Why Certain Brakes Perform – Or Don’t – In Calgary
Buying trends indicate Albertans tend to purchase high-end, light trucks with hauling capacity, or fuel-efficient sedans. Hybrids also are growing in popularity. What do these dramatically different vehicles have in common? Each of these vehicles face challenges driving through Calgary’s changeable weather.
Calgary residents see snow almost 90 days of the year. Warm, Chinook winds turn much of that snow into slush, creating potentially dangerous roads. Our province’s cold temperatures and wet roads means the vehicle you buy needs to have high-quality brakes that function in all weather conditions.
We debunk truck and car braking systems, how brakes work, and when they don’t, so that you can make an informed decision the next time you are in a car lot.
Service Brakes: What They Do to Keep You Safe
Brakes use coefficient friction, the force required to pressure an object. The heavier the vehicle, the more force the brake pad needs to slow down the tires. Pick-up trucks and SUVS need brakes that apply more coefficient friction than lighter sedans do because they weigh more.
Because of this difference in requirements for friction, trucks and sedan have different braking systems. Specifically light trucks tend to have disc brakes, whereas sedans have drum brakes or a combination of disc and drum brakes.
For example, one of Alberta’s best-selling truck series, the Ford F-Series, have power four-wheel anti-lock vented disc brakes. Even the smallest truck in the F-Series, the F-150 weighs between 5,000 and 6,000lbs with a maximum towing capacity of 11,300lbs. The truck’s weight, especially if it is towing or carrying heavy items in the truck bed, requires the unmatched stopping power of disc brakes on all four wheels. Anti-lock brakes are the truck’s secondary braking system in case the disc brakes lock up.
By comparison, the Honda Civic, one of Canada’s best-selling sedans, weighs between 2750 and 2930lbs. This sedan uses a combination of front disc brakes and rear drum brakes to maintain the car’s low cost.
Disc and drum brakes offer different benefits. Find out how each brake works, and what their downfalls are.
Disc and Drum Brakes: How They Differ
Service brakes are your car or truck’s primary braking system. You hit the pedal. The service brakes slow your car. Here’s how both kinds of brakes make that happen:
Where You Find Drum Brakes: Many mid-grade cars and trucks use a combination of disc brakes in the front and drum brakes in the rear. This grouping compromises the relatively high cost of disc brakes with less expensive, easy-to-fix drum brakes. Drum brakes cost much less than disc brakes, and integrate easily with emergency brake systems. Drum brakes can be challenging to service because they contain a lot of parts.
How It Works: Drum brakes use two brake pads, a small piston, a drum, an adjuster arm, and springs to slow the car’s wheels. When you hit brake pedal, the piston push two brake pads against the brake’s drum in a wedging motion. The adjuster arm keeps the brake pads close to the drum, and springs release the pads from the drum.
When They Don’t: The downfall of drum brakes is that they wear down with high-speed, sudden braking. Quick braking at high speeds generate heat the brake’s components up. Once hot, the brakes can’t transmit force, or coefficient friction, as effectively. You can avoid this breakdown by changing out the brake shoes at the first sign of wear and tear.
Where You Find Disc Brakes: Compared to a race car or other high-speed vehicles, most consumer-model cars travel at moderate speeds. Therefore, most of them don’t require the formidable stopping power of four disc brakes. Most mid-grade cars have disc brakes on the front wheels. The disc-and-drum combination in mid-grade also prevents sacrificing performance. Trucks, because of their weight and hauling capacity, often have disc brakes on all four wheels. High-performance such as race cars carry speed into corners, and then pump the brakes late into the turn.
How They Work: Two brake pads clamp down on the rotor, mounted on the wheel’s hub. Because the rotors are on the wheel’s exterior, they receive a constant supply of fresh air. This ventilation process prevents disc brakes from overheating.
When They Don’t: The biggest downfall of disc brakes is their high manufacturing cost. However, they are more effective than drum brakes. Disc brakes have a wear indicator on their brake pads. Over time, the wear indicator gradual loses material until the pads rub against the disc. In addition to pads getting worn down, one of disc brake’s rotors gradually lose their flatness and need to be refinished.
Emergency brakes can’t structurally integrate with four-wheel disc brakes. Therefore, manufacturers mount a separate drum brake onto the rear wheels’ hub and integrate the drum brake with an emergency brake.
Don’t let your brakes get stuck in the cold. A Calgary-based brake specialist can check your brakes for free, and help to replace them.