Rocky Mountain Brakes - shim thickness

[bdtutton]

I am installing Rocky Mountain Brakes on my 1914 Model T and even with .004 shims there is still a little bit of rubbing going on within the parking brake drum when I apply a side load to the tires. When I have the car on jack stands and spin the tires there are no noises, but when I push really hard against the tire while turning it I think I can hear the parking brake shoes slightly rubbing against the drum. I filed the head of the bolt that holds the brakes and I filed the bolts that hold the brake drums.
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The instructions say interference will happen because you are adding the thickness of the second drum that is needed for Rocky Mountain brakes on early cars with small drums. They say modifications and shims may be required. So I expected this.
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Here are my questions....
1. Should I need more than just a .004 shim?
2. I filed the bolt head that holds the brake shoes per instructions, but I think the shoes may be rubbing...should I file them?
3. Have other people struggled with this?
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Thank you....Bryan

[speedytinc]

The parking brake pivot bolt is WAY to thick. Compare it to the original. recently completed a rux kit for a guy. Axles .090" longer. He had tried to install R/M brakes & new parking brake shoes on the stock axle before I got it. Locked the rear end .
I reinstalled the rockey's & parking shoes. Even with the axles stretches there was rubbing. I chased em down. New parking brake shoes were too wide.(Took off up to .030") Wheel bolts too long. (one was twanging the shoe spring) Finally That pivot bolt head.(head is twice the thickness of the original)
No shims used! All my trouble was in the new parking brakes.

Suggest you remove the parking brake shoes. Check for rubbing. Leave the key out.
It helped to paint the inside of the drum with some flat black rattle can. Add shims if you must.
(I hate using shims. Its a 1/2 a$$ed patch. IMO)
Then work on the parking shoe clearance.

[Scott_Conger]

with the addition of a second brake drum, you just moved the ford drum inboard (working from memory here...) by at least .125". Get out your trig calculator and you'll find that a .004" shim does not push the assembly back out to where it was pre-Rocky install. Until your Ford drum is JUST even with the OUTER face of the backing plate will you have installed the wheel where Ford did. Note: your parking brake drum IS NOT SUPPOSED TO GO OVER THE BACKING PLATE if all things are back to "new" dimensions.

Worn hubs, worn axles, rubbing with new Rockies...welcome to the club.

[Dan McEachern]

That's what was so nice about the cast iron brake drums that Jack Sutherland supplied with the original repro Rocky Mountains- no double drum flanges to deal with. Doubling up the brake drum thickness just adds a multitude of problems to the job. Probably not politically correct, but I simply removed the small brake drum and shoes. Been about 25 years ago and close to 60,000 miles ago and no issues. The small drums and shoes really don't add much to the mix.

[bdtutton]

Thank you for the responses. I have been grinding away at everything and things are just barely clearing if I use a 0.004 shim. I can force a little rubbing if I side load the wheel. I think I am going to spray just a little paint on things inside of the parking brake area and drive it a little. It will be obvious what is rubbing when I take the wheel off again. Unfortunately, the drum of the parking brake goes over the backing plate so I know the new Rocky Mountain drums have spaced the original parking brake drum way too far in.
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I am planning to add a Ruckstell rear end onto the car within a year and hopefully the axles will be a little bit longer than the stock axles I am running now. There are several issues related to Rocky Mountain brakes, but I believe it will be worth the trouble when I have to lean hard on the brakes one day in the future.

[Scott_Conger]

Quit
Grinding
Things

Lang's sells a couple different shim thicknesses and by using one or two of the thicker ones, things will work and fit just fine

[Allan]

Which parking brake shoes do you have? The ones that come in two pieces and require much tweaking to get operational, or the one piece
variety which are much better made
The only things being ground should be ill fitting reproduction parts.

Allan from down under.