H04025 Oiling and Charging Procedures H4-3
OILING AND CHARGING PROCEDURE
GENERAL
These procedures cover the Oiling and Charging of
HYDRAIR
®
II suspensions on Komatsu Electric Drive
Dump Trucks.
Suspensions which have been properly charged will
provide improved handling and ride characteristics
while also extending the fatigue life of the truck frame
and improving tire wear.
NOTE: Inflation pressures and exposed piston
lengths are calculated for a normal truck gross
vehicle weight (GVW). Additions to truck weight by
adding body liners, tailgates, water tanks, etc. should
be considered part of the payload. Keeping the truck
GVW within the specification shown on the Grade/
Speed Retard chart in the operator cab will extend
the service life of the truck main frame and allow the
HYDRAIR
®
II suspensions to produce a comfortable
ride.
All HYDRAIR
®
II suspensions are charged with
compressed nitrogen gas with sufficient pres-
sure to cause injury and/or damage if improperly
handled. Follow all safety instructions, cautions,
and warnings provided in the following proce-
dures to prevent any accidents during Oiling and
Charging.
Proper charging of HYDRAIR
®
II suspensions
requires that three basic conditions be established in
the following order:
1. Oil level must be correct.
2. Suspension piston rod extension for nitrogen
charging must be correct.
3. Nitrogen charge pressure must be correct.
For best results, HYDRAIR
®
II suspensions should
be charged in pairs (fronts together and rears
together). If rears are to be charged, the fronts
should be charged first.
NOTE: For longer life of suspension components, a
Friction Modifier should be added to the suspension
oil. See Specifications Chart, Figure 4-5 at the end of
this chapter.
NOTE: Set up dimensions specified in the charts
must be maintained during oiling and charging
procedures. However, after the truck has been
operated, these dimensions may vary.
EQUIPMENT LIST
•HYDRAIR
®
Charging Kit
• Jacks and/or Overhead Crane
• Support Blocks (Front and Rear) for:
Oiling Height Dimensions
Nitrogen Charging Height Dimensions
•HYDRAIR
®
Oil (See Specifications Chart)
• Friction Modifier (See Specifications Chart)
• Dry Nitrogen (See Specifications Chart)