Landoll 330A, Operator'S Manual

Page: 43 / 62

4-8.2
Spring Air Brake Chamber
Repair or replace faulty units. Check the con-
densation 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 dia-
phragm and any marginal parts should be re-
placed. The spring chamber should not be serv-
iced. Replace entire unit if spring chamber be-
comes faulty. When replacing the service dia-
phragm, replace the corresponding 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 necessary.
WARNING
THE SPRING BRAKE CHAMBER EM-
PLOYS A SPRING WITH HIGH FORCES.
SERVICE SHOULD NOT BE AT-
TEMPTED. SERIOUS INJURY OR
DEATH MAY RESULT.
a. Caging the Power Spring
1. Chock the semitrailer wheels.
2. Remove dust cap from spring brake
chamber.
3. Remove the release bolt from it’s holding
brackets and insert it into the spring brake
chamber. DO NOT USE AN IMPACT
WRENCH TO CAGE THE SPRING
BRAKE!
4. T urn the 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 semitrailer with brake
manually released.
6. To reset the spring brake, turn the release
bolt until the spring is released. Remove
the release bolt and store it in its brackets.
7. Snap the dust cap back in place on the
chamber.
b. Removal
1. Chock all tractor and semitrailer 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 4-8.2 a.
4. Disconnect the slack adjuster from the
connecting rod by removing the clevis pin
( See Figure 4-12) .
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.
c. Installation
1. CAGE THE POWER SPRING following the
steps outlined in Section 4-8.2 a.
2. Position the inlet ports by loosening the
service chamber clamp bands and rotating
the center housing so the ports align with
marks made during disassembly. Then
re-tighten the clamp bands.
3. Loosen the clamp bands on the spring
brake chamber and rotate the chamber
housing until the breather hole faces
downward. Re-tighten the clamp bands.
4. Remount the brake chamber on the axle
brackets and reconnect the air service
hoses and the slack adjuster connecting
rod (See Figure 4-12).
4-15
Figure 4-10 Brake Lining Wear