edit: Solved. Thanks guys
In: Engineering
Heavy duty vehicles like buses and trucks use air brakes, unlike the typical care or small truck which uses hydraulic brakes. There is an onboard compressor that is driven off the motor. There are also storage tanks to keep about 100 psi of pressurized air. The occasional “TSSSS” sound could either be the air governor “popping off” or releasing air when too much has built up in the storage tanks/system. This air is used to hold the brake pads off the brake drum or disc, hence the brakes are released and the vehicle is ready to and able to roll. When a heavy duty vehicle’s driver pushes on the brake pedal, air is released from the system releasing the pressure thru valves located near the brakes on each axle which allows the brake pads to then engage the brake drum or disc at each wheel, slowing the vehicle. Applying the brakes will also cause the “TSSSS” you when your near a heavy duty vehicle.
Latest Answers