For classic truck and car owners, upgrading the braking system is essential for both safety and performance. Classic Performance Products (CPP) offers a cost-effective, high-quality solution with its firewall-mounted power brake booster and master cylinder kits. These kits are specifically designed for vehicles like the 1966 Chevrolet II and early model Chevrolets, and they include components such as dual reservoir master cylinders, proportioning valves, and hard lines for a complete disc/drum brake system.
This article provides a step-by-step technical overview of the CPP firewall-mounted brake booster installation process, based on the detailed instructions and insights from the manufacturer and user experiences. The information is sourced exclusively from the documentation provided, ensuring accuracy and reliability.
Overview of the CPP Brake Booster System
Classic Performance Products offers a variety of brake upgrade kits tailored for classic vehicles. One of the standout products is the CPP PN 5559FBB2 firewall-mounted power brake booster kit. This system is engineered to fit a range of classic trucks and cars, including the 1955–1959 and 1966 models of the Chevrolet II. The kit includes a 9-inch or 8-inch dual power booster, a master cylinder, a proportioning valve, and all necessary mounting hardware.
The primary advantage of this setup is its compact design, which allows for compatibility with various engine configurations, including those with full valve cover coverage. Additionally, the firewall-mount design offers greater rigidity compared to traditional under-dash setups by triangulating the firewall, dash, and steering column. This design ensures the entire braking system remains stable and secure.
The CPP kit is also notable for its affordability and ease of installation. Users have reported that the installation process is relatively straightforward, even for those with moderate mechanical experience. The kit is compatible with factory e-brake handle assemblies in some models, which simplifies the integration of the new system into existing vehicle structures.
Step-by-Step Installation Process
Preparation and Firewall Modifications
Before beginning the installation, several preparatory steps are necessary. One of the first tasks is to remove the original mounting hardware from the firewall. This involves knocking out two studs that secure the firewall bracket. To accomplish this, the nuts are threaded onto the studs, and a firm blow with a hammer dislodges the studs.
Next, the firewall requires a ⅜-inch hole to accommodate the three-bolt design of the CPP brake booster. Fortunately, the factory has already left a dimple at the correct location, making it easier to start the drilling process. Once the hole is drilled, the new firewall-mount bracket is installed using the supplied hardware.
The CPP booster assembly comes pre-assembled with a dual reservoir master cylinder, proportioning valve, and hard lines already installed. This design simplifies the installation process by reducing the need for additional components or assembly steps.
Installing the Brake Booster and Master Cylinder
The next step is to position the new booster and master cylinder unit into place. The space between the firewall and the shock towers is limited, so careful alignment is required. The three nuts and clevis pin are removed from the back of the brake booster before attempting to slide the unit into place.
Once the studs are inserted through the firewall, the clevis must be aligned with the brake pedal. This alignment is critical for proper operation of the braking system. The clevis is then attached to the pedal using the supplied pin. This step is performed from under the dash, where the three nuts can be tightened using a series of extension and swivel tools.
Caliper and Rotor Installation
The CPP disc brake conversion kit includes all necessary components for front-wheel upgrades, including calipers, rotors, and Grade 8 hardware. The installation of these components begins with the spindle, where the CPP disc brake kit replaces the traditional backing plate.
Grade 8 bolts are used to secure the caliper bracket to the original spindle. The upper bolt is designed with a thin head to allow for rotor clearance, while the lower bolt passes through the spindle and steering arm. A locking nut is used on the back side to ensure the assembly remains secure.
The rotor is installed after the inner wheel bearing and seal are placed on the spindle. The rotor is then slid onto the stock spindle and secured with the outer bearing and washer. The castle nut is tightened to seat the components properly, and the rotor is rotated to distribute the grease and allow for cotter pin installation.
The caliper assembly is then mounted over the rotor, with the bolts tightened using a ⅜-inch Allen wrench socket. This ensures the caliper is properly aligned and ready for operation.
Vacuum Line and Fluid System Setup
Since many classic vehicles, including the 1966 Chevy II, originally came with manual brakes, they may lack a vacuum source for the booster. CPP provides a 90-degree fitting that threads into the intake manifold, allowing the vacuum line to be connected.
The rubber hose is trimmed to size and installed on the new vacuum port. It is then routed from the intake manifold to the brake booster. This ensures the booster operates effectively by using engine vacuum to amplify the braking force.
After the vacuum system is installed, the brake fluid system is prepared. CPP includes a bench bleeding kit that consists of plastic fittings, clear lines, and a small clamp. The master cylinder is filled with fluid, and the brake pedal is pressed slowly until no bubbles appear in the clear lines. This ensures the system is free of air and ready for use.
Hard lines are connected to the flex hoses using a banjo-style fitting. Two washers are included to ensure a secure and leak-free connection. The hard lines are then tightened to complete the fluid system setup.
Key Technical Considerations
Compatibility and Design Features
The CPP firewall-mounted brake booster is designed to be highly compatible with a range of classic vehicles. The kit includes different booster sizes—9-inch and 8-inch—to accommodate various model years and configurations. The 9-inch booster is recommended for models like the 1966 Chevy II, while the 8-inch version is suitable for earlier models such as the 1955–1959 Chevrolets.
The dual reservoir master cylinder is a key safety feature. Unlike the older single-pot design, which could fail entirely in the event of a leak, the dual reservoir system ensures that at least one circuit remains operational. This significantly improves the reliability and safety of the braking system.
The proportioning valve included in the kit helps balance the braking force between the front and rear wheels. This is particularly important in vehicles with disc brakes on the front and drums on the rear, as it prevents the rear wheels from locking up under heavy braking.
Installation Challenges and Solutions
One of the main challenges during installation is the limited space between the firewall and the shock towers. This makes it difficult to maneuver the new booster and master cylinder into position. To overcome this, the installation should be done with patience and attention to alignment. It may be helpful to have an assistant assist with the positioning of the unit from inside the vehicle.
Another potential issue is ensuring that the clevis is properly aligned with the brake pedal. Misalignment can lead to improper pedal travel or excessive resistance. It is important to double-check the alignment and make any necessary adjustments before tightening the nuts.
The vacuum line routing can also be a challenge, particularly in vehicles with limited clearance under the hood. The vacuum line should be routed carefully to avoid contact with hot components or moving parts. Using zip ties or clips can help secure the line in place and prevent it from coming loose during operation.
Maintenance and Longevity
Once the CPP brake booster is installed, regular maintenance is essential for ensuring long-term performance. This includes checking the brake fluid level, inspecting the lines and fittings for leaks, and ensuring the vacuum line is intact and properly connected.
The CPP kit includes high-quality components, such as Grade 8 hardware and durable seals, which are designed to last for many years. However, like all mechanical systems, the brake booster may require occasional servicing or replacement if signs of wear or performance issues are noticed.
Conclusion
The CPP firewall-mounted brake booster and master cylinder kit provides a reliable, cost-effective upgrade for classic vehicles. The step-by-step installation process is designed to be straightforward, with most of the components pre-assembled for ease of use. The compact design and compatibility with various models make it an excellent choice for owners of classic trucks and cars.
By following the detailed instructions and paying attention to key technical considerations such as alignment and vacuum system setup, users can ensure a successful and safe installation. The CPP kit not only improves the performance of the braking system but also enhances the overall driving experience by providing a modern, reliable braking solution for classic vehicles.
For those seeking to upgrade their classic car or truck, the CPP firewall-mounted brake booster is a highly recommended option that delivers both functionality and value.