The Master Plan
Part 2: Completing our Wilwood disc brake conversion
In last month’s issue we set about converting our '57 Ford Ranch Wagon from early Camaro disc brakes to modern, aluminum four-piston disc brakes from Wilwood Disc Brakes. The conversion proved to be very straightforward and we were more than pleased with the increased rotor size, the black anodized calipers, and the substantial reduction in unspring weight.
With the brakes installed on the spindles it is time to pop the hood and swap our master cylinder. Once again we used Wilwood components to ensure compatibility. Since we are using a power booster, Wilwood recommended a 1-1/8-inch bore dual master cylinder. Also, since the drum brakes will remain on the rear of the car, a proportioning valve and distribution block were included in the order. This will greatly simplify the installation and ensure the proper pressure for both the front disc and rear drum brakes.
First we unpacked the master cylinder and proportioning valve kit and completely read the instruction sheet. The clear instructions also help you understand the task at hand, which ultimately saved us time. The kit comes with a selection of fittings, ensuring your existing brake lines and fittings will thread into the proportioning valve. The proportioning
valve mount is held in place by the two nuts that hold the master cylinder to the power brake booster and Wilwood was kind enough to include two small stainless steel brake lines that connect from the master cylinder to the proportioning valve, but we’re getting a bit ahead of ourselves.
First, we determined which side of the master cylinder we would use for the brake lines. Since the master cylinder has ports on both sides you must plug one side with the supplied plugs and use the other side to power your brakes. We put our soft jaws in the vise and firmly clamped the master cylinder in the vise so we could install and tighten the two plugs. Don’t over-tighten the vise; remember this is an aluminum master cylinder so you don’t want to risk breaking off one of the mounting ears.
With one side of the master cylinder plugged, it is time to bench bleed the master cylinder using the supplied bench bleeding kit. There are actually two ways to do this. One, as the name implies, is to bleed the master cylinder clamped in the vise on the bench using
a large punch to move the cylinder in and out until the air is evacuated from the cylinder. The other way is to mount the master cylinder on the car, install the master cylinder bleeding kit, and bleed the master cylinder using the brake pedal in the car to slowly move the master cylinder in and out until all the air is purged from the cylinder. We bench bled the cylinder mostly because it was easier to photograph, but often find the second method easier. Either way, be certain all the air is out of the master cylinder.
Next, mount the proportioning valve and distribution block along with the master cylinder on the car. The Wilwood master cylinder is designed to work with a long pushrod from the brake pedal, or you can insert a bushing into the master cylinder so the short pushrod from a power brake booster will work. Since we are using power brakes, we inserted the bushing prior to mounting the master cylinder to our brake booster.
We mounted everything finger tight; the master cylinder/brake booster bracket and the distribution block/
proportioning valve. Then we installed the Wilwood pre-formed stainless steel brake lines between the master cylinder and the distribution block. Finally, we connected the existing brake lines on the car to the proper ports on the distribution block. It should be noted the distribution block comes with two front brake ports. You can either run a separate line to each front brake caliper or plug one port and utilize a tee in the line to split to the front brakes. Since our existing line had a tee on the framerail we plugged one of the front brake ports with a proper inverted flare plug from the local parts store (this is not a pipe thread). We were fortunate enough to bend the existing rear brake line to align with the new port on the proportioning block. We were not as fortunate on the front brake line and had to fabricate a new section of brake line to connect from the aforementioned tee to the proportioning block. Once again, inverted flare fittings are used throughout the installation.
With the brake lines connected finger tight we now tightened the two bolts holding the proportioning valve/ distribution block to the master cylinder.
Then, using the proper line wrench– style wrenches we tightened all of the inverted flare nuts. We also checked the plugs on the opposite side of the master cylinder to ensure they were tight.
A quick check of the brake pedal ensured us it was working properly and moving the master cylinder the full stroke. Next we disconnected the battery and spliced the two new wires into our existing brake light wires and plugged the wires onto the brake light switch that is supplied with the distribution block.
