Tennant 275 Series II, Operator'S Manual

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MAINTENANCE
3-20
275 SERIES II MM190 (12---89)
C. Retainer
The engine is equipped with a 180
_
F (82
_
C)
thermostat. Normal engine temperature is 200
_
F
(93
_
C). Temperatures up to 220
_
F (104
_
C) are
allowable. Temperatures over 220
_
F (104
_
C)
indicate a problem exists.
A pressure cap is used on the radiator to prevent
overflow loss of water during normal operation. The
spring-loaded valve in the cap closes the outlet to
the overflow pipe of the radiator and thus seals the
system. Pressure developing within the system
raises the boiling point of the coolant and allows
higher temperatures without overflow loss from
boiling. The pressure valve opens at 7 psi (50 kPa),
allowing steam and water to pass out the overflow
pipe.
WARNING: Hot engine coolant. Scalding
can result. Do not open radiator cap or
service cooling system until radiator and engine
is cool to the touch.
ATTENTION! Never pour cold water or cold
antifreeze into the radiator of an overheated
engine. Allow the engine to cool to avoid cracking
the cylinder head or block. Keep the engine
running while adding water.
AIR INTAKE SYSTEM
The importance of maintaining an air filter cannot be
overemphasized. Dirt ingested through improperly
installed, improperly serviced, or inadequate air filter
elements wears out more engines than long hours of
operation. Even a small amount of dirt will wear out a
set of piston rings in just a few hours. Operating with
a clogged air filter element also causes the fuel
mixture to be richer, which can lead to formation of
harmful sludge deposits in the engine. Always cover
the air intake when the air filter is removed for
servicing. Do not neglect servicing the air filter. Use
only approved replacement parts. Keep all other air
intake components secure and in good condition to
prevent entrance of unfiltered air.
Overmaintenance can cause more damage than
good. Removing the air filter element more often
than is needed allows contaminants to enter the
engine unnecessarily. Clean or replace the air filter
element only when the restriction indicator indicates
excessive restriction in the system.
AIR FILTER RESTRICTION INDICATOR
The air filter restriction indicator signals when to
clean or replace the air filter element. Check the
restriction indicator daily. The yellow indicator
gradually becomes visible as the air filter element
loads with dirt.
Do not clean or replace the air filter element until the
yellow indicator reaches the top of the service
indicator and reads 20 in (500 mm). The indicator
may return to the “no restriction” position when the
engine is shut off. It will return to the “visible”
position when the engine is started.
Clean or replace the filter element when the yellow
indicator reads 20 in (500 mm). After cleaning or
replacing the air filter element, reset the service
indicator by pushing the “reset” button on the end of
the indicator.
A
B
C
02172
AIR FILTER RESTRICTION INDICATOR
A. Restriction Indicator
B. Indicator Window
C. Indicator Reset Button