
92 SEBU8088-06
Maintenance Section
Cooling System Water Temperature Regulator - Replace
i02623972
Cooling System Water
Temperature R
egula tor -
Replace
SMCS Code: 135
5-510
Replace the water temperature regulator before
the water tem
perature regulator fails. This is a
recommended preventive maintenance practice.
Replacing the water temperature regulator reduces
the chances f
or unscheduled downtime.
A water temperature regulator that fails in a
partially op
ened position can cause overheating or
overcooling of the engine.
Awatertempe
rature regulator that fails in the closed
position can cause excessive overheating. Excessive
overheating could result in cracking of the cylinder
head or pist
on seizure problems.
A water temperature regulator that fails in the open
position wi
ll cause the engine operating temperature
to be too low during partial load operation. Low
engine operating temperatures during partial loads
could caus
e an excessive carbon buildup inside the
cylinders. This excessive carbon buildup could result
in an accelerated wear of the piston rings and wear
of the cyli
nder liner.
NOTICE
Failure to replace your water temperature regulator
on a regul
arly scheduled basis could cause severe
engine damage.
Caterpil
lar engines incorporate a shunt design cooling
system and require operating the engine with a water
temperature regulator installed.
If the water temperature regulator is installed incor-
rectly, the engine may overheat, causing cylinder head
damage. E
nsure that the new water temperature reg-
ulator is installed in the original position. Ensure that
the water temperature regulator vent hole is open.
Do not use liquid gasket material on the gasket or
cylinder head surface.
Refer to two articles in the Disassembly and
Assembly Manual, “Water Temperature Regulators
- Remove
and Water Temperature Regulators -
Install” for the replacement procedure of the water
temperature regulator, or consult your Caterpillar
dealer
.
Note: If only th
e water temperature regulators are
replaced, drain the coolant from the cooling system to
a level that is below the water temperature regulator
housing.
i02933380
Crankshaft Vibration Dampe r
-Inspect
SMCS Code: 1205-040
Damage to the crankshaft vibration damper or failure
of the crankshaft vibration damper can increase
torsional vibrations. This can result in damage to
the crankshaft and to other engine components. A
damper that is damaged can cause excessive gear
train noise at variable points in the speed range.
The damper is mounted to the crankshaft which is
located behind the belt guard on the front of the
engine.
Visconic Damper
The visconic damper has a weight that is located
inside a fluid filled case. The weight moves in the
case in order to limit torsional vibration.
Inspect the damper for evidence of fluid leaks. If
a fluid leak is found, determine the type of fluid.
The fl uid in the damper is silicone. Silicone has
the following characteristics: transparent, viscous,
smooth, and adhering.
If the fluid leak is oil, inspect the crankshaft seals for
leaks. If a leak is observed, replace the crankshaft
seals.
Inspect the damper and repair or replace the damper
for any of the following reasons:
•
The damper is dented, cracked, or leaking.
•
The paint on the damper is discolored from heat.
•
The engine has had a failure because of a broken
crankshaft.
•
Analysis of the oil has revealed that the front main
bearing is badly worn.
•
There is a large amount of gear train wear that is
not caused by a lack of oil.
Refer to the Disassembly and Assembly Manual,
“Vibration Damper and Pulley - Remove and Install”
or consult your Caterpillar dealer for information
about damper replacement.