Peterbilt 325 2017, Operator'S Manual, Page: 199 / 392

SUSPENSION
WARNING!
• The rear of a vehicle will
drop about 3 1/2 inches (88
mm) when the air springs are
deflated. Ensure that no persons
or objects that could be killed,
injured or damaged are under
the vehicle before deflating the
air springs.
• To minimize risk of death,
personal injury or property
damage, do not use a dump
valve to deflate the air springs.
Rotate the height control
valve(s) manually to ensure
positive control of air spring
deflation.
• To minimize risk of death or
personal injury, keep away from
air springs as they are being
inflated.
4. Rotate the valve either clockwise or
counterclockwise until air pressure in
the air springs provides the ride height
specified for that suspension. Measure
the ride height from the bottom of the
frame rail to the approximate centerline
of the rearmost drive axle hub:
•
For tandem axles, make the
vertical measurement at the
centerline of the suspension (see
illustration on page 4-58).
•
For a single axle, make the
measurement in front of the axle,
in the area forward of the tires but
not past the suspension bracket.
5. When at the correct ride height,
ensure that the height control valve
lever is in the neutral position, then
install either the built-in alignment
pin or a 1/8-inch (3 mm) dowel (see
illustration on page 4-58).
6. Torque the mounting fasteners to
55-75 Lb. in. (6.2-8.5 Nm.).
7. Remove the alignment pin or dowel.
8. Repeat Steps 2 through 6 above
for the RH valve on vehicles with a
dual-valve system.
(03/17) Y53-6060-1C1
4-59
4