Disc brake technology has become the predominant method of bringing vehicles to a halt but drum brakes still have their place, particularly on light commercial vehicles, from bakkies to vans and mini-bus taxis which typically have disc brakes on the front axle and drum brakes on the rear axle. While drum brakes generally have a longer service life than disc brakes, commercial vehicles clock up a lot more mileage over a given period than passenger cars, leading to similar brake service intervals.
With many more ‘moving parts’ than a disc brake system, servicing or replacing drum brakes can seem a daunting prospect for the novice auto technician. This needn’t be the case.With these tips, the task of overhauling a set of drum brakes will become a breeze, delivering optimum safety and cost-savings to your customers.
Order the model-specific BETA or DOE drum brake components, tools and consumables from www.startmycar.co.zaThese will include: New brake drums; brake shoes, spring kits, brake adjusters and wheel cylinders. You will also need Shield Brake and Tool Cleaner, Brake Fluid, Anti-Seize Paste, Sand Paper, a Wire Brush and a set of tools including: a Flat-Head Screwdriver, Vice Grips, Pliers, Four-Pound Hammer, Spanners and Socket Set.
Follow these steps...
• Wear safety glasses.
• Jack the car up using jack stands and wheel chocks.
• Release the hand brake (aka park/emergency brake).
• Remove the wheels.
• Remove the brake drums. If they don’t slide off the axle hub easily, give them a couple of hefty knocks with the four-pound hammer.
• Spray the entire brake drum assembly with the shield Brake Cleaner and allow brake lining residue to clear from the assembly.
• Take clear photographs of the brake drum set-up for reference when replacing parts.
• Remove upper springs and self-adjuster cable from the spring kit.
• Remove brake shoe springs and spring pins.
• Slide the brake shoes off the assembly.
• Remove the park brake link arm.
• Remove lower brake springs.
• Detach the park brake cable from the shoe.
• Clean the brake shoe contact points and the brake assembly backing plate with Shield Brake Cleaner.
• Remove the brake fluid line behind the backing plate.
• Remove the wheel cylinder.
• Clean the wheel cylinder pins with sandpaper or wire brush.
Now for the fitment of new (and/or existing) parts using your photos as a reference...
• Fit the new wheel cylinder and wheel cylinder pins.
• Re-attach the brake fluid line.
• Clean and refit the park brake lever to the new brake shoe.
• Fit the brake-adjust lever.• Apply a dab of anti-seize paste to lubricate the contact points on the backing plate.
• Refit the park brake lever to the rear shoe.
• Fit the new brake shoes and the supplied BETA or DOE brake shoe springs and pins.
• Refit the park brake link and springs.
• Fit new brake adjuster, applying a small amount of anti-seize paste to the threads on each end.
• Replace lower spring and self-adjusting cable.• Replace upper springs and park brake cable and cable guide.
• Now fit the new brake drums. Wipe down the insides of the drums using a cloth and brake cleaner to remove any oil.
• Bleed the brakes and top up the master cylinder with OE-specified brake fluid. Pump the brake pedal to check for correct brake pressure.
• Finally, spin the brake drums to check for any friction/resistance. Remove the drum and set the brake adjuster so that the gap between the shoes and drum is optimum, i.e. a tiny gap separating them.Now put the wheels on and take the vehicle for a slow test drive.
Bottom line – With a photo of the drum brake set-up and OE-quality drum brake replacements parts from www.startmycar.co.za , you can make drum brake overhauling your speciality.