Tire Rim Maintenance

Proper preventive maintenance of rims and necessary hardware is of absolute importance to good tire service. Earthmover rims are submitted to extremely high stresses due to high inflation pressures, torque loads, steering and braking force, shock loads, and the applied load of the vehicle. Therefore, rims must be strong and durable, but like any other components, they have service life limits. Most rim assembly failures occur in the form of fatigue cracks in the rim base or flanges.

1. Cleaning and Inspecting -- Rim bases and rim parts should be thoroughly cleaned
-- especially the O-ring and gutter lock ring grooves Ä and cracks carefully
inspected before they are placed in service. Two methods of cleaning rims are:
Brushing -- hand wire brush or wire wheel on a flexible shaft grinder
Sandblasting -- commercially available sandblasting unit

Both methods achieve the desired results with an advantage to the sandblasting
operation in that all rust scale and foreign matter are removed down to bare metal.
Once rim parts have been cleaned, they can be inspected for stress cracks, broken
welds or other damage. If the rim appears sound, it should be painted with rust
preventive paint or coated with a rust inhibitor and prepared for service.

2. Storage -- Rims should be stored in a dry area to prevent rust or corrosion. Lock
rings and flanges should be separated to allow easy identification and matching of
correct parts in the final assembly. Rim parts and wheels should always be
properly identified by size, type, and manufacturer.
Always use a new O-ring, correctly matched to the rim assembly, when mounting
a tire. Used 0-rings should be immediately cut and discarded.

Valves and Their Maintenance

1. Large Bore and Super Large Bore Valves -- The difference in size of mining
tires requires different amounts of air volume to provide proper inflation. The
Large Bore Valve is standard for most tires, but increased inflation and deflation
time of the giant tires requires a faster, more efficient system. This has brought
about development of the Super Large Bore Valve inflating system. Comparative
tests reveal that deflation time is decreased by 75 percent and inflation time
reduced by more than 50 percent. The system uses adapters that allow pressures to
be checked with standard large bore gauges.

2. Valve Maintenance -- All valve hardware should be inspected during routine
preventive maintenance checks. Some basic suggestions:
a. Always check stems and extensions to be sure they are tight and properly
secured.
b. Check valve cores and remove if plugged or leaking.
c. Always replace valve caps to keep dirt or water from damaging the core.
d. Release of a small quantity of air will clean stem and core assembly and
keep foreign matter from fouling the gauges.