Hi again friends. I've been busily solving a lot of lingering issues with this '74, and today I noticed that my brake master cylinder seems to be starting to give out. I could replace it, and it might be wise, I figure, to do the wheel cylinders as well, or else risk blowing them with the confident pressure of the new master.

Then it occurred to me, why not swap in discs for the front with '75-78 parts? I've now read every last thread I can find pertaining to this subject, but having never seen it done before, I'm a little foggy on the details, and of course that's where that pesky devil lives. ...so I'm going to ask a lot of what to some might sound like dumb questions with obvious answers. I'm aware that I'll need a booster, and the accompanying master, rotors, calipers, pads, and related hardware. I also presume that I'll need an appropriate front hubs to mount these rotors onto, and I guess I oughta do the bearings while I have all that off? I've read that the spindles are compatible, but are there things I should know about swapping hubs if I've never done it? The only things I've ever replaced on disc brakes are rotors and pads, so I'm not sure what I'm getting into. Does all of the '75 stuff just bolt on to the '74? What do you call the bit that the caliper attaches to, that's mounted to the steering knuckle? Is that the backing plate? Is it mounted to the steering knuckle? I can't find a diagram anywhere to even know all the parts I need to swap, and which ones will be compatible. Do I need to create mounting points for the booster, or does it mount where the old master cylinder was?? Can anyone refer me to a diagram or photos for reference?I'm compiling a list of available new, lightly used, and reconditioned parts. I'll post it here for evaluation if it's not too much to ask.

Honestly, I do like the hearty solid feeling of drums, and I like that the pads last a long time, but when the wife has driven it, she has locked them up a couple times, being used to ABS discs. Also, this truck visits the cascade range regularly, and there's some long descents where drums could get awful hot. I kind of look forward to better modulation and control. Adding up the cost of converting, next to replacing the necessary drum bits, It doesn't seem like an unreasonable expense if I can figure out how to effectively mount everything.

Suggestions anyone?

 

My truck is a '72.5 and I've gone through the conversion myself. There is a great forum on this site that gave me a check list for the necessary components.
I collected all the parts and had a shop do the work. The only thing that needed modification was the firewall for the brake boost. I believe the holes just needed to be ovalized to provide the proper clearance. Other than that everything bolted up. I used parts off a '77.

If you are interested, I do have most of the components available. I believe I have the booster somewhere in storage too.

 

Really? Wow, I haven't run across that forum yet. I just searched for different variations of 'disc conversion'.

I'd be very, very happy to find most of the parts all in one place. If you want to message me about it, I'll do my best to make it worth your while. Thanks for responding!

 

This thread has some good info. I referenced this a while back.

https://toyotaminis.com/forum/threads/disc-conversion.16980/#post-184655

 

Nice, thanks! That's some good info about the booster mounting. If I can find all this stuff within my budget, I'm going to undertake the swap adventure. It's more work, but not much additional expense, relative to replacing all the drum parts.

Honestly, I'm not even sure of the production date of this truck, since the 'service parts ID' sticker is nowhere to be found, so I can't get an accurate RPO code to verify parts. I'm not certain which front wheel cylinders I'd need. It's a bit of a hassle. I can't even find a database that will let me extrapolate from the VIN. I just tried to install incorrect inner tie rod ends, from what was suggested in an online parts source, and I have no idea what the correct ones are! Blaaaaargh!!

 

You wont find anything thru the VIN on these old toyotas. The plate under the hood does have some useful info as far as the drivetrain goes.

Production date should be on the vin plate in the door jam

 

I want to say es2093r is your inner tie rods. Rock auto is good for parts like that. If you end up redoing the brakes you'll find the front on rockauto. You need 2 left and 2 right. You'll more then likely need new banjo bolts because of the new cylinders having a shallower thread. I used m10x1 L24. They don't have the springs anymore. There are only 2 springs per brake and they are not hard to get off and on without messing them up. If it comes down to it I can sell you a hardware kit if I can find it.

 

The one I got from Rock Auto that didn't fit was the Delco 45A0289. I couldn't discern any difference between that and the Moog es2093r, but maybe the options on the site are in error. I'm still deciding about the disc options, but that's good to know about the bolts. That would have been a sure snag.

 

The es2093r is used by a few different brands and distributors like O'Reilly's.

 

Just switch over to discs if you can find the parts. Really just need the spindles since the bearings, rotors and calipers can all be had new/rebuilt from Rockauto. Extended Stainless braided lines from LCE for a 79-83 fit up front with no mods.

i used all Moog or Mevotech (same shit) tie rods and ball joints from rockauto.

 

Yeah, I think it's really worth the effort. I'm going for it. Now I'm pricing out rebuilt booster, master cyl, calipers, pistons, hardware, and hey, hoses are sounding like a good idea too. I'll post as it comes together...

 

Run through my build thread, i explained it there.

oh and a booster and master from a 79-83 will fit with a small amount of work. Brake lines will need to be modified but its actually fairly simple

 

If you still have 14's you'll need to go bigger.

 

My "winter wheels" are 14s offset could be whats helping them fit tho

 

Ah, got it. Thanks, that clears up some confusion.

I do have the original steel 14" rims. Are you saying I'll need longer hoses than that?

 

Longer flex brake lines are because of where the the line goes to the caliper.

the wheel size matters because of how much further out the caliper sits than the drum does.

 

So, as I understand it so far, I can use the 75-78 steering knuckle, hubs and backing plate to mount the new calipers onto, with longer hoses to reach. Then I can directly swap in a rebuilt 75-78 booster and master with slight firewall hole adjustment, after moving the clutch cylinder over a bit?

 

Longer than this?



26" Extended Brake Line Kit (2 front 1 rear)

 

As Jetas mentioned, I think all you would need from the parts I have are the spindles. I bought a rebuild kit for the calipers I purchased, but new ones can be found on Rockauto.