I'm thinking of installing RM brakes on my 24 T. I have a set of 26-27 drums in my shop. Can I use those for the RM setup instead of buying the drums from them? Are they the same? Do I need to buy longer hub bolts?
The 1926-27 are sized to fit the 11 inch 1926-27 drums. The RM drums supplied for the pre 1926 cars are a different size (as are the brakes) and are flat where they mount to the hub. Same cross section as original drums only larger. The 1926-27 brake drums are dished. So no unless you install a big drum rear end, drums and hubs you can't install that setup. Yes you would need the longer hub bolts if you want to keep you original brake drums for parking brakes if installing the pre 1926 type.
Side note; not sure if the hubs them self's are different for 1926-27 wood wheels.
Thanks, Mark! Kinda thought that from the way the RM large drums look! just trying to save some bucks!!
Bud Williams sell a large drum kit for the six bolt wheels.
The 26-27 hubs can be used if you have the 26-27 backing plates. Otherwise get the new larger drums and longer bolts. It is VERY important with rocky mountain brakes to have good parking brakes and also a good transmission brake. The Rocky Mountain brakes work very well when going forward, but if you should happen to stall going uphill, you need good parking brake and/or transmission brake to hold the car when rolling backward.
If you purchase the 26-7 RM brakes the mounting of the springs to hold the lining off the drum is a little different than the earlier brakes. Not impossible to solve, but just something else to fix.
It boggles my mind that one would design a brake to replace a transmission brake yet require that that same transmission brake be a backup for the new brake.
I never thought that the RM brakes were designed to replace the transmission brake. I thought they were designed to supplement the transmission brake. I always set mine up so that they both work with the transmission brake kicking in with additional pressure on the pedal so that the RM brake does most, if not all, of the stopping but the transmission brake is there for added stopping power going forward and as the primary braking source in reverse.
I agree with Val, the two systems work best in conjunction with each other. It took me a lot of fiddling and adjusting between the drum band and the brake bands to find that sweet spot when most of the braking was on the rears, and only on the brake drum when pushed hard to the floor. It definitely takes some patience, but in the end, very well worth the time and effort.
If you don't use the equalizer that they sell there are easier ways to do the brakes to use both systems.
Someday I will post photos of the version I made.
After watching a young lady spiraling downhill backwards after stopping on an incline because her RM brakes don't work in reverse, I would not put them on my car. Not everyone realizes what a hazard this can be.
I've heard many times that RM brakes don't work in reverse, and if you install them you will not be able to hold the car still on a back-incline. I've never had any trouble of this type with my RM brakes. However, I never had this trouble before I installed the auxiliary system.
RM brakes do not take the place of the factory brake; they add to the braking effect, and the effect is quite noticeable if, like me, you have to drive your antique in modern, heavy traffic. The ability to come to a complete stop in similar distance to a current machine having ABS 4-wheel discs is important. My 27 tudor came from the factory with brakes designed for a 1908 gas-buggy encountering no oncoming traffic. By 1927, everything had changed, including driving speed and traffic, and the transmission brake was, in my opinion, inadequate.
If your RM brake does not work downhill backwards, then it is improperly adjusted. With the new RM braking system, my 27 T is much safer to drive than my 29 Model A. With the Model A, I have about 3 panic stops before the brakes start to overheat and fade, and in Atlanta traffic, every stop is a panic. The RM improves upon over-heating, while the Model A, with internal expanding brakes, degrades.
Be careful out there, and install a set of new RM brakes.
This subject is always interesting to me. I believe I have learned that different manufacturers of T auxiliary brakes approached the problem differently. A perfect example of this is the idea that RM brakes were intended to be used with the transmission brake, which may be true. In contrast Bennetts clearly were not. They came with their own Bennett brake pedal which replaced the T pedal. It did not have the transmission brake cam, so by definition the transmission brake was not used at all with the Bennetts.
I think at the end of the day the best T brake advice is the old advice that you should drive your T as though it has no brakes at all. This way you will never be disappointed.
The best way to stop a T is to stop applying gas ahead of time.
The problem I have seen is that the brakes were not properly adjusted. It is simple to take the clevis pin out of the link between the pedal and the equalizer and adjust the transmission brake so that the pedal is about 1 inch above the floorboard when you stop the car.
The way I adjust the Rocky Mountain brakes is to adjust the parking brake first. Do this in the usual manner. Then adjust the bands on the rear wheels to 20 thousandth clearance from the drums. Next adjust the rods between the Rock Mountain Brakes and the equalizer so that if you pull the parking brake back one more notch the Rocky's are tight. In other words the parking brake comes on first and then the Rocky's
Lastly adjust the link between the pedal and the equalizer so that the Rocky Mountain brake is tight at 1 1/2 inch above the floorboard. Put the pin in place. Test the brakes both forward and backward. You should easily be able to slide the wheels when moving backward by pulling the parking brake lever hard. Then the foot brake should slide the rear wheels if you push hard.
It is a BIG mistake to leave out the parking brake shoes or the transmission band. That is when you can't stop going backward.