drum brake technical question (1 Viewer)

[Lifelong40Fan]

All, I have a '65 FJ45 that eventually I'm planning to do a disc brake front axle swap on from an FJ40, but that's at least a month or 2 in the future. For now, driving the truck is a bit hairy with the drums. I swapped a new rear axle with rebuilt wheel cylinders, so the back is good. The front is terrible. Here's my issue: I'm thinking of improving the braking by rebuilding the front wheel cylinders, separating the front and rear brake lines and adding a brake booster and master cylinder from an FJ60, which, of course, has front discs. So, my question is: will having a booster and MC from a 60 cause problems for the front drums? Once I have discs up front, I'll end with this booster and MC, so just thinking about getting those in now with my front drums while I build the front axle.

Cheers,
Mike

 

[CruisinGA]

drums require a residual valve which the FJ60 master does not have. I would not do it. I also would not mess with front drums. disk and don't look back.
I wasted way too much time f**** around with drums before I went to 4wheel disk.

 

[70fj40]

It would be a much easier and quicker fix to go ahead and rebuild the front cylinders like you are planning and then adjust the brake shoes. If done correctly this will give you good brakes until you decide you want to tackle a disc swap. Drum brakes work well when the cylinders are in good shape and adjusted properly.

 

[tornadoalleycruiser]

Your $ and time ahead to just do the correct front disk toyota conversion. If you add up what it is going to cost both time and $ to rebuild the front drums it will come out almost the same as a disk conversion. Finding a core is the hardest part. Mini, later fj40, later fj55, fj60, fj62 are all donors. Solid axle Mini requires cutting the drivers side knuckle arm which takes 5 min. You can run a non boosted master until you get a booster assembly. While I'm not a fan of this particular vendor he has an inexpensive adapter. Tandem Brake Master Cylinder Firewall Adapter for Toyota Land Cruiser FJ40 FJ45 – JT Outfitters - https://www.jtoutfitters.com/product/tandem-brake-master-cylinder-firewall-adapter-for-toyota-land-cruiser-fj40-fj45/
One issue is your oem 65 axle will most likely not have provision for the birf seal and you will most likely need a full donor front axle housing. My guess is you might have ball and claw front axles instead of birfields. Build a new axle, upgrade to 10mm brake lines and roll the whole new axle under at once. Changing to a dual piston master is much safer. Marks off road has an adapter for a booster on the old firewall. Clearance to a carb can be an issue depending on drivetrain.

 

[Lifelong40Fan]

Yeah, I’ve got a donor 40 front disc axle and the booster firewall adapter, just need to build the axle. I’d enjoy safely driving the 45 in the meantime. Guess I’ll just rebuild the front wheel cylinders. Rebuild kits are cheap and easy to add.

 

[Lifelong40Fan]

Rebuilt all the front wheel cylinders - one cylinder was completely seized and several had pistons that were needing a lot of cleaning. Bled the brakes and Adjusted the pads until slight resistance when spinning the mounted tire. Still no pedal unless I pump. Guess I need to adjust the back brakes again. Coming along.