9 inch drums, A body only
If you insist on running 9 inch drums here the ticket for optimizing them as told by Slant Six Dan
Ah, yes, the joys of the A-body single-master-cylinder 9" drum brake system. NOT! First off--asbestos does NOT CAUSE BIRTH DEFECTS!!! It can cause Asbestosis, a form of lung cancer, but it's turning out that you need heavy and/or long-term exposure to it to have a major risk increase. Also, although you really don't want to breathe the dust if avoidable, the dust is NOT THE SAME as asbestos fibres. The fibres have been ground up into dust. Since the nasty aspect of asbestos fibres is that they are hook-shaped (like the burrs your dog brings in from the fields) and thus they catch on your lung tissue. The dust doesn't do this. So quit worrying so much. Now then, your brakes. I have enough experience with the early 9" system to know that halfway measures are rarely satisfactory--do the whole job, and do a first-class job, and you will be rewarded by NOT having to shop for a front clip whilst your face is still bandaged up!!! First off: replace the master cylinder or send it to a place like White Post restorations to be sleeved. Or, here's a better option. Replace it with the '67 and later dual master cylinder. This isn't that hard, and I have a photo article from the Slant-6 news telling how. I'd be glad to mail you a photocopy. (Coincidentally, this is the same issue that features the Canadian Valiants.) Moving on down the line, your wheel cylinders are probably rotted. Replace them. (If they aren't that bad, you can rebuild them, but the replacements aren't all that much--I think I paid $28 for a set of two front ones at NAPA. Lifetime guarantee :)) Next, replace the shoes. Use Raybestos shoes, they're the best. Now, here's the tricky part. Replace all the hardware. You will be changing from the godawful '62-'68 self adjustor to the reliable (if more complex) '69 and later style. Go to a MoPar dealer and get the brake hardware kits for an '86-'87 Dodge Dakota pickup with 9" rear drums. All the springs, cable, etc. will fit the "A" brakes. And the springs are all heavy duty, with a great 3rd generation shoe hold-down which WON'T stretch and distort like the others. You'll need to separately order four of the thin coiled springs that go directly above the adjustor star-wheel in that Dakota pickup, too. (Sorry, I don't have Part Numbers.) Next, go to a parts store, (NAPA, CarQuest, etc. etc.) and buy self-adjustor kits for a '69-'73 Dart with 9" drums. You'll need two left and two right kits. Check the drums carefully. If they're scored, etc. have them turned on a lathe, but make certain the lathe operator runs the cutter feed SLOWLY so as not to leave spiral marks. (Check to ensure the drums are still within acceptable size range before you turn them. 9.060 is the max on all rear drums and front drums up to '69. '70 and later got much better, heavy, FINNED front drums which can go up to 9.090 and will swap right on to the early brakes for added heat resistance.) The only thing to watch for on the finned drums is that if you get them off a '70, you'll keep your left-side=left-hand-thread, while '71 and later will have RH thread on the LH and RH front drums. No biggie. Make sure and use a little brake grease (LubriPlate sells it) on the backing plates where the shoes contact.) I don't advise using silicone (DoT 5) type fluid--it's compressible (no flames please) because it traps air readily. Do use a premium quality DoT 4 fluid (I don't know if you have the same rating system up there in Canada.) such as Castrol LMA formula. Sounds like you have a whole winter season in which to do this work. Putting the adjustors together is kind of a pain, but these '69 and later adjustors are GREAT!!! you set them once and forget them, they won't over adjust or rust-up like the early ones. This applies to all of you with 10" and 11" drums too. Get the '69 and later adjustors when you build the brakes. A Haynes manual for the '67-'76 Dart/Valiant will help with the adjustor assembly work. My brakes were much much much better on my '65 Canadian Valiant. Which must be why I recently went to power discs up front. . .SCREEEEEEEE! (Actually, it was because I had swapped in an 8 3/4 w/ 10" drums, and w/ the 9"s in front, the back end would swing around if prodded hard. My mother is now using that car as a daily driver while I'm in school pedaling my 3-speed Raleigh, and I kinda wanted to keep her AND my car safe in Colorado's slippery winter roads. When I get the car back--OUT GOES THAT ^&*(%^&*$ POWER BOOSTER!!!!!!!! SL6
