BTFD 3227

I have noticed that even with the electronic ignitions my 707B runs better on both. A runs pretty smooth. B runs rough and back fires. Probably a timing issue. I’ll get to that as soon as I get the brakes sorted and ready for actual road testing.

Maybe someone has tinkered with this and knows….. Are spoke hubs different sizes for different trucks? Mack vs Ford, International, Chevrolet? Or are the spoke hubs interchangeable?

I was afraid to ask the price for 16 after he quoted me the price for the next closest drum he had available. $1,195.00

Another dead end on the aftermarket brake drums. Durabrake pretty much said they were the last to make them still in business and haven’t made them in 25 years. Need a minimum order of 16 to make a run. Unless I find a set of nos lying around, it’s out to the junk piles with a measuring tape for me. Anybody got a list of older trucks that would have used 15" brakes on the mid 50’s? I’m guessing Ford, Chevy, International and of course Mack. Any others?

Yes, the dual system is for efficiency as well as a safety backup system. If one system fails while pumping a fire, the other system keeps things going.

Doing both of my distributors was a bit but not having to deal with points ever again made it worth it to me.

Are you just needing the points and condenser numbers or the electric ignition parts? I just swapped the ignitions over in our 707b. I’m guessing they’d be the same. I’ve got new points and condensers that came with the truck but swapped anyway.

This project is for the Firefighters Union outreach program so I’m on a fairly tight leash when it comes to modifications. Budget is pretty tight as well. Full rear end swaps is out of the equation. I agree that that would end up being a bigger hassle. The drums are the only thing that’s holding this project up. I’ve got shoes to be relined, cylinders will be rebuilt and have already obtained all new bearings and seals. Hopefully I can find a set new laying around or a good set in one of the repair/rebuild shops around here. I speak for the union when I say,,, we really appreciate the information and assistance from this page and its members. Thanks guys and keep up the good work in keeping these old classics rolling down the road.

Paul, I didn’t really think of doing that. If I understand you correctly, I find a drum that’s 15x6 and matches all the other specs but is 1.16" more overall depth, that extra 1.16" can be machined off without affecting the drum function? Didn’t think of doing it that way. Makes sense though. There are a couple drums showing available but limited that match but are more overall depth. Most was about 1.36" over. I need 7" overall depth. Joseph, I wish it was that easy! Can’t hardly find anybody that wants to work that hard anymore. Geoff, The specs I’ve got are: Pilot of 11" with a stud dia of 12.5" I’ve found a couple drums that are close as I mentioned up top. Hopefully still available or at a salvage yard close by.

Looking for rear brake drums for a 1955 Mack B85F with hydraulic brakes. Specs: Pilot: 11" stud dia: 12.5" 15x5 brakes. 15x6 will work.

No luck on aftermarket drums. Gunite went out of the drum business and Webb wheels doesn’t have anything that match these specs. Back to square one. Surely someone out there has a couple drums, knows where some might be or knows of a solution to get this old girl back out on the road. Without rear brakes this project is pretty much done for.

Thanks guys. Makes sense. I appreciate the information. Hopefully I can find drums now and get this old girl back on the road soon.

Getting ready to start rebuilding the rear hubs on our B85 and have a couple questions. First, are both bearings oil bath or is the outer oil bath and inner greased? Second, if both are oil bath, what’s the purpose of the inside seal between bearings and how does oil get back to the inner bearing? When I disassembled there appeared to be grease residue on both bearings. Sludge. Looking for guidance from the masters.

Thanks Geoff Aftermarket seems like it may be my best option. I’ve talked to a couple of individuals up north that may or may not have drums laying around somewhere in their collection. The stamped steel piece you mentioned, is it separate from the drum and hub? How does it attach? Just wondering if something like that would solve my concern in case a seal fails. I need to figure out if it’s even needed.

Yeah, I’m finding out that the hydraulic brakes on these older Mack’s are rare and rather unique. Especially the rear brakes. I’ve got a casting number off of the good drum but nothing crosses over. The rear shoes are 15x5 and are rare as well. I’m wondering if I source a set of drums without the concaved bowl, which I’m guessing is by design in case of a seal failure to stop oil from entering the drums, will there be any issues. Unless there’s a seal failure. which brings me to another question,,, is the inner bearing a grease bearing or oil bath? If it’s oil bath like the outer, then why is there a seal in the middle of the hub? Another topic for another day I guess.

Greetings all and thanks for letting me in. New here but have been reading along as a guest for a while but can’t find the information I’m in need of. I’m working on a 55 B85F for our local Firefighters Union and need some help locating rear hydraulic brake drums. At some point the rear brakes have gotten really hot and the pass rear drum broke. The driver side is intact and can hopefully be turned out. Does anyone out there have or know of a source for these drums? Or an aftermarket alternative. I just need to find drums to get this old girl stopping again. Any help would be appreciated.