Drum Brake Replacement Techniques

Drum Brake Replacement Techniques

• Drum brakes are a crucial component for automotive braking systems, known for durability and reliability
• Understanding the process of replacing drum brakes is vital for maintaining vehicle safety and performance
• Drum brakes have several key components that work together, including brake shoes and springs, wheel cylinders, and adjusters, converting mechanical energy to thermal energy to slow or stop the vehicle
• Replacing drum brakes involves a systematic approach of disassembly, inspection, adjustment, and reassembly to ensure optimal performance and safety

Drum Brake Components

• Backing Plate: A thin, metal-based band placed behind the drum brake; serves as a protective shield for other components; circular shape with holes and protrusions to match the standard drum brake part

• Wheel Cylinders: Components that convert fluid pressure into mechanical motion; vital for the braking mechanism; dual piston wheel cylinders are common due to accompanying leading and trailing drum types; these cylinders include housing, bleeder nut, piston boot, spring and piston

• Brake Shoes and Pads: Often found in drum brakes; a brake shoe or pad facilitates braking; brake shoes have a circle shape consisting of two semicircle shoes, and brake pads are placed on the brake shoes; brake pads are made of organic ceramic

• Return Spring: An important component in drum brake systems; responsible for returning the brake shoe to its original position upon release of pressure from brake lever or pedal; it includes an upper spring and a lower spring, with the latter maintaining the position of the brake shoes on the adjuster

• Brake Shoe Holder: Attaches the brake shoes to the backing plate in the drum brake system; consists of various parts, including pins, springs, and a pressure plate, for added support and stability to the drum brakes

• Brake Shoe Adjuster: Located at the bottom of the drum brake; its shape resembles a screw on an adjuster; adjusting the gap between the drum brake pads and the drum surface to ensure smooth braking operation

• Parking Brake Lever: A lever exclusively found in cars and designed for parking brake functionality; its construction includes two levers - park brake lever and brake shoe link; one end of the lever has a hinge attached to the brake shoe, while the other is attached to the brake cable

• Drum Brake: A component in the drum brake system, a medium for friction with brake pads to slow or stop vehicle wheels; made of cast steel with a drum or tube shape; directly connected to wheel bolts

Steps to Replace Drum Brakes

• Step 1: Wear an asbestos respirator to protect against hazardous brake dust

• Step 2: Remove the hubcap and loosen the lug nuts; block the front wheels with wheel chocks; jack up the car and secure it on jack stands; do not work on a car supported by a jack alone (use stands to guarantee safety).

• Step 3: Spray the hub of the wheel with penetrating oil (like PB Blaster)

• Step 4: Grip the brake drum edges and pull it off while wiggling it to aid removal; back off the brake adjuster to facilitate removal of the drum

• Step 5: If brake drums are held on by screws, remove them first as per needed

• Step 6: Examine the drum for any damage—scoring requires refacing or replacement. Take detailed pictures or drawings of the component setup before disassembling so you can put it back together correctly

• Step 7: Place the whole brake mechanism in a container and spray it with brake cleaner to keep the dust from becoming airborne (asbestos dust is hazardous)

• Step 8: Compare the new brake shoes with the old ones; ensure they are the same shape, holes, and width

• Step 9: Dismantle the brake by removing the shoe return springs, detaching the parking brake lever, and removing retaining pins and springs; spread the shoes apart from the top and disengage the shoes from the wheel cylinder pins

• Step 10: Carefully reassemble the brake components using cleaning materials and reattaching necessary parts like the return springs and parking brake lever

• Step 11: Check the reassembled brake components against the previously taken images or detailed drawings to ensure precise assembly and accurate placement

• Step 12: Reinstall the tire and torque the lug nuts along with reinstalling and attaching the hubcap; repeat the process on the other side; bleed the brake system and road test the vehicle to make sure everything is working properly