Brake drums and discs often have their servicable limit stamped into them. Gots me some 45 fin buick drums and they have probably got a fair amount of meat on em but I cannot read what is stamped into them. Considering Their age and possible milage I'm sure these are probably fairly represen***ive of what most folks come up with. Anybody out there know what these measured new? The I.D. of the steel insert on both is 12 1/16"all the way around. The thickness of one of the steel liners is 3/8" all around. The other starts there but gets thinner. Somebody please clue my green *** in.
I run the buick drums and I just cleaned em up and they work just fine lots of meat how much I dont know. My car is 2400 lbs and stoping is no problem. They are not covers John
Yeah, I know that many folks have actualy used these brakes for years on roadsters and the like. Just curious to learn what these measured when they were new and how thin is too thin? Modernbeat has a killer post in the tech section that is worth the read. I'm gonna bolt these fukers up and see what they do. Anyone else?
I have installed more than a few sets. If the steel liner gets to thin you will see small holes in the the part where the shoe rides. I have a set at the shop that are good I can measure them. Scott 916-338-4327
i do believe that they are .090 over the original spec. so a 12" drum would be 12.090 max. the max machine is a little less.
I vaguely remember something to the effect of having to completely turn out the old one, seems like the rest was like sleeving it. Thats how they're made anyways. The question is where the hell would you get the liner - machine it from some other drum?
Non of my books go back that far. Most modern drums have a .060 max over the original size. Several of the older and bigger drums had a max. of .090. Personally, I think .090 is fine for a light car. Thin drums won't crack or fall apart. One of the concerns is brake fade. When the drums get too thin there is less metal to absorb the heat. The shoes over heat and they start to fade sooner. Brake fade is a natural occurance on drum brakes that is made worse with thin drums. One of the big plusses with disc brakes is they take a lot more abuse before they start to fade. Back in the dark ages before disc brakes you were taught to NOT ride the brakes on long grades. Leaving some time for the shoes to cool. That's why trucks are told to use lower gears on long grades. If you know about the potential problem and drive accordingly, you won't have a problem. Remember the whole idea of the fins was to cool the drums on those big Buick barges.
Yeah, I wonderd about this also. There is a place here in town that specializes in re-lining brakes and clutches. I'll give em a call and see what they know.
If any place can do it, Austin Brake and Clutch can. They are about 5 blocks from my house. If you need, you can drop them off with me and I can drop them off, if your work hours wont allow you to get there before closing.
Again, something I researched once for a story. In '58, the first year for the drums, the steel linders had small dimples in the brake surface. they were uniformly spaced. Only year. (Those may be the small holes mentioned earlier?) I found one drum that had "Max Dia. 12.01" cast in raised letters on the inside of the face of the drum, next to the hub. It was on a later 90-fin drum. That's what the factory said, BUT, that doesn't leave any room for turning! My personal opinion is that the factory could have wanted to sell replacement drums. One thing I have heard is that if you turn them too much, you have a problem with the shoes running out of travel to contact the drums. According to a post on the Buick Club of America's sight, a guy there had heard of thicker shoes being produced to cure that. Don't know, never saw any. But, if you were going to have a set of drums relined, it'd be easy to have them put thicker linings on, right? The way these drums were created, an iron liner was made, and the outside of the liner was very rough. The liner was put in a mold, and the aluminum was cast around it. (that took more than just a little digging to find!). I'm not saying it's impossible to resleave a drum if someone comes up with a liner, but I'd be concerned about the liner spinning inside the drum. There's a helluva lot of force there to stop a car. As for thin drums cracking, overheating and brake fading--on a cast iron drum, the liner and the drum are all the same piece. On a finned aluminium drum, the liner isn't actually a piece of the drum. The body of the drum stays the same, the liner gets thinner. (I know they're fused into one piece, but I think it would make a difference). Aluminum is about the best heat sink in the world--it will draw heat out of things, and with fins, it will transfer that heat to the air. That was the design principle behind Buick's finned aluminum drums, and they were known for their superior brakes back when the cars were new. Many magazines of the time did tests on brake fade, and raved about them. In time, they added more fins (90--double the original design) to shed more heat. My feeling is that even if the liner is thin, as long as you have good brake shoe contact, fade shouldn't be any more of an issue. I would worry about the liner becoming really thin and pealing/cracking away from the aluminum outter shell, but I think that would require really, really thin liners. Again, just my thoughts, nothing to back that up. -Brad
