Do not remove the pressure cap from a hot engine. Wait until
the coolant temperature is below 120°F (50°C) before
removing pressure cap. Heated coolant spray or steam can
planned maintenance charts define checks to be completed
at a calendar interval. Coolant, lubricating oil and coolant
levels can be at normal levels, but can be contaminated
(Figure 2). When performing normal maintenance inspections
look for the following:
Restriction Indicator – Indicates when air restriction
to intake is greater than manufacturer specifications. Red
in color means change air filter (scheduled or not). Generally
indictor located on air filter housing. Can be reset after
Fuel Water Separator – This filter separates water
from fuel contaminated with water. Water is routed to bottom
bowl and can drain via valve. This can indicate main fuel
source supply is contaminated.
Water Indicating Paste – Used to test main fuel supply.
Spread on tank level stick. Pink in color with no water.
Turns red when fuel is contaminated with water. Generally
water at the lower section of tank.
Oil in Coolant – Oil floating on the coolant when
cooling system is at ambient temperature. Can appear milky
after engine operation. Engine lubricating oil leak into
cooling system. Can be cylinder head gasket, defective engine
block or cylinder head. Defect is where oil pressure is
higher than coolant pressure.
Coolant in Oil – Oil has milky color on dipstick.
Coolant leak into engine lubricating oil. Can be cylinder
head gasket, defective engine block or cylinder head. Defect
is where coolant pressure is higher than oil pressure.