4-63. AIR CHAMBER MAINTENANCE (Con't).
REMOVED FOR CLARITY
PUSHROD TRAVEL TEST
With brakes released, insert a small rod (4) through one of two inspection holes (7) in left side of air chamber (2).
Mark rod, indicating depth of penetration when contacting pushrod.
Apply brakes, insert rod (4) fully, and mark rod again.
Withdraw rod (4) and measure distance between marks. Distance between marks indicates the amount of travel
of pushrod (3).
Pushrod (3) travel requirements are as follows:
(a) Old style air chamber. Pushrod travel not less than in. (12.7 mm) and not greater than 7/8 in. (22.2 mm).
(b) New style air chamber. Pushrod travel not Iess than in. (12.7 mm) and not greater than 1 in. (3.8 cm).
If pushrod (3) travel is not correct, replace air chamber.