Installing Master Power Front-Disc Brakes - Gimme A Brake
Stopping Never Felt So Good
From the August, 2003 issue of Mopar Muscle
Photography by Ross Clark
One day, while out for a cruise in our red '63 Fury ragtop, someone three cars in front of us slammed on his brakes to avoid hitting a bus. We locked 'em up too-for a split-second. Then, the brake pedal went to the floor, sending us smack into the back of the minivan a few car lengths ahead. Definitely not our finest moment!
Luckily, no one was hurt, and the damage to the front of the Fury was minimal-a bent bumper and grille and a few tweaked brackets. If the same thing had happened two days earlier when we were doing 70 mph on the interstate, it might have been a fatal accident. Frankly, the factory drum brakes were marginal, even for the slower-paced world of the '60s. With today's crowded highways, people talking on cell phones, and modern cars that can stop on a dime with their four-wheel discs, most of our earlier rides can use some serious help in the brake department.
The Master Power Brakes kit...
The Master Power Brakes kit for the early B-Body includes everything shown here. Even inveterate parts scroungers like us must admit there's a certain appeal to placing an order on the phone and getting a box full of nice new parts that don't need cleaning or refurbishing. It's also easy to see why the replacement of the old rusty drums with new rotors and calipers is so satisfying from an appearance standpoint. Of course, it's the resultant stopping power and reliable operation that is the real goal here.
Time being of the essence, we chose to forgo the usual parts hunt and go with a prepackaged kit. Mind you, we have nothing against used parts. In fact, for us, a sunny day in a junkyard qualifies as time well spent. But when we saw the ad for Master Power Brakes' B-Body front-disc brake kit, we thought it would be nice to open a box of brand-new parts for once and do the job from start to finish. We decided on the manual discs, as we weren't sure whether we were going to go small- or big-block with our next engine, and clearances get really tight in that corner of the engine compartment with the added bulk of the vacuum reservoir. We placed our order, and before we knew it, UPS showed up at our door.
We took the car to our good friend Carl Solko, who has a well-equipped shop complete with a lift at his disposal. He was especially interested in this swap because he recently installed a Max Wedge in his '63 Dodge wagon and found the factory drums to be woefully inadequate for his new power levels.
After we put the car on the lift, the first order of business was to completely back off the torsion-bar tensioner bolt. The wheels, brake drums, and all of the brake lines and hoses were removed. Then, we separated the ball joints and tie-rod ends from the spindle using an air hammer with a pickle-fork attachment. The Master Power Brakes kit included spindles and caliper brackets that were bolted together and mated to the lower ball joints. We bolted the assemblies to the upper control arms. The bearings were greased by hand for maximum lubricant penetration, and the seals were installed on the rotors. The rotors were then mated to the spindles, and the rotor surfaces were cleaned with brake cleaner. It's always a good idea to clean the rotors before mounting the calipers to remove any grease or factory coatings that keep the rotors from rusting. The crusty old single drum-o'-death master cylinder was removed at this point and given the heave-ho.
Early B-Bodies had single-reservoir master cylinders, so new lines were fabricated in order to hook the dual-reservoir master cylinder to the disc calipers. The factory frame-mounted distribution block was retained, and the two ports that originally fed the front brakes were blocked with threaded plugs from NAPA-PN 131-X-3. The new dual-line master cylinder was bled on the workbench. Then, we installed the master cylinder/proportioning-valve assembly to the firewall. We were able to reuse the original brake line for the right-front brakes (see diagram) because it was already correctly positioned and had the right fitting.
There's not much good to be...
There's not much good to be said about the rusty old drum setup on the car. At the time of its introduction, the hydraulic setup was a significant improvement over the old mechanical systems. But the single-reservoir master cylinder was an accident waiting to happen. One leak or failure anywhere in the system, and you had no brakes, front or rear. In our case, a mechanical adjuster came loose on one wheel, and that was enough to make us lose our brakes completely.
