Semi-truck maintenance - Tips for keeping brakes fully functional
Source: FleetAnswers Braking systems are vital to any vehicle, but a semi truck is perhaps the most critical type of vehicle when it comes to the importance of brakes. When 80,000 pounds of truck and trailer are barreling down the freeway, you need to know that they will be able to stop efficiently and quickly when needed.
Brake failure is a common cause for accidents involving tractor trailers, and these accidents are an excellent cause for a lawsuit. If you wish to avoid a lawsuit for your fleet, pay close attention to proper maintenance for your brakes.
Replace Pads and Other Parts
Brakes have parts that need to be replaced on a regular basis to keep them working well. Brake shoes have indicators built into the pads that show when replacement is necessary. When you take the truck in to have the brake pads replaced, also replace the springs, pins and bushings for the brakes. The drums should also be replaced when the shoes are replaced, because they can wear down and can also develop heat cracks.
Grease the Slack Adjusters
The slack adjustors work to keep the brakes in alignment when they are used. Trucks can have either manual or automatic slack adjustors. Both need to be greased to work well.
Automatic slack adjustors will automatically keep the brakes in adjustment, while manual require you to do the adjustment yourself. Many operators forget about greasing the automatic slack adjusters, because they do not regularly use these. When they are not greased, these seize up and stop working, which eventually leads to brake failure. When greasing slack adjustors, lithium grease is a good choice.
Check and Grease the S Cams
Slack adjustors work by turning a shaft that then turns the S cams. The S cams push the brake shoe into the drum to stop the truck. S cams are equipped with bushings. When your brake shoes are changed, check the bushings as well. These may not need to be changed as frequently as the shoes, but they should be greased as part of your regular brake maintenance.
Check the Air Compression Pressure Gauge
Application pressure is a crucial part of stopping a moving truck. Check to ensure that the gauge reads greater than 60 psi before using the truck. Ideally, the pressure should run between 100 psi and 125 psi. If you are consistently falling low on application pressure, have the brakes serviced. If the pressure ever drops below 60 psi, the truck should not be used.
Check Linings and Hoses
Before using a truck, check all linings and hoses. Linings should not be soaked with lubricant and should be at least 1/4 of an inch thick. Air hoses must not have any cracks and should not appear worn. Proper brake maintenance requires replacing worn or damaged lining or hoses regularly.
When Should Brakes Be Serviced
Finally, set up a routine plan for having a professional service the brakes on your semi trucks. While the distance a truck can travel between brake service is going to vary depending on the driving habits of the driver, it's best to have the brakes inspected and maintained every time you have the truck's oil changed. This will keep the driver, the truck and everyone on the road with them as safe as possible.