Inspection; Aluminum Wheel Anti-Corrosion Protection (Without Dura-Bright) - PREVOST H3-41 Maintenance Manual

TORQUE (aluminum & steel wheels):
450-500 lb-ft (610-678 Nm)
CAUTION
Insufficient mounting-torque can result in
damage to parts. Excessive mounting torque
can cause studs to break and the wheel to
crack in stud hole area.
NOTE
On dual wheel assemblies, position the wheels
with the tire valves 180º apart in order to have
access to both the inner and outer valves.

4.5 INSPECTION

1. Loosen a hex stud nut three turns (Figure 5);
2. Retighten the hex stud nut.
TORQUE: 450-500 lb-ft (610-678 Nm)
Repeat for each of the 10 "hex stud nuts"
according to the tightening sequence in figure 3.
CAUTION
The actual length of thread engagement
present in an assembled wheel cannot always
be determined by
measurement of a tightened assembly. The
relationship of the wheel cap nut seat to the
end of the stud may vary. If there is any doubt
that enough thread engagement is present,
the number of engaged threads may be
counted. Tighten all nuts in the regular
manner, then loosen one to hand-tightness.
The number of turns to disengage a 1-1/8-inch
nut should be at least five full turns.
At least seven full turns should be required to
disengage a ¾-inch nut or a M22 nut. Ideally,
when torqued to the proper load, the stud
should be flush with the face of the nut. The
face of the nut may be recessed in nuts that
are taller for improved wrenching. With most of
the nuts in present use, a few unengaged
threads at the outer end will cause no problem
provided at least 5-7 full turns are required to
disengage the nut depending on thread size.
visual inspection of
SECTION 13: WHEELS, HUBS AND TIRES
5. ALUMINUM WHEEL ANTI-CORROSION
PROTECTION (WITHOUT DURA-BRIGHT)
Clean wheels often by means of a high pressure
water jet. Cleaning may be accelerated with mild
soap. Do not use concentrated alkaline cleaning
products.
When tire is removed, clean and inspect wheel
thoroughly. Remove dirt and corrosion on rim by
means of a wire brush. Do not use a wire brush
on the outer surface of the wheel.
The following measures should be taken to
maintain original appearance of the aluminum
wheels:
1. Remove any tar from wheel surface with a
good quality tar remover.
2. Spray Alcoa Cleaner (Prevost #683529)
evenly on cool outer surface of wheel. Let
work 15-20 minutes (keep wet by spraying
more Cleaner if necessary).
3. Rinse thoroughly with clean water and let air
dry. Heavy oxidation may require a repeat
application of cleaner.
4. Apply Alcoa
sparingly to a small area using a clean, soft
cloth. Work polish into surface as you would
a rubbing compound.
5. Buff, turning cloth frequently, until surface is
clean and shiny. Let air dry. Use power
buffer to improve ease of use and gloss
uniformity.
6. On completely dry, clean and polished
surface, generously apply Alcoa sealant
(Prevost #683527). Rinse thoroughly with
water while surface is still wet in appearance
(have water source ready as the dry time is
very short, usually less than 2 minutes).
7. For best results, finish by wiping the surface
with a clean rag to remove excess water,
then allow surface to dry.
CAUTION
Dura-Bright is a special surface treatment that
does not require polishing. Do not use
abrasives, abrasive
scouring pads or strong chemicals on Dura-
Bright wheels.
Do not use Alcoa Aluminum care system on
Dura-Bright wheels, clean regularly with high
pressure water jet and mild detergent.
PA1621 Maintenance Manual All Series | January 2017
Polish (Prevost #683528)
brushes steel
9
wool