PS Magazine - TB 43-PS-587
PS, The Preventative Maintenance Monthly
ISSUE 587
OCTOBER 2001
PS 587
OCT 01
25
621B Scraper…
O
ne loose bolt on an earthmover’s roadwheels
could leave you with no visible means of transport.
That one loose bolt puts more stress on the other
bolts and that can make them loose, too. Then the
wheel begins to wobble, wallowing out the stud
holes and ruining the roadwheel.
Enough wobble and wallow and the wheel
breaks off.
So before you head out, kneel down and rub
your finger against the washers behind the road-
wheel nuts. A washer that moves freely is an indi-
cation the nut is working itself loose.
Tighten bolts if you can and report ‘em whether
you can or not.
NO STEERING WHEN DOZING!
R
ead and heed the words on Page 2-69 of
TM 5-2350-262-10, operators.
Never
steer
the ACE during dozing operations! Turning
the wheel while dozing puts so much stress
on the track that it can be thrown. Thrown
track can crack road wheels, bend road
arms and rip actuators from the hull.
And during other operations, forget sharp
turns. You can throw a track that way, too.
A
fter the day’s run, operators, you know to open the manual drain cocks on the
621B scraper’s front air tanks near the cab step (curbside).
Opening those drain cocks allows condensation to drain out of the scraper’s air brake
system. Condensation leads to corrosion and causes slow stops and brake failure.
So don’t forget to also open the drain
cock on the rear air tank, behind the
scraper’s bowl. Because of its location, this
tank is usually missed.
Finish the job by making sure all drain
cocks are closed. Otherwise your scraper
can’t build up the air pressure it needs to
release its brakes.
T
wo grease fittings that often get missed during scraper services are the ones that
lube the fan bearing and fan belt tightener. Both fittings are hard to find unless you
reach in—behind the engine's fan blades—and find them.
Without lube, the fan clutch pulley's bearing
can seize up.
Then the blades stop turning freely,
causing the engine and transmission to overheat.
The fan belt tightener puts the right amount of
tension on your scraper's fan belts. Without lube,
its bearing will also seize up. That means the fan
belts come loose. They'll slide or get ripped off
the pulley—causing the engine and transmission
to overheat. Your construction operations come
to a screeching halt.
These two fittings are next to each other. Lube
each fitting every month or 250 service hours.
A washer that moves means
nut is working loose
Each month,
lube fan
bearing and
fan belt
tightener
Drain
rear air
tank, too
follow the
word in TM
5-2350-262-10!
Never
steer
during dozing
operations!
Hey,
bub!
you
forgot
to lube
my fan
fittings!
M9 ACE…
587. 24-25 (C)
9/3/01
7:11 PM
Page 1
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