All of these modifications will fit any and all A bodies, regardless of year. The 4.5" bolt pattern disc brake upgrades will also work on all pre 73 B bodies and all E bodies.
For those of you who want to keep front drums you have a couple of options. You can rebuild your 9 in drums or upgrade to 10 or even 11 inch drums. Just make sure your front drums are as big or bigger than your rear drums.
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
This would be the optimal "bolt on" drum brake system for the A body. Basically you will need to find any A body with 10 inch front drums. Everything between the ball joints would need to be swapped. You will need to replace the upper ball joint with the 10 inch brakes variety. You can upgrade the hardware as in the the 9 inch write up. Just be sure to get the 10 inch hardware and not the 9 inch hardware.
11 inch C body drums are adaptable to the A body, optional on B and E bodies. You will need to modify your control arms, uppers and lowers, to accept the C body ball joints. This is not a do it yourself kind of thing for most of us. Find a competent machine shop or race car fabrication shop. Once the ball joints are installed you can find a suitable C body donor and use everything between the ball joints, off the donor. Again, you can use the upgrades mentioned in the 9 inch section to upgrade the performance of your 11 inch drums, just be sure to get the 11 inch items, vice the 9 inch items.
I'll outline several easy upgrades to discs for all MoPars. Be careful on your choices as MoPar went from the odd 5 on 4 inch bolt pattern to the more common 5 on 4.5 inch bolt pattern at the end of the 72 model year, this applies to discs only and A bodies only.
This disc brake setup has the 5 on 4 inch bolt pattern. All of you out who wish to keep this pattern listen up. Basically, you will need to find a 72 or earlier A body donor with factory discs. Again, everything between the ball joints will need to be swapped. That's it, this is good for those of you who wish to keep the 5 on 4 inch pattern. The down side is that there are very few aftermarket rims out there to fit this and only one company still makes them new, I forget who. The problem with this approach is the fact that these parts are real pricey if you have to replace anything, save bearings and seals. They work well and will allow you to maintain the "stock" look and your current rims.
This swap will work for all drum braked A, B, or E body vehicles.
This disc brake setup uses the more common 5 on 4.5 inch bolt pattern. This is a bolt on swap for any A, pre 73 B, or E body with front drums. You will have two options for rotor size, 10.87" and 11.75" rotors. The larger rotor requires the use of 15 inch rims minimum.
Swapping in the small rotors is extremely easy. Find any 73 and newer A or E body. Use everything between , and including, the ball joints. If the disc brake ball joints won't fit in your control arms ( a rare occurrence but does occur in some cases, not an issue on B or E bodies) the get the control arms as well, A body only here. Install above parts into your MoPar and it's done.
Since A bodies didn't come with these rotors, stock, it's slightly more involved. Basically, you will use everything from the small rotor swap except the rotors and the caliper adapters. You will need to use the bigger rotors, obviously. These rotors can be found on a horde of mid to late 70's B and C body cars. Grab the caliper adapters and calipers, if different than your current calipers, off the rotor donor. Install these in place of the smaller rotors and caliper adapters, simple, eh? You must use 15 inch rims for this swap.
There are two types of calipers you may use in this swap, sliders and pin type calipers. Either type can be used with either rotor size. The difference is in the adapters. The slider type caliper can be identified by the fact that it rides in a groove machined into the caliper adapter. The pin type can be identified by the fact that the caliper rides on a pair of pins. Some people feel the pin type is less prone to sticking. I prefer the slider type and have had no problems with sticky calipers. The key is to install them by carefully following the Factory Service Manual, get one. Do not try to use the pre 73 calipers in this swap as they won't work without serious fabrication. The pre 73 calipers are of the four piston design whereas all the post 72 calipers are of a single piston design.
There are four different caliper adapters available. They can be broken down into two groups, adapters for the slider calipers and adapters for the pin type calipers. There are two different slider adapters, one for the small rotor and one for the large rotor. There are two different pin adapters, one for the small rotor and one for the large rotor. Pay attention and get the right set. It would be wise to grab the rotors, calipers and adapters off the same donor if at all possible.
Since your life could depend on the ability of your brakes to function correctly you must be careful. Using parts "as is" out of a junkyard is asking for it. Been there done that, ONCE, and only once. Replace all hoses with new, period. Turn your rotors or drums, rebuild yourself or buy NEW, not rebuilt, calipers, wheel cylinders and master cylinders. Replacing the pads, wheel bearings and seals is another good idea. Don't be penny wise and pound foolish. One thing to keep in mind is that, while they work, organic pads are at the bottom end of the performance spectrum. Installing a set of quality semimetallic pads will improve braking performance. Fully metallic pads are a no-no on the street, they tend to perfom poorly till warmed up.
