Lesson 2/Learning Event 3
AFTER ROAD-TEST INSPECTION
This inspection is made to see if anything unusual happened during
the road test.
Check the temperature of the brake drums on the truck and trailer.
They should be warm but not very hot.
Check to see if there is any indication of new brake fluid leaks.
Check the trailer brake air line connections for leaks.
After completing an inspection and road test of a vehicle braking
system, you should have a pretty good idea of what the system is
doing wrong. The next thing to do is to find out what is making the
system do something wrong. This is known as troubleshooting and
consists of isolating or locating the part or parts that are causing
the trouble. We will refer to the major trouble as a malfunction and
discuss several things that could cause each malfunction as well as
what should be done to correct the trouble.
You will sometimes find a braking system that will not press the
brake linings against the drums hard enough to stop the vehicle in
the proper distance.
Check the wheel brake lining condition and adjustment. If the
linings are worn badly, they should be replaced. If they are too far
Check the air pressure system to ensure there is a minimum of 80 to
105 PSI. Correct any leaks and replace components that are not
Check the airhydraulic cylinder for proper operation. Certain tests
(which we will discuss later) can be made to determine if this
component is doing its job.