TM 9-2330 -326 -14&P
H-37. AUTOMATIC SLACK ADJUSTERS (Cont.)
HOW TO MEASURE PUSH ROD STROKE
The maximum effective push rod stroke, as recommended by the air
brake chamber manufacturer, must be less than 2.5 inches (6.4 cm).
With a tape measure, measure the movement of the push rod from the completely released
position to the applied position (90 100 psi [621690 kPa] Brake Application).
This movement can also be measured by:
Put a mark on the push rod where it exits the air brake chamber (BRAKE RELEASED).
Apply the brake.
Measure the movement of the mark to the face of the air brake chamber housing.
BRAKE RELINE/CHECKING PROCEDURE
Rotate the adjustment hex COUNTER-CLOCKWISE approximately 1/2 turn to create excessive
brake lining to drum clearance.
Apply the brakes.
On release of brakes observe the adjustment hex rotation. This rotation indicates the ASA is
making an adjustment and is working properly.
Placing a 7/16-inch (11 mm) box end wrench on the hex adjustment
will make the movement easier to see.
On each subsequent brake release, the amount of adjustment and push rod stroke will be
reduced until proper clearance is achieved.
During brake reline, check the de-adjustment torque. Place a 7/16 -inch (11 mm) torque wrench
on the adjustment hex. Turn the hex COUNTER-CLOCKWISE and check that the clutch does
not slip at a torque LESS than 13 ft -lb (17.6 Nm). A ratcheting sou nd should occur. If the clutch
slips at a lesser torque (less than 13 ft -lb [17.6 Nm]) then the ASA must be replaced.