Because it was dark (and late) and we weren't paying attention...lol

 

Contrary to apparent popular belief, it is not uncommon for drums (or rotors for that matter) to warp when they get hot, resulting in your exact symptoms. Maybe its due to a non-uniformity in the thickness of the drum (or rotor) in some places, maybe its due to un-even heating of the drum / rotor (a slight warp when cold that is not noticeable in the braking behavior results in hot spots that aggravate the warp when hot and causes noticeable vibration when stopping). I believe if any brake system gets hot enough you'll feel vibration when stopping. About every car I've owned exhibits this behavior to some extent. My '07 300C seems to be very sensitive to this, our '13 SRX was surprisingly immune. One thing is for sure, drums / rotors that are warped cold never get rounder / flatter when hot.

I assume that after you resolved the brake assembly issue, that you loosened the adjuster star-wheel enough to stop the shoes from dragging and allowed it to self-adjust?

 

So how did the other side have both long ones?

 

Simple..like I said, it was dark and we weren't paying attention, and when I replaced the driver side shoes, I completely overlooked that they were both the same.

 

[QUOTE=JohnnyBs68S;1625353]Contrary to apparent popular belief, it is not uncommon for drums (or rotors for that matter) to warp when they get hot, resulting in your exact symptoms. Maybe its due to a non-uniformity in the thickness of the drum (or rotor) in some places, maybe its due to un-even heating of the drum / rotor (a slight warp when cold that is not noticeable in the braking behavior results in hot spots that aggravate the warp when hot and causes noticeable vibration when stopping). I believe if any brake system gets hot enough you'll feel vibration when stopping. About every car I've owned exhibits this behavior to some extent. My '07 300C seems to be very sensitive to this, our '13 SRX was surprisingly immune. One thing is for sure, drums / rotors that are warped cold never get rounder / flatter when hot.

I assume that after you resolved the brake assembly issue, that you loosened the adjuster star-wheel enough to stop the shoes from dragging and allowed it to self-adjust?[/QUOTE]
You are correct.

 

Dave - Before you hit the Magic Button & pay for a set of rear brakes shoes, be sure you're purchasing the correct set for your car. I'll look a little further (for you) but you need to perform a deeper dive into ensuring these are the correct brakes shoes. RockAuto says they're for a rear sedan 4-door (on their website), but RA is often the least accurate website to get the Part Numbers correct. Maybe they're correct, maybe not. You get two pieces of information from RA as depicted in the two images below from RA. If you "click" on the actual Part Number 17242R you'll get a different drop-down menu which states they fit your 1972 beastly U-Code Cutlass Supreme. However, I'll note (that's why you might do a little more research) on another site it demonstrates 17242R does not fit your 1972 Cutlass Supreme. I'm not 100% why you need ACDelco Gold brake shoes. Many good manufacturers of brake shoes out there on the market. When you found the rubble/bricks/fragments inside the passenger wheel drum what/where were the fragments from - did the brake shoe grenade in there or what?



This is what RA states.

Click on the actual Part No. and you get a completely different fitment.

 

I found two other websites which say that ACDelco No. fits and two which say it doesn't. Do your own research, order both sets as Jaunty suggested. I am soooooo.....tired of reading the horrendous amount of gobbledy gook sales banter on automotive supply websites. Ugh.

O'Reilly says they fit:

Cutlass Supreme Base with engine V8 - 7.5L 7456cc 455ci GAS 4BBL vin U - 2 valve OHV

1972 ,1973 ,1974
3 vehicles

 

Didn't grenade Norm, just pieces that came off the lining, enough to warrant replacement.

 

Gotcha. No "...Jimmy Carter for President” pin-on button"?

 

Norm, here's what I've got in my shopping cart from RA if I have to do the complete job. But first, I'm going to check my drums for runout to see if they're warped. If not, I'm just going to replace the shoes and hardware. If they are warped, then I'll do the complete job. RA sent me a 5% discount code, so I'll see what I end up with. I looked into O Reillys turning the drums, but they quoted me $25 each, so for that price, I may as well bite the bullet and buy new ones

 

Ha ha..nope

 

RA Discount Code:

Code: 297872754263419282
Your code expires on May 9, 2025, 12:00 Midnight CT

Rock Auto Discount Code

 

 

Ha! I got you beat Norm...mine expires on May 16th

 

Is it 5% off?

 

Probably, but if you click "My Account" I believe it will give you a specific discount code specific to your account - I think. I think they phish your My Account activity to determine how much candy you've spent w/ them, then they generate a specific discount for your "My Account" - I think that's how it works.

