Hot rodders are known for a love of excess. When it comes to cars, they often say that you can't have too much of anything. About the closest you can get to a desire for balance is claiming that one thing which causes trouble by seeming to be excessive should be made up for by making everything else equally overdone to accommodate it. This idea appears in sayings like, "There's no such thing as too big a carburetor, only not enough engine." "There's no such thing as too much horsepower, only not enough traction." Well, if you care about stopping quickly, it seems there's no such thing as too much braking power. Period.

And really, there's no reason for this disc brake swap other than excess for its own sake. Sure, the stock 9" drum brakes on my Dodge Dart don't work very well compared to the brakes on a modern car. However, a stock set of A-body disc brakes will provide more than adequate braking by many accounts. The brakes I'm swapping in are about an inch larger than anything Dodge ever put on a Dart. The vented disc rotors are taken off a gargantuan Chrysler Newport, which weighs about a half ton more than what they're going on. These brakes are as big as what BMW used on their heavyweight M6. Not many engineers would be able to justify using these massive brakes on a car that was built to be a relatively lightweight family sedan, and fewer still "bean counters" would ever approve of such a thing. Sure, it's overkill, but when you're using junkyard parts, it's not that much more expensive than bolting on a stock disc brake setup. Maybe someone in the corporate world did have a mind to use these on a Dart, though, because the right combination of stock parts will allow these brakes to bolt on like they were designed to go there.

If you're going to take the suspension halfway apart to install a new set of brakes, why not take it completely apart? That was the logic behind rebuilding the front suspension and installing stiffer torsion bars. After all, a lot of the suspension components have worn a bit from over 30 years and nearly 200,000 miles on the road. Consequently, the Dart's getting a complete front suspension rebuild using Energy Suspension polyurethane bushings and a set of heavy duty torsion bars, along with the heavy duty brakes. The heavy duty torsion bars are likely to reduce the Dart's tendency to bottom out over bumps, in addition to further reducing body roll.

Special thanks to the staff of Mopar Action Magazine, who as far as I know was the first group to attempt this particular swap, and to the various members of the Mopar Mailing List, who provided me with valuable information on the swap and Mopar front suspensions in general.

Disc Brake Parts List

For the disc brake swap, you will need the following parts:
Disc brake rotors, wheel bearings and seals, splash shields, caliper brackets, and calipers from a .75 or later Mopar B or R body. I would suggest buying the bearings new, a rebuilt set of calipers, and get the rest from your local junk yard. When getting parts off a junkyard car, it's good policy to bring some sandwich bags and put all the nuts, bolts, bearings, small fittings, and everything else you have to remove to get the part off in the bags. In particular, be sure to grab the fittings that hold the hose to the caliper from the donor car's calipers, and the parts that hold the caliper to the bracket - they frequently aren't supplied with either hoses or calipers at the parts store. These rotors are huge, about 11.75" in diameter. Note that Chrysler single piston calipers fall into two categories, pin type and slider type. Both were used on the donor cars. They're easy to tell apart: Pin type calipers are held to the bracket with two pins that go straight through the bracket, while slider type calipers are held in place with sheet metal clips. I'll be using slider type calipers in this conversion, but in practice, the two appear to work equally well. Just be sure the brackets match the calipers, and you'll be fine. See the note on hubs in "Getting started" if you are unfamiliar with how to remove the rotor from these cars; they combine the rotor and hub into one unit. The rotor does not come off after the wheel and caliper are removed.

These rotors, calipers, and brackets can be bolted to most mid-70's or later Chrysler products for an instant brake upgrade, including Dodge Diplomats, Chrysler Fifth Avenues, Dodge Aspens, and Plymouth Volares. Unfortunately, you're going to need a bit more parts to make these work with pre-.73 A-bodies like the Dart.

