Landoll 345B Operator's Manual page 44

4-8.2 Spring Air Brake
Check for faulty units. Check the condensation
holes on the underside of the brake chambers to
make sure they are open. The spring brake has
two brake chambers, a service chamber and an
emergency chamber or spring chamber. Service
brake chambers should be disassembled and
cleaned at 50,000 miles or yearly. The diaphragm
and any marginal parts should be replaced. When
replacing the service diaphragm, replace the corre-
sponding parts for the other chamber on the same
axle (to aid in even brake application and release).
Examine yoke pin for wear and replace as neces-
sary. The spring chamber should not be serviced.
Replace entire unit (both service and spring cham-
ber) if spring chamber becomes faulty.
WARNING
THE SPRING BRAKE CHAMBER EM-
PLOYS A SPRING WITH HIGH FORCES.
S ER VI C E S HO UL D NO T BE AT-
TEMPTED. SERIOUS INJURY OR
DEATH MAY RESULT.
4-8.3 Replacing the Spring Air Brake Unit
a. Caging the Power Spring in the Spring
Chamber
1. Chock the trailer wheels.
2. Remove dust cap from the rear of the spring
brake chamber (See Figure 4-10).
4-14
Figure 4-9 Brake Lining Wear
3. Remove the release bolt from it's holding
brackets. Insert it into the spring brake
chamber until it can be rotated and hooked
into place. DO NOT USE AN IMPACT
W RE N CH TO C AG E TH E S P RING
BRAKE!
4. Turn the nut on the release bolt until the
spring brake is caged. This should be 2-1/4
to 2-1/2 inches of release bolt extension.
5. The brakes should now be released. Do
not operate loaded trailer with brake
manually released.
b. Uncaging the Power Spring in the Spring
Chamber
1. Chock the trailer wheels.
2. Turn the nut on the release bolt until the
spring is released. Remove the release bolt
and store it in its brackets.
3. Snap the dust cap back in place on the
chamber.
c. Removal of Brake Unit
1. Chock all tractor and trailer wheels and
drain the air system.
2. Mark the brake chamber for proper air line
port alignment for reassembly.
3. CAGE THE POWER SPRING following the
steps outlined in Section 4-8.3 a.
4. Disconnect the slack adjuster from the
connecting rod by removing the clevis pin
(See Figure 4-11).
5. Mark all air service lines for proper
re-installation and disconnect from the brake
chamber.
6. Remove the brake chamber from the axle
brackets.