1970 challenger rt front axle drum brake conversion to disc brakes

[Detroit_v71]

Hello

I am looking for advice on converting the steer axle drum drakes to disc brakes.

What is the best conversion kit out there?

Has anyone used the leeds conversion kit?
I have attached a picture of the kit I was thinking about installing.

Thanks for the help

Trevor

[Dakota]

The answer(s) to your question really depends on your budget and what you're going to be doing with the car, as brake upgrades are one of those things that you can easily spend megabucks on.   Another factor to consider is the size of the rim you will be using as most disc brake aftermarket upgrades will not fit under stock 14 or 15" rims.

I have a 70 Challenger that came with power drum brakes on all 4 corners.  I don't do any performance driving, so a basic conversion kit from Right Stuff Braking (see link below) worked fine for me.  If I remember correctly, the master cylinder had to be changed too because of the switch to discs.   I kept the drums on the rear end.

After working through a series of troubleshooting issues involving the length of the pin coming out of the brake booster and addressing engine vacuum which was too low to provide the "power" to the power brakes, the brake system works fine.

https://rpui.com/the-right-stuff/

There are other routes to make a disc conversion...this worked for me.

[RUNCHARGER]

I like the bulletproof, factory based disc brake setups. Cheap and troublefree. Follow the link to Dr. Diff, he won't steer you wrong, lots of us have dealt with him for years.
Interesting handle, this is something I helped repower a few years ago.

https://www.doctordiff.com/brakes/

[Detroit_v71]

That's awesome,  I have never pulled and engine out of a boat yet.  Is that a 8v92?  I am a diesel mechanic and work on some older screaming Jimmies.

[RUNCHARGER]

It was quite a job. There were 2 of them so we had to pull the one out, then go through the window to put the second one in the 1st one's spot then pull it out. My friend thought we'd have to pull the top ends off but I measured and we had about 1.5" to spare and I didn't feel like lugging all the parts out after pulling them off then reassembling them. 8V92's, he repowered with John Deeres because the Jimmies smoked too much for him. He tried to save fuel and idled them too much I told him, they like to run hard. Cool engines and still lots in use doing their thing.

[erik70rt]

I'm going to do this conversion, too.  But I plan on doing a factory setup with manual discs.  I know the factory never had a manual disc setup on a '70 e-body, so my question is if I just get the disc master cylinder can I put it on without the vacuum booster and it still work properly?

[CHL2T]

I put manual discs from a 74 onto my 70, used the original manual drum MS and the brakes were terrible, changed it out with a disc MS and the difference is night and day.
I'm not sure if the disc MS was for manual or power as it was in a parts lot that I bought 

[Duodec]

Drum brake master cylinders have roughly equal size reservoirs and chambers so they push out similar fluid volumes to both circuits when you press the brake pedal.  Disk brake cylinders have a significantly larger reservoir and chamber for the front disk calipers and push out more fluid to them than to the rear wheel cylinders.

I haven't seen a setup for 4-wheel disks but its likely similar to a front disk/rear drum because the front setups remain the primary, and usually larger, brakes so would probably need more fluid to operate.

[Dodgey1]

Am I right that the 10.95" discs will fit the Stock 14" Rallye Rims on a 70 R/T?

[Mr Cuda]

I'm another manual disc brake user. I've converted 6 of my drum cars to manual disc with the 73- 74 master cylinder. Same pedal effort as manual drum, only the car stops.
I prefer the factory setup over the wilwood set i have. It's the drum conversion setup.

Side note,  my 76 dodge pickup is factory manual disc brake and works great.

[GrandpaKevin]

I converted from manual front drums to manual front discs on the wife's car using this kit
https://piratejack.net/dbk6272-1962-1972-mopar-b-body-e-body-stock-height-disc-brake-conversion-kit/

I used an aluminum master cylinder and matching prop valve from Dr. Diff.
I installed all new brake lines front to back and rebuilt the rear brakes.
I switched to DOT 5 fluid

The brakes have been trouble free and have worked great for the last 7 years

The only issue I had was when I test fitted 15x8 wheels on the front the calipers rubbed the inside of the wheel.
My 15x7 wheels fit no problem.
I removed a little material from the calipers and the 15x8 wheel fit great.

I bought the same conversion kit to do my Challengers brakes this year.