Trucks and their components experience challenging driving conditions and cyclical use, making replacement parts wear and break. It is recommended to check your semi truck’s brakes at least twice a year under normal driving conditions. When checking your truck’s brakes, look out for the following common signs of deterioration:
The brakes on your semi-truck are not just for stopping. They also help keep the truck on the road, especially when hauling heavy loads. Not only do your brakes need maintenance, but so does your semi-truck air brake system. This is why it is so important to have them checked regularly.
When to replace your semi truck’s brakes
- When your brakes are squeaking. Brake squealing can be due to several reasons. It could be due to dirty brake linings, which need cleaning and replacement. Or it could be the result of worn or cracked pads or rotors that need replacing.
- When your brake pedal is sinking. Your brake pedal will sink to the floor if there isn’t enough air in your braking system. The first step is to check for leaks in your tanks and hoses. If you find any leaks, they must be repaired immediately because if they aren’t fixed, and the air pressure continues to leak out, the brakes will fail, and this could cause an accident or serious injury.
- When your ABS light turns on when you apply the brakes. This indicates that your anti-lock braking system (ABS) has detected an issue with your disc brakes and automatically applied them in an effort to avoid locking up wheels and causing a skid. No matter what, you should have this checked out by a mechanic.
What are Semi Air Brakes?
A semi-air brake is the primary braking system used in trucks. It consists of a backing plate, brake shoes, linings, connecting rods, push rods, check valve, and air compressor. When the driver presses the brake pedal, the air cylinder pushes the piston rod to compress the air and deliver it to brake chambers through check valves.
The compressed air will push out the brake shoes to contact the drum surface and make the truck decelerate and stop. The semi brake also contains a parking/emergency brake. Before driving off, drivers should pump the pedal several times to ensure that this parking/emergency brake is holding correctly. This ensures that your truck does not roll away while you are moving it or while you’re at a stop sign.
How do Air Brakes Work?
When you are driving your semi-truck, the air pump inflates the air pressure in the tractor trailer air lines. This causes the braking system on the truck to depressurize and release the brakes on your truck. It also prevents the brakes from locking up when you are using them.
Semi-trailers are used to haul cargo across the country. The brakes on these trailers are different from those of cars, so it’s essential to know how to adjust them. Some semi-trailer brakes are air brakes, which require specialized tools or skills to repair. If your semi-trailer has drum brakes, there are several ways you can adjust them.
The first step is to check if the wheels lock up when applying the brake pedal. If they don’t lock, you will need to adjust the brake shoes. If they do lock, the problem is probably with the brake drums or wheel cylinders.
Adjusting semi trailer brakes
If your wheels lock up when you apply the brake, but they release when you apply the emergency brake, then your brake shoes might be adjusted incorrectly. You can fix this problem by pushing each brake shoe with a screwdriver until it sits firmly against the drum. Be careful not to damage the brake shoes when you push them down onto the drum — if you do, then you’ll need to replace both shoes and adjust them correctly before putting them back on the trailer.
Once your brake shoes are adjusted correctly and locked into place, test your trailer’s brakes again by driving slowly over a flat surface that slopes upward at a slight angle.