From here it’s a simple matter of bleeding the brakes. Since we had bench-bled the master cylinder, bleeding the brakes was very straightforward, and since the master cylinder is well above all wheel cylinders and calipers, there was no need for a residual valve. We bled the brakes beginning with the brake farthest from the master cylinder and until all air had been eliminated. We pumped the brake pedal until we had a good firm pedal and tested the brakes by holding the pressure on the brake system for at least one full minute. Then we got under the car and
examined all connections for any sign of a leak. Once we were certain the hydraulic system was properly bled and leak-free it was time for a testdrive.
First we tested the car in the driveway and the brakes seemed to be working properly. Next it was time to head to either a large, empty parking lot or in our case a certain quiet dead-end road. Once there we gave the brakes a bit more rigorous test; first 15 mph, then 20, and 30 mph. Satisfied that the brakes were working properly it was time to bed in the new brake pads with a series of light stops to build up some heat. We are fortunate to have plenty of long, lonely country roads so the bedding process continues with a series of braking from 55-60 mph down to 25 mph, with sufficient brake release time to cool and heat sink the pads. The Wilwood directions give very specific details on brake pad bedding. By now the brakes should be feeling smooth and stopping the car efficiently.
Once back home take a look at the new rotors. They should display a uniform burnishing across the face of the rotor. We made yet another
full inspection of all brake components to ensure the flex lines were not contacting any suspension components, that there were no leaks, and we even removed the cover on the master cylinder to ensure it was at the proper level.
In the end we were more than pleased with the braking on our '57 Ford Ranch Wagon. The Wilwood brakes provided confident, positive braking far superior in every way to the old Camaro disc brakes that were on the car. Even the pedal feel is better with the Wilwood brakes, making this weekend conversion one of the best projects yet for our Ranch Wagon.
While we were able to slightly bend our rear brake line to fit the new combination valve, we had to form a new front brake line. This included using a proper bending tool and doing inverted flares on both ends of the line.
This easy-to-use Surseal Mini from Koul Tools makes a perfect flare by lapping in the inside of the inverted flare. We use it on all of our inverted flared lines for a perfect seal every time. This new line will connect from the distribution block on...
Before doing anything we testfit the master cylinder to the booster, then went inside the car to check for proper pedal travel.
Since we are running drum brakes rear and new Wilwood disc brakes up front, a proportioning valve and distribution block (aka combination valve) was ordered. It comes complete with formed lines and a new brake switch. We test-mounted the combination...
After carefully cutting out a piece of the DEI Reflect-A-Gold tape we installed it on the Wilwood master cylinder. This will not be seen after the cylinder is installed.
We installed the two supplied plugs on the right side of the master cylinder since this side points toward the engine in our car. Heat is the enemy of brake fluid and anything that has a seal inside. Since the exhaust manifold is below the master...
1932 Ford Roadster by Johnson’s Hot Rod Shop Front Tires: Firestone Deluxe Champion 5.60-15 Rear Tires: Firestone Deluxe Champion 7.50-16 Wheels: Specialty Wheel Hot Rod Steel
The master cylinder also comes with this insert that converts it from a deep bore to shallow bore master cylinder. Typically power brakes use a shallow bore master cylinder. Since we are using a power brake booster we installed the insert in the master...
The Wilwood master cylinder has ports on both sides, making it easy to plumb the proportioning valve and brake lines. Along with our power booster this 1-1/8-inch bore master cylinder will provide proper line pressure. The Wilwood master cylinder comes...
Matching the master cylinder to the other brake components is imperative for good, safe braking. We used Wilwood components exclusively in our front brake upgrade. In last month’s issue we installed the Wilwood four-piston calipers and 12-inch rotors...
We testfit all the lines before bleeding the master cylinder or introducing any brake fluid to the new system.
This pigtail and boot was supplied with the Wilwood combination valve. The push-on wires fit the new brake light switch that came pre-installed in the combination valve. We spliced the two wires into our existing brake light wires. Satisfied that all...
19-20-21 After bleeding the master cylinder we bolted it all in place, tightened the lines and checked to be certain everything was tight. We always use Wilwood Hi Temp 570 brake fluid in our hot rods. After using standard brake bleeding procedures we...