Chevrolet Silverado 4500HD 2022 Manual page 361

360 Service and Maintenance
If equipped with the optional air suspension
for the rear axle, verify air suspension
height at engine oil change intervals. See
the appropriate service manual.
Suspension alignment must be maintained
at all times.
See Capacities and Specifications 0 371 for
proper U-bolt torque values.
Periodically:
Check the condition of spring leaves for
evidence of fatigue, bending, or breakage.
Check the condition of suspension
mounting brackets and bushings.
Ensure that suspension mounts (such as
brackets, bushings, fasteners) are tight.
Ensure that torque rod mounting
fasteners are tight.
Check U-bolts as follows:
5.1. After the chassis has been operating
under load for 1 600 km (1,000 mi)
or six months, whichever comes first,
the U-bolt nuts must be torqued
again.
5.2. Thereafter, the U-bolt nuts must be
torqued every 58 000 km
(36,000 mi). Torque interval may be
lowered to 40 000 km (25,000 mi)
to synchronize with oil change
interval.
Front Suspension
The front suspension should be regularly
inspected for loose, worn, or broken
components. Front suspensions/axles should
be checked periodically for proper alignment
to promote maximum tire life.
Rear Suspension
The rear suspension should be regularly
inspected for loose, worn, or broken
components. Rear suspensions/axles should
be checked periodically for proper alignment
to promote maximum tire life.
Rear Air Suspension
On vehicles equipped with the optional air
suspension, the air suspension components,
including air bags, height control valves, air
lines, and fittings should be inspected for
wear, damage, and audible air leaks.
The use of an air dryer does not eliminate
the need to periodically drain the air tank.
Located behind the passenger end of the
front bumper, the air dryer removes
humidity (water), air compressor oil, and dirt
from the incoming compressed air, which
protects the air system against deterioration
and restriction. The air dryer has a desiccant
cartridge and a filter, which is serviced as an
assembly. Moisture from the air collects on
the desiccant and is automatically
discharged. See Air Suspension 0 221 for
tank draining instructions.
Life and performance of the air dryer
depends on usage, air humidity levels,
environmental temperatures, air compressor
oil control, and desiccant quantity. Regularly
check the desiccant, purge valve, and air
dryer heater performance.
Desiccant Filter
Open the reservoir drain valves and check
for the presence of water. A small amount
of water due to condensation is normal.
If the wet, primary, or secondary tanks are
collecting an abnormally high amount of
water between regular air tank drain
intervals, replace the air dryer desiccant.