CUMMINS NTA-855-L4 Maintenance And Operator's Manual
TECHNICAL MANUAL
MASHINESOFT.COM
09120146259
OPERATOR' S, UNIT, INTERMEDIATE
(DS) AND INTERMEDIATE (GS)
MAINTENANCE MANUAL
FOR
ENGINE, DIESEL,
CUMMINS MODEL NTA - 855 -L4
NSN 2815-01-216-0939
TM 5-2815-233-14
(Circle C) Copyright 1983
HEADQUARTERS, DEPARTMENT OF THE ARMY
Cummins Engine Company, Inc.
Used by Permission
25 JULY 1986
TM 5-2815-233-14
MASHINESOFT.COM
09120146259
TECHNICAL MANUAL HEADQUARTERS
DEPARTMENT OF THE ARMY
NO 5-2815-233-14 WASHINGTON, D. C., 25 July 1986
OPERATOR'S UNIT, INTERMEDIATE
(DS) AND INTERMEDIATE (GS)
MAINTENANCE MANUAL
ENGINE, DIESEL,
CUMMINS MODEL NTA-855-L4
NSN 2815-01-216-0939
NOTE:
This manual is printed in two parts as follows:
Part 1 consisting of Table of Contents, Operation and Maintenance instructions.
Part 2 consisting of a separate Table of Contents and Repair instructions.
REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any mistake or if you know of a way to
improve the procedures, please let us know. Mail your letter, DA Form 2028
(Recommended Changes to Publications and Blank Forms), or DA Form 2028-2 located
in the back of this manual direct to: Commander, U.S. Army Troop Support Command,
ATTN: AMSTR-MCTS, 4300 Goodfellow Boulevard, St. Louis, MO 63120-1798.
A reply will be furnished directly to you.
TABLE OF CONTECTS
Operating Instructions
Specifications and Torque
Prestarting Instructions........................................1-1
Starting the Engine..............................................1-3
Engine Warm-Up................................................1-6
Engine Speeds....................................................1-6
Engine Exhaust...................................................1-7
High Altitude Operation.......................................1-7
Engine Shutdown................................................1-7
Cold Weather Protection.....................................1-8
Industrial Fire Pump Engines..............................1-11
Maintenance Operations
Schedule.............................................................2-2
Check Sheet.......................................................2-3
A Checks - Daily.................................................2-7
A Checks - Weekly..............................................2-11
B Checks............................................................2-15
C Checks............................................................2-34
D Checks............................................................2-50
Seasonal Maintenance Checks...........................2-54
Lubricating Oil.....................................................3-1
Grease................................................................3-5
Fuel 011..............................................................3-6
Coolant...............................................................3-7
Torque Speclflcatlons..........................................3-8
Trouble-Shooting
Description..........................................................4-1
Chart...................................................................4-2
Index
Intro pg
Part I
MASHINESOFT.COM
09120146259
OPERATION AND MAINTENANCE
TM 5-2815-233-14
a
Operation and Maintenance Manual Cummins Diesel
MASHINESOFT.COM
09120146259
Engines
Agricultural
Construction
Industrial
Industiral Fire Pump
Logging
Mining
Railway
Generator
TM 5-2815-233-14
Copyright © 1980
Cummins Engine Company, Inc. Bulletin 3379052-09 Printed 10/80
b
Foreword
MASHINESOFT.COM
09120146259
This is an engine operation and maintenance manual, not a
repair manual. The design of Cummins Engines makes it
possible to replace worn or damaged parts with new or rebuilt
parts with a minimum of down time. Contact the nearest
Cummins Distributor for parts replacement as they are equipped
and have well informed, trained personnel to perform this
service. If your shop is properly equipped to perform either
maintenance, unit replacement and/or complete engine rebuild,
contact the nearest Cummins Distributors to obtain available
repair manuals and arrange for training of personnel.
For model identification of an engine, check the dataplate. The
letter and number code indicates breathing (naturally aspirated
except when letter "T" for turbocharged is present), cubic inch
displacement, application and maximum rated horsepower.
Examples:
TM 5-2815-233-14
NTA-855-370 V-903-320
N=4 valve head V=Type engine
T=Turbocharger 903=Cubic Inch
A=Aftercooled Displacement
370=Maximum rated 320=Maximum Rated
horsepower horsepower
Cummins Engine Company, Inc.
Columbus, Indiana, U.S.A.
c/(d Blank)
Operating
MASHINESOFT.COM
09120146259
Instructions
General-All Applications
New and Rebuilt Engines Break-In
Cummins engines are run-in on dynamometers before
being shipped from the factory and are ready to be put
to work in applications such as emergency fire trucks,
rail car applications and generator sets. In other
applications, the engine can be put to work, but the
operator has an opportunity to establish conditions for
optimum service life during initial 100 hours of service
by:
1. Operating as much as possible at three-quarter
throttle of load range.