Whether you're working on...
Whether you're working on a 9-second race car or a street piece, it's vital from a safety standpoint to remove tension from the torsion-bar assemblies prior to attempting any disassembly. Failure to do this can result in severe injury or even death. They are, after all, just as powerful as any coil spring, and we all know what damage they can do if they shoot out at you. The torsion bar may be somewhat subtler in appearance, but it's just as potent. Make sure to support the weight of the car with good jackstands under the framerails.
The right tool for the job...
The right tool for the job makes a difference. An air chisel fitted with a pickle-fork attachment is useful in separating the tie-rod ends and upper and lower ball joints from the original drum-brake spindles.
The spindles and new caliper...
The spindles and new caliper brackets supplied with the kit are assembled, as shown, and then mated to the lower ball joints. The resultant assemblies are then attached to the upper control arms. The original spindle nuts can be re-used, but new cotter pins are recommended.
This view from the rear of...
This view from the rear of the spindle shows the spindle/caliper bracket assembly (with lower ball joints attached) prior to being mounted to the upper control arms. The caliper (left) is also shown mounted in its installed location for reference purposes.
Sometimes, a proper installation...
Sometimes, a proper installation requires state-of-the-art equipment or cutting-edge techniques. But, more often than not, the basics make the difference. Although there are automated methods, we prefer to grease the bearings by hand. It's by no means a white-glove process, but doing it this way insures the grease penetrates completely and lubricates every bearing surface. This, in turn, helps assure reliability and long life.
So, all that was necessary was minor tweaking to connect it to the new proportioning valve under the master cylinder. A new line was bent and installed for the left-front caliper and hooked into the appropriate port on the new equalizer block. The original line that went from the single-jar master cylinder to the factory distribution block on the frame was adapted to feed the rear brakes by cutting off the original flare as close to the master cylinder as possible, slipping on the kit-supplied flare nut and reflaring the line using an Eastwood Automotive double-flare tool. New flex lines were connected to the calipers using the copper seal washers supplied (two per caliper). At this point, we connected the kit-supplied adjustable pushrod from the master cylinder to the brake pedal and adjusted it so the brake-light switch functioned properly.
Because exhaust systems tend to put out a lot of heat, the instructions recommend building a sheetmetal heat shield for the master cylinder if the exhaust manifolds or headers run too close. When we replaced the ragtop's ailing poly-headed 318-two-barrel with an '81 318-four-barrel a while back, we took the advice of friends and used '95 Dakota truck exhaust manifolds. These are really a slick deal. They fit like they were designed for an LA engine in an early B-Body, and they don't require any special heat shielding because of their virtually perfect routing.
The MP Brakes instructions specify the use of DOT4 brake fluid, even though the master cylinder provided with the kit is clearly marked "DOT3 brake fluid only." We checked, and the only difference is the DOT4's higher temperature rating. So if you're not able to get every last drop of the old fluid out of your system, at least there won't be any compatibility problems between the two. During the final brake-bleeding procedure, we noticed the left rear-wheel cylinder was leaking, so we replaced it with a new one.
With the installation basically complete, we stepped back to assess the changes. The contrast in appearance between the rusty old drums and the new rotors and calipers is dramatic, as is the dual master cylinder/proportioning valve combo compared to the old setup. More importantly, a test drive showed stopping power to be significantly better and more responsive to driver input. The vague and insecure feeling when applying the pressure to the drum brakes was replaced by a distinct impression of control. The car felt lighter and more competent overall, and the chances of experiencing a complete brake failure-as we did earlier-were reduced exponentially with the dual-line system.
Our earlier check of the suspension had indicated the ball joints and bushings were tight and in good shape, but the shock absorbers had seen better days and were replaced with a set of MonroeMatic Plus gas shocks. In addition to better suspension control, they also provided an anti-dive effect upon braking, thanks to the gas shocks' resistance to compression. With the new shocks installed and at proper ride height, the car was given a good frontend alignment and a renewed stamp of approval for summertime cruising.
