RM brakes?

[Jonah D'Avella]

I have a set of RM brakes for a small drum car. they have the six whole large drum adapter. I have wire spoked wheels with five holes. I can get a five hole large drum adapter and use that. If that works, is it possible to used these brakes on a 27?

[Norman Kling]

They are a different size. The small drum cars need a drum made for Rocky Mountain brakes and the band to match. You also need the bolts a little longer than the original and remove the parking brake drum from your wheel and place the larger Rocky Mountain drum next to the wheel spokes then the original parking brake drum inside. You might need shims for the axle ends to move the hub farther out from the backing plate because the parking brake drum will be moved a little closer. Try the hub on first and if nothing scrapes, you do not need the shim, but if it scrapes, install the shim. be sure to tighten the axle nut about 100 ft lbs so it will not wobble on the axle.
The 26-27 rocky mountain brake has a smaller band made to fit around the original 26-27 parking drum.
If your wire wheels are the original 26-27 type you can use band made for 26-27, but if you have a different type wire wheel, you will need to use the type which fits your car.
Norm

[DanTreace]

Quick answer if your ‘small drum’ 09-25 brakes are the modern RM then they won’t fit the 26-27 rear axle backing plate and radius rods as the 2 styles use different bracket castings.

Best to trade them for the 26-27 version, then the brackets and shoes will fit directly on the large outer brake drum and you’ll retain the internal parking/emergency shoes using Ford parts with your Ford wire wheels and wire wheel rear hubs and drums.

[Steve Jelf]

Or you could sell them and buy AC brakes, which work backing up as well as forward. If I remember correctly you are in the almost-state of Franklin. I believe that's hilly enough country to make external brakes in both directions a good idea.

[DanTreace]

Steve

Jonah has a 26-27 touring, the repro AC brakes only fit 09-25 style rear axles.

Good idea on the new disc brake on the rear wire hubs, those new discs will provide extra level of safety.

[Novice]

Jonah. In classified parts. Donne Brown / Dobro1956 has a bunch of ac and rocky mountain brake parts for sale including a set of both five & six hole. wood / wire wheel drums.which may be the parts You need to complete the project.

[Darin Hull]

Steve,

Where can you buy new shoes/pads for AC brakes?

Darin

[Jonah D'Avella]

I thought the five whole drums would work as well. Woll they fit over my existing drums?

[DanTreace]

Jonah

Nope, those 6 hole mount onto the rear of a wood wheel hub.

You can’t place those on the wire wheel drum, as the wire wheel drum is already 11” dia. Plus the wire wheel drum is short stud secured , same short studs that retain the wire wheel. Plus the Ford wire wheel drum (or the 21" wood drum for that matter) are dished and getting another drum on top will cause interference.

When mounting the large 6 hole RM drum, onto only a wood spoke wheel, the rear Ford 8” drum is removed from the hub bolts.

Then the large RM drum is placed on the hub, then the little 8” Ford drum is placed inside it, and the hub bolt nuts secured.

small drum RM copy.jpg (147.75 KiB) Viewed 3346 times

[Original Smith]

AC made a nice accessory braking system for the 26-7's. They aren't easy to find, and unlike the repros, are cable operated, as are the original Rocky Mountain brakes.

[Steve Jelf]

Where can you buy new shoes/pads for AC brakes?

I would try Larry Sidmore. Another choice would be a brake shop in any large city. I took my 1951 Dodge brakes to a shop in Wichita expecting to have them relined. They just swapped them for a set they had on the shelf.

[DanTreace]

Older post on sources

http://www.mtfca.com/discus/messages/80 ... 1245984575

[Craig Leach]

This seems to come up alot. I have been told by the gentalman the makes RM's that the mounting casting is differant between the 9-25 & the 26-27 brakes. The wheel mounting not fitting also comes up. I have thrown this out there before can you have a 1 3/4" x 3/8 flat iron roled at the local fab shop, welded, heated, srunk on the 26-27 drum.Then turned to the same size as the 9-25 drum and solve both issues at the same time. This would also make a more robust drum for both the park brake & the RM. Or cut the center out of the 9-25 drums & weld them to the 26-27 drums. could be cheeper than a hole new set. Just a thought?
Craig.

[rofirestone]

Or you could sell them and buy AC brakes, which work backing up as well as forward. If I remember correctly you are in the almost-state of Franklin. I believe that's hilly enough country to make external brakes in both directions a good idea.

That would be my choice.