Wondering what B and R bodies are? While earlier B-bodies ones included many muscle car legends, but the late 70's they'd grown into luxury land yachts. The R-body is an even larger car, built on a stretched B-body platform. They may be one of the best parts cars Chrysler ever made. If you see one in a junkyard, be sure to take a good look at it, as there are many things you can use in other Mopars. They frequently come with 400 cubic inch big blocks under the hood, or at least 360 inch smallblocks, as well as the huge front disc brakes and their famous rich Corinthian leather seats, any one of which might be useful for a project car. The cars to check out are the .75-79 Charger, Cordoba, Magnum, Fury, and Monaco (except the Royal Monaco and .75-.76 models), plus the .79-.81 St. Regis, Gran Fury, New Yorker, and Newport.

You'll also need some parts from a disc brake equipped .73-.76 A-body. These parts include all the ball joints, the upper control arms, and the spindles. The ball joints should be bought new if you can afford them, but the control arms and spindles generally don't wear out. Note that the drum brake equipped A-bodies from these years use the same upper control arm, so if for some reason you get your hands on a set of spindles without the control arms, you have a wider choice of donor cars for the control arms. The lower ball joint will attach to control arms from other years, but the bolts holding it to the spindle are different, so you cannot attach an earlier lower ball joint to the .73-.76 spindles.

If you have drum brakes, you can either get a master cylinder designed for disc brakes, or you can modify the stock cylinder, as described later. Many A-bodies you'll find in junkyards with disc brakes have a four bolt cast iron master cylinder which will bolt in directly in place of a drum brake master cylinder. If you want a lightweight, aluminum master cylinder, you can get one from a Dodge Diplomat or Chrysler Fifth Avenue from the 80's, rebuild it with a kit from NAPA or other auto parts store, and bolt it in using a Mopar Performance adapter kit. This master cylinder is almost identical to the Mopar Performance lightweight master cylinder. Whether you want to use a booster is up to you. If you took the master cylinder from a car with power brakes and don't install a booster, the pedal will feel a bit stiff. Attaching a master cylinder designed for manual brakes to a power booster can cause trouble.

The .66 and earlier A-bodies came with a single reservoir master cylinder. This is not particularly safe; I've had one fail while backing down a steep driveway and nearly wound up in the neighbor's yard. If you have one of these, replacing it with a later dual reservoir master cylinder will make your brakes much safer. The Dart shown in this article was converted to a dual reservoir master cylinder using a .68-.70 master cylinder and front brake lines taken from a .72 Dart.

You will also need brake hoses. The hoses from an Aspen or Volare will work well. These hoses come with a bracket clipped to the hose, which should be carefully removed with a screwdriver. To balance the front and rear braking power, I bought an adjustable proportioning valve from Summit.

Lastly, the stock wheels won't fit on these disc brakes. First, the brakes are often nearly as large as the stock wheels. Second, the stock A-body bolt pattern until the .73 model year was 5 lugs on a 4" bolt circle, while the discs have a 4.5" bolt circle. Luckily, this is pretty easy to find wheels for. You will need wheels that are at least 15" in diameter to clear the caliper. Converting the rear bolt pattern is beyond the scope of this article, but there are several ways to do that, including axle swaps and redrilling the stock axles.

Other Parts

Several other parts were also added to the Dart. Since taking apart the suspension is not easy, it's a good idea to add many modifications at the same time if you can afford it. The rubber parts were fairly worn out, so I opted to replace the bushings with a complete Energy Suspension kit. I also bought a used set of 0.870" torsion bars, torsion bar dust boots from Year One, and new tie rods. If you've seen A-body tie rod ends in a catalog, you've probably wondered why the later ones are considerably less expensive than earlier ones. I'm not sure why either, but they are interchangeable, so you might as well go with the less expensive ones. Those who want stiffer tie rods can use C-body tie rods, as these will work on an A-body. You'll need both the adjusting sleeve and the tie rod ends if you want to try this swap.