It is imperative that your front brakes be more powerful than your rear brakes. Do not install 11 inch drums in the rear if you have 9 inch drums in the front. You will find the rear of your car coming around on you in a hurry.
Pretty much the most basic brakes you'll find on an A body. Upgrades will be identical to the 9 inch front brakes section.
These will be the largest, stock, brakes found on an A body and the smallest drums found on the rear of a B or E body. These are adequate for almost all applications. Again, upgrades will be identical to the 10 inch front brakes section. Use the finned drums.
Ah, now for some upgrades. The 11 inch drum brake setup found on the bigger MoPars, B, C, E and D bodies, will bolt to the 8 1/4, 8 3/4 or 9 1/4 axle. The only problem is on the 8 3/4 with the original 5 on 4 inch bolt pattern, A body only. There are no 11 inch drums with the 4 inch bolt pattern. You either need to convert your axle to the 4.5 inch bolt pattern (preferred) or redrill the drum to the 5 on 4 inch pattern. If you already have the 4.5 inch pattern then all you will need to do is find a donor with 11" drums. You will need everything from the backing plate out. Bolt this onto your axle and your set.
There are two options for rear disc brakes. The early to mid 70's Imperials had rear disc brakes as an option. If you find one you can bolt them up to your axle easily. The Imperial rear discs used mini brake shoes, located inside the rotor hat, for the emergency brakes. It used a slider type caliper, just like the fronts, to act on the rotor. You must run the large front rotor with these brakes. The only downside is the fact that the rotors appear to be unavailable new. Your other option is aftermarket rear disc brakes. Some have an emergency brake and some don't. Get the emergency brake setup and avoid the setups that have no enviromental sealing, they are labeled "race".
Upgrading to power brakes is a little more involved. First off you need to be aware that the firewall sheetmetal went through several changes that will preclude complete interchangeability. Your safest bet is to use a donor of the same year as your MoPar. Anything else and you should make very careful measurements to insure swapability. To swap in power brakes you need everything from the pad on the pedal your foot actuates to the master cylinder. This will include any and all mounting brackets under the dash or in the engine compartment. This is not a difficult swap just kind of tedious. I prefer manual brakes for the increased feel.
There are two types of master cylinders you can use. The power brake master cylinder must be used if your running power brakes. The power brake master cylinder can be used in a manual brake application for increased pedal firmness. You must insure that the master cylinder pushrod receiver has the pushrod retainer groove machined into it. If it doesn't then you can't use that master cylinder in a manual brake application. You can use a manual master cylinder in a manual application to decrease the pedal effort. I use the power brake master cylinder in a manual brake setup for the increased firmness. It is critical that you use a disc brake master cylinder, wether power or manual, in a disc brake application. If you use a drum brake master cylinder in a disc application you will drag your pads on your rotors which will shorten the life span of the front brakes and increase you fuel consumption. Conversely, if you use a disc master cylinder on a drum application then you run the risk of fluid leakage at the wheel cylinders. This has the potential of dissolving your shoes and ruining your drums in short order.
For your safety your front brakes should always lock up before your rear brakes. If your rear brakes lock up first you could be in big trouble as your rear end will tend to come around on you. To compensate for this you could run larger bore calipers in the front, smaller bore wheel cylinders in the rear, or get an adjustable proportioning valve. The easiest, and most cost effective would be the adjustable proportioning valve. They tend to run around $40 mail order. If you convert from drums to discs use the metering valve off the disc donor car. This will ensure that your brakes, front to rear, are applied evenly.
Yes ABS is a possibility. You have two options. The rear disc brake equipped Imperials, mentioned earlier, have ABS as an option. Not all rear disc Imperials had the option so look for wheel speed sensors at all four corners to ensure the Imperial has it. If you luck into one of these donors you might want to consider buying the entire car so that you can assure yourself of getting the entire system. You will need the Factory Service Manual for the donor and getting a copy of the parts diagram for the ABS system is an excellent idea. You will need to transplant the entire Imperial braking system, from master cylinder to rotors, into your A body as well as the entire ABS system. Use the FSM and parts diagrams as a guide. Your other option, as a "bolt on" is the aftermarket ABS kit you see in JC Whitney and Summit. It might be available from other sources. It is an entirely mechanical ABS system that appears to limit maximum brake pressure spikes in the system. I believe it's a passive system as it has no wheel speed sensors and cannot accurately determine lock up. I further believe it uses a pressure set point to trigger it. I am not a degreed engineer and have not dissected the system, nor seen one outside of a catalog. So take my comments with a grain of salt. Another option is the Stewart LBS system. This is designed to work on the rear brakes only and prevents their lock up. This is the system used by the boys of Nascar so it probably works and is relatively cheap.
� 1998, 2002 Steve M. Knickerbocker