Please note: It is recommended that brake linings are replaced at the same time as the brake drums, as this will give the brake components an extended life. This will also allow all the critical brake components to operate safely and in equilibrium.
Brake drums should be replaced when the thickness of the drums reaches the minimum allowed thickness. This information is clearly etched on the brake drum outer periphery.
Worn brake drums will negatively affect the braking efficiency and handbrake operation of a vehicle. Driving with worn brake drums will result in brake shudder, cracked drums and can even lead to the drums disintegrating. This will all result in extensive damage to either the brake linings or brake drum assembly, and can also lead to brake fluid loss in the braking system.
Ensure the handbrake is applied to prevent the vehicle from rolling. Loosen the wheel securing nuts. Jack the vehicle up and remove the relevant wheel. Use a 2-ton trestle as a safety support beneath the vehicle.
Open the vehicle bonnet and remove the brake fluid reservoir cap. Wrap a thick absorbent cloth around the filler neck to absorb any brake fluid which might overflow.
Release the handbrake cable’s tension using the adjustment screw. This screw is normally on the handbrake assembly or underneath the vehicle.
Loosen the bleeding screw and then push the lining and the wheel cylinder pistons back. This will avoid contaminated brake fluid from returning into the brake fluid system and damaging the internal rubber components and seals. Nip the bleeding screw to avoid air from entering the brake fluid system. Carefully examine the thickness of the brake linings, and check the relevant brake fluid seals and rubbers for any damage, leaks or cracks. Replace the relevant seals and rubbers where applicable.
To fit the brake drums, check the brake linings. If the lining conforms to the required thickness, simply place the drums over the linings. If the brake system is self adjusting, then pump the brake pedal repeatedly. The brake lining to drum adjustment will be self-correcting. If the brake system requires manual adjustment, ensure that the drums fit over the brake lining assembly, with a slight resistance. If more adjustment is required, adjust the adjuster pinion until the brake drum fits over the brake lining assembly, again with a slight resistance.
Refit the wheel to the vehicle. Adjust the handbrake cable until the handbrake pulls tight in three or four clicks. Pump the brake pedal a few times to ensure that the brake assembly is operating correctly and that the wheels don’t bind/ lock up during normal operation.
Repeat the above procedure on the opposite wheel. After the brake drums are replaced, test drive the vehicle at a slow speed to ensure that the safety critical components in the vehicle all operate correctly and in equilibrium.
Once both brake drums have been replaced, remove the cloth from the brake reservoir and check the brake fluid level. Top up the brake fluid level if necessary, and replace the brake reservoir cap.
Remove the trestle and lower the vehicle to the ground.
USEFUL TIP 1:
For the first few kilometres after replacing the brake drums, apply the brakes gently to allow the brake linings to bed in properly against the brake drum mating surface area.
USEFUL TIP 2:
A regular inspection of your vehicle’s brake components is essential for your safety, and these should be checked at least every two months.
USEFUL TIP 3:
Replace your vehicle’s brake fluid once every 12 – 24 months.