Special Tools

Sure, it would be useful to have a full set of air tools and a lift to do this swap, but I don't have either. However, there are some special tools beyond the usual wrenches, screwdrivers, and jackstands which you'll need for this swap. Perhaps the most useful is a pickle fork, a large two pronged tool resembling a cross between the serving utensil and a crowbar. A one piece forged pickle fork is stronger than one made in two pieces and welded together. While it's possible to install the proportioning valve under the car without special tools, it's much more convenient to have it next to the master cylinder for easy adjustment. To put it there, you're going to need a double flare tool to modify brake lines. Some people also like to have tubing benders; I prefer using a big socket or piece of pipe to form bends in brake lines. Lastly, once you get the suspension together, you'll need to lubricate it with a grease gun.

Getting Started

The first step is to get the car up on jackstands and remove the front wheels. The factory service manual recommends popping the wheel covers off, then removing the grease cap from the brake drum and disassembling the castellated nut assembly so you can remove the drum and wheel as a unit. I prefer to remove the wheel first and then take off the drum. Remember, Chrysler front brakes have integral hubs; the drum does not come off on its own once the wheel is removed. To get the drum off, you must remove the center cap, then find the cotter pin in the grease blob underneath and pull the cotter pin out. After that, you can remove the nut holding the wheel bearings in place, and slide the brake drum off the spindle.

The first thing to do once the car is off the ground with the wheels and drums off is to unload the torsion bar. This is done by turning a bolt in the lower control arm (see illustration) until the crank assembly on the lower control arm begins to retract into the control arm. Be sure to take note of the position of the adjusting bolt before you start, so as to make it easier to get the car to a reasonable ride height once you're done.

Once you have unloaded the torsion bar, it's time to separate the upper ball joint from the spindle. After removing the cotter pin and nut from the ball joint, there are several ways to press the spindle off the ball joint. The manual says to use a screw device specially made for the purpose, but not too many people have those. An air chisel with a ball joint separating attachment is also a nice thing to have, but I didn't have one of these, either. So, I just used a standard pickle fork and some brute force. It's possible that driving in a pickle fork far enough, in the manner shown in the illustration, will do the trick. However, after 30 years or more on the road, the ball joint can sometimes almost freeze to the spindle. I've found that the most effective to use a pickle fork to separate especially stubborn ball joints is to pound it in with a sledgehammer at such an angle that the handle of the pickle fork is sticking straight out from the side of the car, then standing on the pickle fork! It's probably not the safest way to try this, but it works.

With the upper ball joint out of the way, removing the upper control arm is relatively easy. You'll need the right combination of wrenches to get around the shock absorber, but it is simply held in place by two bolts. Once the bolts are unbolted, it may take a little wiggling or even prying to remove the control arm.

You do not need to remove the lower ball joint to remove the spindle, and removing the spindle makes removing the lower ball joint a lot easier. On drum brake equipped cars, four bolts hold the drum backing plate to the spindle, and the lower two of these also attach the spindle to the lower ball joint. These bolts do simply unbolt, but they're likely to take a lot of force to do it. They were tightened tightly at the factory, and slightly rusty threads make it even worse. Don't forget to remove the brake hose. You'll need to get the bolts completely out before the spindle comes off, although the backing plate will come off easily once the nuts are removed.

Now, it is time to separate the tie rod ends. If you intend to reuse your tie rods, you will need to remove the outer tie rod end from the lower ball joint. You'll probably want to replace the dust boot even if you're keeping the tie rod end if you're using a pickle fork. If you're replacing them, remove the inner tie rod end from the center link. Luckily, tie rod ends are a lot easier to separate than ball joints, although the technique is pretty much the same. The biggest difference is that driving the pickle fork in with a hammer is nearly always sufficient to separate them. Once you have the tie rod end removed, separate the lower ball joint from the spindle the same way you separated the upper one.

If all you want is the disc brakes, you can stop disassembling things at this point. The disc brakes can be installed with the car disassembled this far. However, if you want a full suspension rebuild, you'll want to remove the lower control arm, torsion bar, and strut rod.

