Hino 600, Workshop Manual, Page: 382 / 451

SERVICE BRAKE (FULL AIR BRAKE) BR02–104
COMMERCIAL VEHICLE SAFETY ALLIANCE (CVSA)
GUIDELINES TO MEASURE PUSH ROD TRAVEL
(ADJUSTED CHAMBER STROKE)
Use the following procedures to check in-service push rod travel (adjusted
chamber stroke) on truck or tractor air brakes with automatic slack adjust-
ers.
Hold the ruler parallel to the push rod and measure as carefully as possible.
An error in measurement can affect CVSA re-adjustment limits, which state
that "any brake 1/4-inch or more past the re-adjustment limit, or any two
brakes less than 1/4-inch beyond the re-adjustment limit will be cause for
rejection."
! WARNING
• To prevent serious eye injury, always wear safe eye protection
when you perform vehicle maintenance or service.
•
When you work on a spring chamber, carefully follow the service
instructions of the chamber manufacturer. Sudden release of a
compressed spring can cause serious personal injury.
1. MEASURE PUSH ROD TRAVEL (ADJUSTED CHAMBER STROKE)
(1) The engine must be OFF . If the brake has spring chambers, carefully
release the spring.
(2) Check the gauges in the cab to ensure that air pressure in the tanks is
100 psi (689 kPa).
(3) Determine the size and type of brake chamber you are inspecting.
(4) With the brakes released, mark the push rod where it exits the cham-
ber.
Measure and record the distance.
(5) Have another person apply and hold the brakes one full application.
(6) Measure push rod travel distance (adjusted chamber stroke) from
where the push rod exits the brake chamber to your mark on the push
rod. Measure and record the distance.
(7) To determine push rod travel (adjusted chamber stroke): Subtract
the measurement you obtained in Step (4) from the measurement you
obtained in Step (6). The difference is the push rod travel (adjusted
chamber stroke).
• Push rod travel (adjusted chamber stroke) must not be greater than
the stroke length shown in the CVSA reference charts for the size and
type of air chamber you are inspecting.
• If push rod travel (adjusted chamber stroke) is greater than the maxi-
mum stroke shown in the CVSA reference charts, inspect the slack
adjuster and replace it if necessary.
100 psi (689 kPa) in air
tank
— engine OFF
•
Spring brakes
released
•
Service brakes
not applied
Mark push rod here
to measure stroke.
•
Spring brakes
released
•
Service brakes
applied
STROKE
SHTS068020200118