Granted, it may be more fun washing and waxing our cars than busting our knuckles on the brakes, but looking good isn't much comfort when you're careening out of control. Do yourself a favor and spend some time on the brakes!
The spindle, caliper bracket,...
The spindle, caliper bracket, and lower ball-joint assembly are installed, awaiting the rotors, calipers, and pads. The freshly machined finish of the spindle is in stark contrast to the accumulated road grime on the undercarriage. Sometime in the near future, we'll steam-clean the bottom of the car and paint some of the components. But since this is a driver, our primary goal is to get back on the road safely.
When you do a lot of mechanical...
When you do a lot of mechanical work, specifically repetitive tasks such as installing rotor seals, a specialized tool makes the job easier and the results more consistent. In this case, we took a common bolt and modified the head to form the tool shown here. This way, a precise fit can be accomplished without beating the seal into submission with a chisel or punch, which can deform it and impair its function.
It's important to tighten...
It's important to tighten the spindle nut properly. The manual says it should be tightened with a torque wrench to about 90 in-lb and then backed off and retightened by hand while spinning the rotor. This picture was taken during the hand-tightening process.
In our application, we installed...
In our application, we installed the new dual-line master cylinder with the proportioning valve mounted directly below. In some cases, such as a Max Wedge installation using the stock exhaust manifolds, the proportioning valve will have to be relocated to a different area because of the dramatic upsweep of the exhausts.
This diagram shows the line...
This diagram shows the line configuration used on our '63 Fury convertible. Because we weren't using a line-loc, we were able to use the original line from the old master cylinder to feed the rear brakes by reflaring it and using a new fitting. The original frame-mounted distribution block was retained, and its two front ports were blocked with fittings we purchased at our local NAPA store.
Another old mechanic's technique...
Another old mechanic's technique is to bench-bleed the master cylinder prior to the actual installation. Not only is it quicker and easier, there's less likelihood of brake fluid splashing on and ruining painted surfaces under the hood or on the fenders. It's amazing how far this stuff can squirt if you're not careful, so the less bleeding you have to do with the unit on the car, the better.
In the event a line-loc is...
In the event a line-loc is used, the original main line, reflared and refitted, is used to feed the rear brakes. One of the two outlets at the rear of the proportioning valve (front-brake connections) is plugged, and a single line is run to the inlet port of the line-loc. A line is then run from each of the line-loc outlet ports to each individual front brake. Note: In many cases, NHRA rules require the line-loc to be installed after the proportioning valve, rather than between the master cylinder and the proportioning valve. Check with your local tech inspector.
Most metal parts are shipped...
Most metal parts are shipped with a coating of cosmoline or other preservative to protect the surface and prevent rust. Left intact, this coating can cause the rotors and pads to glaze, resulting in brake squeal and diminished stopping capacity. It's important, therefore, that the rotors be wiped thoroughly with a good quality brake cleaner that cleans the surface without leaving any residue of its own.
The instruction sheet was...
The instruction sheet was not specific as to what side of the rotors the calipers belong on, and we found out later that the trailing edge was not correct for this application (although most of the applications we've seen had them mounted this way). The brakes worked fine, but the angle of the flex line was such that years of use might have resulted in premature failure. When the calipers were correctly mounted on the leading edge (front), the alignment was much better, and the life expectancy of the flex lines was normalized.
A careful assessment of the...
A careful assessment of the suspension showed the ball joints and bushings to be in good shape, but the shock absorbers were history. We chose a set of MonroeMatic Plus gas shocks for their excellent suspension control and anti-dive characteristics on hard braking. When you're out in traffic with a bunch of modern vehicles that stop like race cars, you need all the control you can get (if you don't want to be picking pieces of Honda out of your grille).