2. Avoiding operation for long periods at engine
idle speeds, or at the maximum horsepower
levels in excess of five minutes.
3. Developing the habit of watching the engine
instruments closely during operation and letting
up on the throttle if the oil temperature reaches
200° F [121° C] or the coolant temperature
exceeds 200° F [93° F].
4. Operating with a power requirement that allows
acceleration to governed speed when conditions
require more power.
The engine operator must assume the responsibility of
engine care while the engine is being operated. There
are comparatively few rules which the operator must
observe to get the best service from a Cummins Diesel.
4. If the injector and valve or other adjustments
have been disturbed by any maintenance work,
check to be sure they have been properly
adjusted before starting the engine.
Priming the Lubricating System
Note: On turbocharged engines, remove the oil inlet
line from the turbocharger and prelubricate the bearing
by adding 2 to 3 oz. [50 to 60 cc] of clean lubricating oil.
Reconnect the oil supply line.
1. Fill the crankcase to the "L" (low) mark on the
dipstick. See Lubricating Oil Specifications,
Section 3.
2. Remove the plug from the lubricating oil
crossover passage on NH/NT-855 Engines, Fig.
1-1. Remove the plug from the head of the
lubricating oil filter housing on V Engines, Fig's.
1-2, 1-3, 1-4, 1-5 and 1-6. On KT/KTA-1150
Engines, remove the plug from the front of the
oil cooler housing, Fig. 1-7.
Operating Instructions
5. Checking the oil level every 8 to 10 hours during the
break-in period.
New or Rebuilt Engines
Pre-Starting Instructions - First Time
Priming The Fuel System
1. Fill the fuel filter with clean No. 2 diesel fuel oil
meeting the specifications outlined in Section 3.
2. Remove the fuel pump suction line and wet the
gear pump gears with clean lubricating oil.
3. Check and fill the fuel tanks.
1-1
Fig. 1-1 (OM1001L). Lubricating system priming point-
NT-855 C.I.D. Engine
Fig. 1-2 (OM1002L). Lubricating system priming point-
MASHINESOFT.COM
09120146259
VT-903 C.I.D. Engine
Operation and Maintenance
Construction and Industrial
Fig. 1-4 (K21902). Lubricating system priming point
KT(A)-2300 Engine
Fig. 1-5 (OM202). Lubricating system priming point -
KTA-3067 Engine
Fig. 1-3 (OM1003L). Lubricating system priming point--
V/VT-555 C.I.D. Engine
Caution: Do not prime the engine lubricating
system from the by-pass filter.
3. Connect a hand- or motor-driven priming pump
line from a source of clean lubricating oil to the
plug boss in the housing.
4. Prime until a 30 psi [207 kPa] minimum
pressure is obtained.
5. Crank the engine at least 15 seconds (with fuel
shut-off valve closed or disconnected to prevent
starting), while maintaining the external oil pressure at a minimum of 15 psi [103 kPa].
6. Remove the external oil supply and replace the
plug.
Warning: Clean the area of any lubricating oil
spilled while priming or filling the crankcase.
7. Fill the crankcase to the "H" (high) mark on the
dipstick with oil meeting specifications, listed in
Section 3. No change in oil viscosity or type is
needed for new or newly rebuilt engines.
A dipstick oil gauge is located on the side of the engine,
Fig. 1-8. The dipstick has an "H" (high) (1) and "L" (low)
(2) level mark to indicate lubricating oil supply. The
dipstick must be kept with the oil pan, or engine, with
which it was originally supplied. Cummins oil pans differ
in capacity with different type installations and oil pan
part numbers. Check the dipstick calibration. If in
doubt, your Cummins Distributor
1-2
Fig. 1-6 (V41816). Lubricating system priming point - V-
MASHINESOFT.COM
09120146259
1710 Engine
OPERATING INSTRUCTIONS
can verify that you have the proper oil pan and dip-stick
calibration.
Check Hydraulic Governor
Many engines used in stationary power applications are
equipped with hydraulic-governed fuel pumps which use
lubricating oil as an energy medium, same weight as
used in the engine. Oil level in the governor sump must
be at the full mark on the dipstick.
Note: Engine applications in a cold environment should
use a lighter weight oil in the governor sump.
Check Air Connections
Check the air connections to the compressor and the air
equipment, as used, and to the air cleaners and air
crossovers to assure that they all are secure and have
no damage.
Check Engine Coolant Supply
1. Remove the radiator or heat exchanger cap and
check the engine coolant supply. Add coolant
as needed.
2. Make a visual check for leaks and open the
water filter shut-off valves.
