PS Magazine - TB 43-PS-572
PS, The Preventative Maintenance Monthly
ISSUE 572
JULY 2000
PS 572
9
JUL 00
PS 572
8
JUL 00
perators, your dump truck’s hydrau-
lic cylinders leak. Some leak just a dab,
others a bit more. But don’t call your
mechanic because the cylinders are
supposed to leak.
The single ram cylinders on all
M929/M930 dump trucks seep just
ot a differential fuel pressure gauge that reads zero or less when you’re
pumping fuel from an M978 HEMTT tanker? That gauge is bad and needs to be
replaced!
Replace it with a new style of pressure gauge, NSN 6685-01-362-4272, that
starts at .5 psi. It’s more reliable than the old-style gauge that started at 5 psi.
You can better keep up with the amount of dirt in the fuel filters.
As the filters get dirty, the pressure differential should slowly increase. That’s
normal. A differential of more than 15 psi indicates dirty filters that need to be
replaced.
If an old gauge still works well, use it. But at the first sign of poor perfor-
mance, have your mechanic replace it. A reading of less than 0 is one sign of
poor performance (or a burst filter). Another is a sudden decrease or return to 0
pressure during operation.
The gauge is Item 12 in Fig 436 of TM 9-2320-279-24P-2.
HEMTT Tankers . . .
Dump Trucks . . .
Hoist cylinder
seeps to lube
seal and coat
cylinder
enough to keep the rod coated with oil
and the seal wet. The oil protects the
rod from the elements and corrosion.
Telescoping hydraulic cylinders—
like the hoist cylinders on M917 and
F5070 dump trucks—have seals at each
segment of the cylinder. Each seal seeps
a bit to lube the seal and coat the cyl-
inder. The seepage adds up—as much
as a quart a day. But this type of leak-
age does not make your truck NMC.
If the hoist cylinder will raise the
empty dump body, your truck’s OK.
But keep an eye on the fluid level. If
it takes more than a quart a day to
refill the reservoir, get your mechanic
to look things over.
Old gauge
New gauge
the hydraulic
cylinder on this
dumper is
leaking
.
that makes it
nmc
,
right?
not
necessarily.
i used to
work hard
-
-now i
hardly work
!
PS 572
9
JUL 00
PS 572
8
JUL 00
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