32
MAINTENANCE
and measure the distance to the 1/2” pin. The difference
between these 2 measurements is the stroke. The stroke,
or difference between these two measurements must be
less than as shown on the following charts.
Chamber Type
Maximum Stroke
12
less than 1-3/8”
16
less than 1-3/4”
20
less than 1-3/4”
24
less than 1-3/4”
30
less than 2”
Long Stroke Chamber
Maximum Stroke
16
less than 2”
20
less than 2”
24 (below 3” max stroke)
less than 2”
24 (3” max stroke version) less than 2 1/2”
30
less than 2 1/2”
The auto-check pointer will point to the home posi-
tion to verify proper installation.
WARNING
An auto slack adjuster should never have to
manually adjusted while in service. The only
time it should be manually adjusted is during
installation or at brake relining. By constantly
manually adjusting the hex shaft the internal
clutch life can be shortened. The proper way
of checking an auto slack to see if it is working
within specifications is to measure the working
stroke.
CAUTION
Check the brake adjustment frequently during
the first 500 miles after relining. Overloading
or using only the trailer brakes to stop the
complete tractor-trailer unit will cause the
heat absorption capacity of the brake to be
exceeded. Hotter brake linings and drums,
longer stopping distances, and shorter brake
lining life will result.
Working At Rear Of Units
When performing any maintenance or adjustments at
the rear of the unit, the door lock valve must be closed
to prevent any inadvertant movement of the rear doors,
which could cause serious injury. The door lock valve
location is shown on decals on the left side of the unit,
just forward of the rear axles on trailers and over the
axles on chassis units.
Conveyor System Maintenance
Door Lock Valve
5003174
Door
Lock
Valve
5003175
5002625
CAUTION
Doors may creep
closed.
Close ball valve before
working near or around
rear cargo doors.