Disassembling the Lower Control Arm

Removing the lower control arm is mostly straightforward, except for the occasional stuck nut on the strut rod and the pressed in torsion bars. First, unbolt the shock absorber and the sway bar (if present) from the lower control arm. The strut rod will also just unbolt, but sometimes it may be difficult to get off. I'm not sure how they managed to get the one piece strut rod bushings into the K-member, but I found the easiest way to remove them was using a utility knife. Fortunately, the replacement bushings from Energy Suspension are a two piece design which you will find much easier to install.

Now, it is time to remove the torsion bar. They are pressed in and not easily removed. First, you will need to remove a retaining ring in the back of the torsion bar. Next, you will need to come up with a way to apply force to the bar. I found the simplest way was to stick the pickle fork between the K-member and the lower control arm, place a length of pipe over the pickle fork handle, and pry the lower control arm off the shaft attached to the K-member. With enough prying, eventually either the torsion bar will drop out of the lower control arm, or the lower control arm comes off the shaft with the torsion bar still attached. In the latter case, it should be possible to hammer the lower control arm off the torsion bar. It is possible to unbolt the shaft from the K-member, should you wish to remove the torsion bar from the lower control arm without removing the lower control arm from the shaft.

Bushings and Seals

After disassembling the suspension, it's a good idea to replace the bushings. Except for the strut rod bushing, this will require a press. I simply took the control arms to be installed and the rotors to the local machine shop to have the bushings and bearing seals pressed in, and the upper ball joints installed (which requires a very expensive square socket if you wish to try at home). Just make sure that the machinist knows the ball joints screw in. The upper ball joints do not press into the upper control arm, and attempting to install them in this manner will damage both the ball joints and the control arm.

Reassembly

Putting the suspension back together is fairly simple compared with disassembling it, unless you get the torsion bar stuck partway in. It pays to remove any rust on the hex ends of the torsion bars with a wire brush wheel, especially if you're upgrading to a set of used heavy duty torsion bars. The rest of the assembly is extremely straightforward, with everything bolting up as if the factory intended for these parts to be used together. It's often to your advantage to install the spindles with the caliper bracket pointing to the rear, instead of the way they were set up from the factory with the bracket pointing to the front of the car. This will keep them out of the way of certain swaybar setups, although on the Dart this did not seem to be an issue.

Valving

You will also need to attend to some issues with the valves in the stock brake system if you do not originally have disc brakes. While a stock disc brake master cylinder will work well in this setup, you can also modify the drum brake master cylinder. This modification is relatively easy - you will have to remove the residual pressure valve from the line going to the front brakes (note that this is often the rear fitting on the master cylinder). To do this, start by remove the hard line. There is a conical brass fitting in the master cylinder port with a small hole in it. Stick a screw into this hole, screw it in tightly, and pry the screw out. There is a ball and spring assembly behind it. Remove this assembly, if it doesn't pop out when you remove the cone, and put the cone back in place.

You will also want a proportioning valve to ensure that the brakes are applied evenly. Since they never put these brakes on an A-body from the factory, a stock proportioning valve is going to be a compromise. An aftermarket adjustable proportioning valve will solve this problem. You will want to plumb this into the line going to the rear brakes. You can install this at any point in the line, so pick a spot where you can easily reach it to adjust the brakes, such as right next to the master cylinder.

After all this is done, you'll have lost some brake fluid and accumulated some air in the lines. You'll definitely want to bleed the brakes before you drive it, and once the brakes are ready, drive it to a trusted alignment shop to have the suspension aligned correctly. Be sure to call ahead, as some shops won't touch older cars even if they do have all new suspension parts.

Stay Tuned

The brakes on the Sports Sedan are back together on one side, but problems with a stuck torsion bar prevented the rebuild from being completed at the moment. Watch for pictures of the completed installation and a road test of these brakes coming soon. And once that's over, well, there's always the brakes at the other end. Some would say that 11.75" rotors on the front alone are more than a Dart needs with any halfway decent rear brakes, but when is too much enough?