Here's a post from a couple of weeks ago on this very topic: AHA! This place does Buick aluminum drums specifically: http://www.oldbuickparts.com/cat610/61004.pdf Expensive, though, probably more than finding better drums? I know there are other places, too. I'd look in Hemmings Almanac, if I had one. __________________ Bruce
", seems like the rest was like sleeving it. Thats how they're made anyways. " Rustynewyorker That's interesting because when I was at the Buick complex they were being centrifugely (sp) cast. The outer drum (the finned part) was placed in a spin fixture which orientated the drum at approximately a 45 degree angle. the drum was spun and molten cast iron was poured into the spinning drum. The molten cast iron was thrown to the outside of the drum shell and allowed to cool below a molten state while still spinning. After this the drum was ejected from the spin fixture and stacked on a transport dolly where the cooling continued. After this the drums were shifted to the machining dept for final machining. After machining the drums were still so hot that they couldn't be handled without gloves. Nothing like high speed m*** production to get the job done. Another note: The molten iron was taken out a crucible with a hand ladle and manually poured into the spinning drum. The guys doing the pouring used to pride themselves in being able to ladle out the exact amount to create the liner without having too little which resulted in a s**** drum or having too much which resulted in the molten cast iron being thrown out of the drum and all over the floor creating a very hot mess. They worked in 120-140 degree temps most of the year and were some tough sonsa*****es that looked a lot like Arnold Swartzenegger. Frank
On another note. Isn't Bob Wilson (Wilson Welding) supposed to be coming out with new finned Buick drums? Frank
Yeah, but when I spoke w/ him the other day he said he still has a way to go before they are ready. He was unwilling to even guess about when they would be finished.
Aahhh Ssoooo................There it is. Any other ideas on who is re-popping these???? Bob Wilson aint done. Kanter is full of ****. ( unfreindly *******s too ) Oldbuickparts.com wants 225.00 PER DRUM to re-line!!!! I'm suprised this nich has yet to be pursued.
That is absolutely facinating! What year was this? (I'm not doubting or questioning you, I just like as much info as I can get) From Motor Trend, October 1958: "The new method of making the drums has a cast iron liner grit blasted down to pure metal, then immersed in molten aluminum at 1375* F. By slow agitation the aluminum combines chemically with the raw iron, forming a surface coating of iron aluminum alloy. The iron liner (maintained at 1375* F) is transferred quickly to a permanent mold, where the alumium drum body is cast around it." The "new method" they are talking about is the difference between when they first appeared in '58, and those on the hew '59 car they were testing. So they probably started making them one way, and then changed methods at some point. Makes sense that they'd come up with an improvement over the 12- or 13-year production span. It'd be interesting to figure out when they changed production methods. -Brad
To resleeve a drum, you would have to turn out at least most of the cast iron liner, and then turn a new one about .005 oversize on the outside. Heat the drum, chill the liner, and then drop it in. it probably wouldn't transfer heat as good as a new one, but it should work. Most truck use a steel drum, with a centrifically cast iron liner nowdays.
I have a friend who spray welded some old aluminum drums iron liners - he had to heat it up in an oven almost till the aluminum was melting then stick it into the machine to spin it as it was welded. Then it was turned on a brake lathe back to standard size. He said it was $1000 for him to do all four drums. Ouch.
Been searching for info, and this thread is as close as I’ve got, but i need a bit more clarification. I have a couple of Buick 45 fin drums, would like to use them, but need clarification on liner thickness. One drum measured internally 12 inches, the other 12 1/8. I read on another thread that internal should be 12, is 1/8th too much? Thanks
The published max ID for the 12" 45 fin Buick drum is +0.060". Having said that keep in mind the original application - big, heavy car. On a light hot rod you might be OK going a bit larger. One issue going more than +0.060" is shoe contact pattern. You'll need to contour grind the shoes to get a good fit for full length of shoe. So if you have access to an old shoe contour machine, and a light hot rod, maybe +0.090"? I've always stayed with the +0.060 and have been lucky to have a few sets that are under that. I have turned a few sets for others and used the +0.060" as a max turn to number. They were used with contoured shoes and worked fine for many miles.
Thanks Jim, that's not a lot over, about 1.5mm (I'm used to metric), so it looks like one of my drums is no use at 1/8th over, about 3mm.
You do realize that the post you answered was made November 1, 2005? He is still active on the board though. Note that the last post above yours was made Nov 12, 2018.
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