What does it mean when my truck says service trailer brake system?
It tells you that your truck’s brakes are compromised, and it needs a service. If the brake system is not maintained, it could cause a lack of braking or worse.
How do I get my brakes fixed?
There’s no need to panic if you get this message on your dashboard. You can easily get the brake system serviced by taking it to a local auto shop or dealership. The service will most likely run about $100 and should solve the problem.
If the message pops up again after you get your brakes serviced, you may need to take it back in and ask the mechanic to check if there’s a leak in the brake lines. This can be very dangerous, and your brakes could fail at any time, so make sure it is taken care of right away.
What does service brake system mean?
A service brake system is a special kind of brake system used on the trailers of semi-trucks and other large vehicles. This type of service brake system uses air pressure from an air compressor to operate. In the case where the truck has multiple trailers, each trailer may have its own self-contained air compressor to recharge the system, but most times an airline is run from the truck to each trailer.
How service brake system works
The level of brake pressure in a service brake system can be adjusted by activating or deactivating an air valve that controls the flow of air into the master cylinder. The tractor portion of semi-trucks uses hydraulics to control the brakes, but the trailers use air pressure because hydraulic fluid needs time to travel down to each brake unit. By using compressed air, the system can change the level of brake pressure in a matter of seconds instead of waiting for hydraulic fluid to move to where it is needed.
Connected together by an airline, both semi-trucks and trailers have a service brake system that operates similarly. The compressor, which is driven by a drive belt or rotary vane motor, pumps air into a master cylinder mounted on the semi-truck. Air from the master cylinder goes to each trailer’s service brake chambers through tubing called “airlines.”
To create pressure in the system, a one-way valve called a check valve is installed on each brake chamber on each trailer. Air from the master cylinder goes to the back of the check valves and into small chambers that have pistons mounted in them on all four wheels on each trailer. As air pressure builds, it forces the pistons out of their chambers and into a brake lining. The pressure on the lining creates friction that allows the trailer to slow down and eventually stop while going downhill.
A compressor can be turned off by opening an air valve called an isolation valve under the driver’s seat in the cab of the semi-truck. When activated, this valve closes off air flow from entering the master cylinder.
Conclusion
So what is the definition of a service brake system? A type of brake system used on trailers that use compressed air to pressurize braking chambers. The compressor can be activated by an isolation valve, which will shut off the supply of compressed air when opened.
