
102 SEBU8213-04
Maintenance Section
Cooling System Water Temperature Regulator - Clean/Replace
Note: Always di
scard drained fluids according to
local regulations.
Obtain the sam
ple of the coolant as close as possible
to the recommended sampling interval. In order
to receive the full effect of S·O·S analysis, you
must establi
sh a consistent trend of data. In order
to establish a pertinent history of data, perform
consistent samplings that are evenly spaced.
Supplies fo
r collecting samples can be obtained from
your Caterpillar dealer.
Use the foll
owing guidelines for proper sampling of
the coolant:
•
Complete t
he information on the label for the
sampling bottle before you begin to take the
samples.
•
Keep the unused sampling bottles stored in plastic
bags.
•
Obtain coolant samples directly from the coolant
sample port. You should not obtain the samples
from any o
ther location.
•
Keep the lids on empty sampling bottles until you
are read
y to collect the sample.
•
Place the sample in the mailing tube immediately
after ob
taining the sample in order to avoid
contamination.
•
Never c
ollect samples from expansion bottles.
•
Never collect samples from the drain for a system.
4. Maintain the coola nt level between minimum
mark (B) and maximum mark (A). Add coolant, if
neces
sary.
5. Install cooling system pressure cap (1) onto
expa
nsion tank (2). Close the access panel on top
of the engine compartment. Close the left engine
access door.
Submit the sample for Level 2 analysis.
For
additional information about coolant analysis, see
Special Publication, SEBU6250, “Caterpillar Machine
Fluids Recommendations” or consult your Caterpillar
dea
ler.
i02538687
Cooling Sys tem Water
Temp eratu re R
egulator -
Clean/Replace
SMCS Code: 13
55; 1393
Replace the thermostat on a regular basis in order to
reduce the c
hance of unscheduled downtime and of
problems with the cooling system.
A new thermo
stat should be installed after the cooling
system has been cleaned. Install the thermostat
while the cooling system is completely drained or
while the c
ooling system coolant is drained to a level
that is below the thermostat housing.
NOTICE
Failure t
o replace the engine's thermostat on a regu-
larly scheduled basis could cause severe engine dam-
age.
Note: If you are only installing a new thermostat,
drain the cooling system coolant to a level that is
below th
e thermostat housing.
1. Loosenthehoseclampandremovethehosefrom
the elb
ow. Disconnect the hose assembly from
the thermostat housing assembly.
2. Remove
the bolts from the elbow. Remove the
elbow and the thermostat housing assembly.
3. Remov
e the thermostat and the O-ring seal from
the thermostat housing.
NOTICE
Ause
d thermostat can be installed if the thermostat
conforms to test specifications, and the thermostat is
not damaged. Do not install a used thermostat that has
exc
essive buildup or deposits.
NOTICE
Si
nce Caterpillar engines incorporate a shunt design
cooling system, it is mandatory to always operate the
engine with a thermostat.
Depending on load, failure to operate with a thermo-
stat could result in either an overheating or an over-
c
ooling condition.
NOTICE
If the thermostat is installed incorrectly, it will cause
theenginetooverheat.