DCA70SSJU4i
TRAILER MAINTENANCE
The following trailer maintenance guidelines are intended
to assist the operator in preventive maintenance.
Properly functioning brake shoes and drums are essential
to ensure safety. The brakes should be inspected the first
200 miles of operation. This will allow the brake shoes and
drums to seat properly. After the first 200 mile interval,
inspect the brakes every 3,000 miles. If driving over rough
terrain, inspect the brakes more frequently.
If your trailer has hydraulic brakes, they function the same
way the surge brakes do on your tow vehicle. The hydraulic
braking system must be inspected at least as often as the
brakes on the tow vehicle, but no less than once per year.
This inspection includes an assessment of the condition
and proper operation of the wheel cylinders, brake shoes,
brake drums and hubs.
Most axles are fitted with a brake mechanism that will adjust
the brakes during a hard stop. However, some braking
systems are not automatically adjusted by hard stopping.
These brakes require manual adjustment. The following
steps apply to adjust most manually adjustable brakes.
1. Jack up the trailer and secure it on adequate capacity
jackstands.
2. Be sure the wheel and brake drum rotate freely.
3. Remove the adjusting-hole cover from the adjusting
slot on the bottom of the brake backing plate.
4. With a screwdriver or standard adjusting tool, rotate the
starwheel of the adjuster assembly to expand the brake
shoes. Adjust the brake shoes out until the pressure
of the linings against the drum makes the wheel very
difficult to turn. Note: Your trailer maybe equipped with
drop spindle axles. See axle manual for your axle type.
You will need a modified adjusting tool for adjusting
the brakes in these axles. With drop spindle axles, a
modified adjusting tool with about an 80 degree angle
should be used.
5. Rotate the starwheel in the opposite direction until the
wheel turns freely with a slight drag.
6. Replace the adjusting-hole cover.
7. Repeat the above procedure on all brakes.
8. Lower the trailer to the ground.
Check the fluid level in the master cylinder reservoir at least
every three months. If you tow your trailer an average of
1,000 miles per month in a hot and dry environment, you
must check the brake fluid level once a month. The brake
fluid reservoir is located on the tongue of the trailer. Always
fill with clean, uncontaminated DOT 4 brake fluid.
Figure 64 below displays the major hydraulic brake
components that will require inspection and maintenance.
Please inspect these components as required using steps
1 through 6 as referenced in the “Manually Adjusting The
Brakes” section on this page. See Table 1 for Hydraulic
Brake Troubleshooting.
Figure 64. Hydraulic Brake Components
The hydraulic brake actuator (Figure 65) is the mechanism
that activates the trailer’s brake system. This actuator
changes fluid power into mechanical power. Therefore, the
fluid level must be checked frequently to assure that the
brakes function properly.
Figure 65. Hydraulic Brake Actuator
HYDRAULIC
BRAKE
FLUID
RESERVOIR