptor plates before and after.

Residual valves (blue things)

Proportioning Valve (Black, mounted to right of T100 master cylinder.

 

[troutbum4]

find a donor toyota truck axle from the 80's and you will end up being much happier

 

[archie73]

I have the mini truck knuckles, ifs calipers and a vented disc(fj60?) up front. Low maintenance and they line up perfectly. I can’t comment one the JTO kit, but the Toyota stuff works great. Even better after I got a working booster!! For true low maintenance swap the rear brakes to @Poser rear kit.

 

[Unimogguy]

Get the upgraded axles Kurt talks about in his post. You might get lucky on the axles and find a later model set (1/79 or later) with the better gear ratio (3.70) if this is going to mainly be a highway Cruiser? I would swap the thirds around in any used axles I got. Front to rear and rear to front.

Then if you’re wanting rear disc brakes this is the go to: TOYOTA TRUCK AND LAND CRUISER REAR DISC BRAKES - https://www.tsmmfg.net/toyota-truck-land-cruiser-complete-rear-disc-brake-kits.html
Buy them thru Kurt since he was kind enough to post here and make the informative axle post previously!

 

[AirFuelRatioMan]

Ok guys, I need some help please. I have a 1985 FJ70, South American model made in Venezuela. I have front drum brakes, but nothing like what we had in U.S. or even Australia. It is some hybrid setup, where the brake line goes into one cylinder, then OUT the SAME cylinder, to feed the other.

I had the truck on jack stands for over a month looking for new cylinders when I found a couple leaking, and did not have any luck. I rebuilt the cylinders which were heavily pitted, and that has lasted a year but now they are leaking again and I’m done with this setup. Even a purist wouldn’t be able to get the parts needed to fix it.

I would like to buy the brackets on JTOutfitters, however, I am uncertain that they will work. Due to, my axle uses the “long” spindles, not the short ones and short wheel hubs that the kit is designed for…..

The big question is, is the wheel surface mount on the short spindle / wheel bearing hubs in the same location / offset as the long spindle / wheel bearing hubs??

More simply put, is the wheel going to be in the exact same position regardless of short or long spindle / hubs?

This will tell me if the disk brake conversion brackets will work, and the rotor will be in the right location.

 

[bikersmurf]

I’ve read reports that the JT front brackets have bent or broken. I can’t verify the statements because I’ve not even seen them in person. The course spline birfields are also weaker.
Around ‘94 I converted my front brakes to disc brakes. I bought a complete ‘77 Fj40 axle and plunked it down beside my truck and started mixing and matching parts. I kept the ‘74 center housing with 4.11 gears and swapped on the inner axles, knuckles, calipers, backing plates, rotors, and hubs.

First test drive I discovered that the rear brakes would lock if I braked hard. I called a couple people I knew who had 40s and learned that I needed to add a brake proportioning valve to the rear brake circuit. Grabbed one from the local wrecker, and it resolved that problem. Years later I learned that the 10 lb residual valve should be removed from the front circuit… so what the heck, I pulled it. Nothing much but what the heck,
That cheap $20 set of pads lasted 20 years and 100,000 miles.

Ok guys, I need some help please. I have a 1985 FJ70, South American model made in Venezuela. I have front drum brakes, but nothing like what we had in U.S. or even Australia. It is some hybrid setup, where the brake line goes into one cylinder, then OUT the SAME cylinder, to feed the other.

I had the truck on jack stands for over a month looking for new cylinders when I found a couple leaking, and did not have any luck. I rebuilt the cylinders which were heavily pitted, and that has lasted a year but now they are leaking again and I’m done with this setup. Even a purist wouldn’t be able to get the parts needed to fix it.

I would like to buy the brackets on JTOutfitters, however, I am uncertain that they will work. Due to, my axle uses the “long” spindles, not the short ones and short wheel hubs that the kit is designed for…..

The big question is, is the wheel surface mount on the short spindle / wheel bearing hubs in the same location / offset as the long spindle / wheel bearing hubs??

More simply put, is the wheel going to be in the exact same position regardless of short or long spindle / hubs?

This will tell me if the disk brake conversion brackets will work, and the rotor will be in the right location.

View attachment 3777949

View attachment 3777950

I suspect the spacing would be the same, but can’t be certain what was changed when the built it, for the rear, I’d buy brake adapter @Poser and modify the spacers if need be.

For the front, if they are Toyota axles, I’d get some knuckles and carefully compare and see if they bolt on.

 

[AirFuelRatioMan]

I’ve read reports that the JT front brackets have bent or broken. I can’t verify the statements because I’ve not even seen them in person. The course spline birfields are also weaker.
Around ‘94 I converted my front brakes to disc brakes. I bought a complete ‘77 Fj40 axle and plunked it down beside my truck and started mixing and matching parts. I kept the ‘74 center housing with 4.11 gears and swapped on the inner axles, knuckles, calipers, backing plates, rotors, and hubs.

First test drive I discovered that the rear brakes would lock if I braked hard. I called a couple people I knew who had 40s and learned that I needed to add a brake proportioning valve to the rear brake circuit. Grabbed one from the local wrecker, and it resolved that problem. Years later I learned that the 10 lb residual valve should be removed from the front circuit… so what the heck, I pulled it. Nothing much but what the heck,
That cheap $20 set of pads lasted 20 years and 100,000 miles.


I suspect the spacing would be the same, but can’t be certain what was changed when the built it, for the rear, I’d buy brake adapter @Poser and modify the spacers if need be.

For the front, if they are Toyota axles, I’d get some knuckles and carefully compare and see if they bolt on.

Well, decided not to go with the JtOutfitters bracket for the Chevy parts conversion. Also, finding parts from a donor with disc brakes is not looking good. Looks like if I changed to disk brake knuckles I’d have to source them from the States and pay 12.00 per pound shipping So I stumbled across an option that allows the use of the knuckles I have, which is to source IFS hubs, rotors and calipers from a 4Runner and buy or make a bracket (safer as it’s a flat piece with no welding).

I’ve read many dislike the smaller 4Runner brakes, but with my 15 inch rims, it’s what I’ll have to go with…