
96 SEBU8219-01
Maintenance Section
Cooling System Water Temperature Regulator - Replace
3. Add tap water to
the mixing bottle in order to bring
the level up to the “10 ml” mark. Place the cap on
the bottle and shake the bottle.
4. Add 2 to 3 drops of the “NITRITE INDICATOR
SOLUTION B” to the mixing bottle. Move the bottle
in a circular
motion in order to mix the solution.
5. Add 1 drop of “NITRITE TEST SOLUTION A” to
the mixing bo
ttle. Move the bottle in a circular
motion in order to mix the solution.
6. Repeat 5 unti
l the solution changes color from red
to light gray, green, or blue. Record the number of
drops of “NITRITE TEST SOLUTION A” that were
required to c
ause the color change.
7. UseTable13tointerprettheresults.
Table 13
Number of
Drops
Concentration
of SCA
Maintenance
Required
Less than 25 Less than the
recommended
concentration of
SCA
Add SCA.
Retest the
coolant.
25 to 30 The
recommended
concentration of
SCA
None
More than 30 More than the
recommended
concentration of
SCA
Remove the
coolant.
Replace with
water only
Retest the
coolant.
Add th e SCA, If Necessary
Pressurized System: Hot coolant can cause seri-
ous burns. To open the cooling system filler cap,
stop the engine a nd wait until the cooling system
components are cool. Loosen the cooling system
pressure cap slowly in order to relieve the pres-
sure.
1. Remove the cooling system filler cap slowly.
Note: Always dispose of fluids according to local
regulations.
2. If necessary, drain some coolant in order to allow
spacefortheadditionoftheSCA.
NOTICE
Excessive supp
lemental coolant additive concentra-
tion can form deposits on the higher temperature sur-
faces of the cooling system, reducing the engine’s
heat transfer
characteristics. Reduced heat transfer
could cause cracking of the cylinder head and other
high temperature components.
Excessive supplemental coolant additive concentra-
tion could also result in blockage of the heat exchang-
er, overheat
ing, and/or accelerated wear of the water
pump seal.
Do not exceed
the recommended amount of supple-
mental coolant additive concentration.
3. Add the proper amount of SCA. For the
proper amoun
t of SCA, refer to this Operation
and Maintenance Manual, “Refill Capacities
and Recommendations” topic. The proper
concentrat
ion of SCA depends on the type of
coolant that is used. For the proper concentration
of SCA, refer to the Operation and Maintenance
Manual, “R
efill Capacities and Recommendations”
topic or consult your Caterpillar dealer..
4. Clean the c
ooling system filler cap. Install the
cooling system filler cap.
i02623972
Cooling System Water
Temperatur e Regu lato r -
Replace
SMCS Code: 1355-510
Replace the water temperature regulator before
the water temperature regulator fails. This is a
recommended preventive maintenance practice.
Replacing the water temperature regulator reduces
the chances for unscheduled downtime.
A water temperature regulator that fails in a
partially opened position can cause overheating or
overcooling of the engine.
A water temperature regulator that fails in the closed
position can cause excessive overheating. Excessive
overheating could result in cracking of the cylinder
head or piston seizure problems.