 

Their shipping has gotten so outrageous I haven't purchased anything from them for a long time unless it's a LARGE order, such as when I replaced AC compressor, drier, ALT, PS Pump, Serpentine Belts, pulleys, etc. on my F250 diesel tractor which made it worthwhile to pay their shipping rate for one large order.

EDIT: I generally find the part numbers I need then shop the part numbers on Amazon & eBay. Since I'm Prime Amazon I pay no shipping.

 

I took your advice Norm and Amazon is actually 10 bucks cheaper. Thanks for the advice!
On another note, what are the items I have circled in this pic? I dont remember seeing these when I worked on my brakes.

 

Those go on the parking brake side for the pin retainers.

 

Are you able to provide a pic please or reference from the CSM/ASM?

 

If I find that my drums aren't warped, what do I do from there? Let the shoes "wear in?"

 

Unless I'm wrong, I think my drums are warped. I took some pics of my initial findings, and here's what I found. As you can see, there are some spots where it looks like the shoes hitting on the drum, and some spots where it doesn't. Also, I'm getting about a .010" difference on the driver side when I rotate the drum 180 deg.
Here is the driver side:








Passenger side indicated about .018" difference on a 180 deg rotation.








Maximum runout should be no more than .002", so Im going to scoop a new set of drums today and run the same test to see what happens. I'll report my findings tomorrow.

 

I'd say get those cut but it looks like they are way past the minimum thickness.

 

I dunno and I have no way to measure them, but either way, I’m getting a new set.

 

I'm the same way. I've sold my soul to both Amazon and Google. With car parts, I'll usually find the part number for a particular brand at Rockauto and then go to Amazon and see if they have it cheaper. They usually have it at least at the same price, and, with Prime, no shipping cost as you point out (already paid for prime), and, often, it's next day or two day delivery. Can't beat that. Like I said, I've sold my soul. (It wasn't worth much, anyway.)

 

Best idea possible. Don't mess around. New drums for your car are readily available and not that much money. When I the redid the rear brakes on all three of my cars ('73, '77, '78), I replaced the drums as well, no questions asked.

With a '67 Delta 88 I once owned, new drums were not available, so I had the ones on the car turned. Worked out OK.


I have to say that you do have more tools than Carter's has liver pills, as my grandmother would have said.

 

If you're referring to the dial indicator, that's a "leftover" from my former occupation as an inside machinist. I only wish I had a set of 12" deep jaw dial calipers so I could measure the inside diameter of my drums

 

Whats an "Inside Machinist" ?

 

I ran lathes, milling machines and drill presses.

 

So after an 11am to 10pm shift at work, I grabbed a quick bite and got back to it. Put the new driver side drum on and checked the runout. I got about. 003". Much better! Tomorrow I'll check the passenger side and button everything back up. Question though...should I paint my new drums or just leave them as is? I don't want them "'rusting up."

 

I'm back at it bright and early this morning, and noticed one of my new drums doesn't have a "counterweight", and the new ones aren't as wide. Is this an issue? A prompt response would be appreciated.

 

Likely/Hopefully/Evidently the drum w/ no weight did not require a weight as it met manufacturing standards/tolerances & does not require a weight (may have been machine balanced). The opposite for the drum w/ a weight. Not all brake drums have counterbalancing weights; yet you ask a great question which is unlikely to get a definitive answer unless you take the drums to a brake shop & check balance of each. Probably a good idea in case you have to return them you have evidence. Good Luck!

 

Thanks Norm. What's your thoughts on the new ones not being as wide as the old ones? Aftermarket design change? And should I paint the new ones?

 

Those are the wrong drums! The new one is narrower than the old one. Is it possible the rear diff housing has been replaced on your car?

 

Don't know what to say regarding old drums wider than new ones - probably design change but I'm certainly no brake drum designer. I've never painted the outside of brake drums - some do. I find no reason to paint them.
Use anti-seize on h/w reassembly.

 

Yikes. Dave's image was uploaded after I read his questions & responded. They look like the incorrect brake drums.

 

Nope..it's the original, and I've already test fitted the new ones and they're good.

 

As long as the lip of the backing plate fits in the groove of the brake drum, and the braking surface is wide enough to fit the new brake shoes, it will work. But you are giving up a bit of extra width of the cooling surface from the old drums. This shouldn't be a problem as long as you don't use the car for autocross or slalom racing. 🤭 Your brakes will heat up quicker during spirited driving but for normal hotrodding, you should be fine.

 

As far as painting, any kind of gloss paint will reduce the heat dissipation properties of the brake drums. I think Eastwood sells a natural cast iron color so they would look natural but not rust. Maybe it is available in satin or flat finish.

 

I've got both of them on and when I spun them I didn't feel any binding or hear any rubbing (in reference to the lip of the backing plate and the groove in the new drums.)