Car Care
Somebody Stop Me
Installing aftermarket disc brakes
Created by Dave AndersonDecades before Jim Carrey's now famous "Somebody stop me" line was uttered in the comic movie "The Mask," many drivers were probably thinking the same thing when braking their early Pontiac musclecars. In fact, not until 1967 did Pontiac even offer a front disc-brake option. Rear discs were not an option until 1979, and then only with the WS6 package. In 1964, metallic drum brakes were available on the GTO, but suffered from a malady then known as "morning sickness." In other words, until you warmed up the brakes, the car was downright dangerous to drive in a must-stop scenario.
'66 Meets 2003
Factory disc brakes were quite an improvement. However, many racers still turned to the aftermarket for lighter brakes in order to improve their front-to-rear weight distribution. Unfortunately, most of these lightweight kits were not suited to street driving. In addition, some of these early conversions required a great deal of home engineering to install in certain vehicles. All that has mercifully changed.
When it came time to arm the re-created 1966 Pontiac GTO "GeeTO Tiger" with sufficient stopping power to match its superior horsepower, we called Stainless Steel Brakes in Clarence, NY, provider of a wide variety of conversion kits. For the front, we ordered the Super Duty A 123-6 Disc-Brake Kit. For the rear, however, we thought we might have a problem. The Moser 12-bolt rear end we obtained was assembled with Ford bearings and flanges. The Stainless Steel A 125 disc brake conversion kit was available for the traditional 12-bolt. Fortunately, Stainless provided us with special mounting brackets to accommodate our particular rear end.
Installation
Compared to the jerry-rigging some of us suffered with in years past, these kits practically fell on. Instructions supplied were well written and easy to understand, as were the component illustrations—and no "missing parts" here. Because the GeeTO Tiger sports a very aggressive camshaft with idle vacuum well below the required 16 inches, we ordered and installed a special vacuum pump kit, too. Click on the accompanying photos illustrating the installation.
Step 1
Our front disc kit came with two piston aluminum calipers, 12-inch vented slotted rotors, mounting brackets, pads, hardware, adjustable proportioning valve, adapter lines, stainless steel flex hoses, master cylinder, 9-inch booster, seals, bearings and easy-to-read instructions.
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Step 2
This is the original front drum brake on the GeeTO Tiger. The disc-brake conversion is designed as a bolt-on upgrade utilizing the original spindle and drum hub.
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Step 3
The original front drums and backing plates were discarded. After installing new bearings and seals in the original drum hub, the drum hub is re-installed. It's also recommended that new wheel studs be installed as shown here.
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Step 4
The spindle caliper mounting brackets are stamped left and right and must be installed in the proper direction. Two special top anchor bolts and two 1/2-inch bolts secure the brackets to the spindle.
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Step 5
The rotor is placed over the original hub and the caliper is installed using the hardware provided. With the stainless steel flex line attached to the caliper, the front disc-brake conversion is complete.
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Step 6
The vacuum pump kit includes the vacuum pump, relay switch, distributor/vacuum switch, wiring, rubber insulators and a length of vacuum hose.
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Step 7
Since the battery had been relocated to the trunk, the vacuum pump was mounted with the supplied insulators to the core support. The vacuum line was routed atop the fender well rearward to the booster.
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Step 8
As mentioned, this kit came with a 9-inch booster, but to clear the tall valve covers we used a 7-inch booster. The adjustable proportioning valve with gauge was then installed in the rear brake line. Note the vacuum hose extended from the forward-mounted vacuum pump.
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Step 9
The rear brake kit came with rotors, calipers with built-in parking brakes, dust shields, brake-line adapters, mounting brackets, hardware and instructions. Since the 12-bolt rear end was assembled with big Ford bearings and housing ends, we opted for a kit with GM pattern rotors.
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Step 10
Here is one half of the Ford bearing retainer. This split retainer is also the main caliper-mounting bracket. The caliper-mounting bolts must be fitted prior to installing the retainer, as the length of the bolts won't permit access once the axle is retained.
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Step 11
Here the main caliper-mounting bracket is installed with the dust shields.
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Step 12
Caliper mounts are shown here secured to the main caliper-mounting bracket.
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Step 13
With the brackets in place and the rotor installed, the caliper itself can be mounted.
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Step 14
Positioning the pads in place completes the installation of the caliper.
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Step 15
The brake-line adapters are installed. The Moser rear end doesn't provide clips for attachment of the brake lines, so Moser recommends they be secured to the axle tubes with nylon tie-straps as shown. The complete assembly is ready for bringing the GeeTO Tiger to a halt.
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