Starting the Engine
Starting requires that clean air and fuel be supplied to
the combustion chambers in the proper quantities at the
correct time.
Normal Starting Procedure
Fig. 1-7 (OM1004L). Lubricating system priming pointKT/KTA C.I.D. Engine
Warning: Before starting be sure that everyone is
clear of the engine and equipment.
If the fuel system is equipped with an overspeed stop,
push the "Reset" button before attempting to start the
engine.
1. On units equipped with an air activated prelube
device, open the air valve to activate the piston
in the prelube device which will lubricate all
moving parts in the engine.
Note: On engines equipped with an oil pressure safety
switch, hold the fuel by-pass switch in the "start" position until the engine oil pressure reaches 7 to 10 psi [48
to 69 kPa]; then, move it to the "run" position.
2. Set the throttle for idle speed and disengage the
driven unit.
Fig. 1-8 (OM1005L). Checking engine oil level
Operating Instructions
Caution: Protect the turbocharger during start-up
by not opening the throttle or accelerating above
1000
1-3
Operation and Maintenance
MASHINESOFT.COM
09120146259
Construction and Industrial
rpm until the idle speed oil pressure registers on
the gauge.
3. Open the manual fuel shut-down valve, if so
equipped. Fig. 1-9. Electric shut-down valves operate
as the switch is turned on. A manual override knob
provided on the forward end of the electric shut-down
valve allows the valve to be opened in case of an
electric power failure. To use, turn fully clockwise;
return it to the run position after an electric repair.
Fig. 1-9 (V21970). Using manual override knob
4. Pull the compression release (if so equipped)
and press the starter button or turn the switchkey to the "start" position. After three or four
Caution: To prevent permanent cranking motor
damage, do not crank the engine for more than 30
seconds continuously. If the engine does not fire
within the first 30 seconds, wait one to two minutes
before recranking.
5. At the initial start or after oil or filter changes
seconds of cranking, close the compression
release (if so equipped) and continue to crank
until the engine fires.
and after the engine has run for a few minutes,
shut it down and wait 15 minutes for the oil to
drain back into the pan. Check the engine oil
level again; add oil as necessary to bring the oil
level to the "H" mark on the dipstick. The drop
in oil level is due to absorption by the oil filters.
Never operate the engine with the oil level
below the low level mark or above the high level
mark.
Cold-Weather Starting
Note: A water jacket heater is recommended for stand-
by generator set applications installed in a cold climate
Preheater
The glow plug system supplies heat to the cylinders so
that compression temperatures are sufficient to ignite
the fuel.
To aid in starting the engine when the temperature is
50°F [10.0°C] or below, an intake air preheater is
available.
Preheater equipment consists of a hand-priming pump
to pump fuel into the intake manifold, and a switch to
turn on the glow plug which is electrically heated by the
battery. Fuel burns in the intake mani-fold and heats
the intake air.
Warning: Do not use vapor in conjunction with the
preheater. To do so could result in a fire. To use
the preheater for cold starting:
1. Set the throttle in idle position. Turn the glow
plug toggle switch to the "ON" position. The red
indicator light must be on.
2. After the red light has been on for 20 seconds,
start cranking the engine. As soon as the
engine begins rotating, operate the preheater
priming pump to maintain 80 to 100 psi [552 to
689 kPa] fuel pressure. Use of the primer
before the 20-second interval will wet the glow
plug and prevent heating.
3. If the engine does not start within 30 seconds,
stop cranking. Wait one or two minutes and
repeat the cranking operation.
4. After the engine starts, pump the primer slowly
to keep the engine idling smoothly. In cold
weather this may require 4 to 5 minutes or
longer. Do not accelerate the engine.
5. When the engine has warmed up so it does not
falter between primer strokes, stop pumping.
Close and lock the primer. Turn off the glow
plug toggle switch. (The red indicator light will
go out.)
6. If the engine gives no indication of starting
during the first three full strokes of the preheater
pump, touch-check the intake manifold for heat.
If there is no heat, check the electrical wiring. If
the wiring is all right, remove the 1/8 inch pipe
plug (1, Fig.1-10) from the manifold near the
glow plug and
1-4
Fig 1-10 (OM1006L). Glow plug inspection hole NT-855
MASHINESOFT.COM
09120146259
C.I.D. Engine
close the glow plug manual switch for 15
seconds and observe the glow plug through the
1/8 inch plug hole. The glow plug should be
white hot; if not, connect the wiring to a 6- to 12volt (as used) source and check the amperage;
it should be 30 to 32 (minimum). If the glow
plug is all right, check the manual switch and
resistor (if used) and replace if necessary.
TM 5-2815-233-14
Manually Operated Valve
The manually operated valve, illustrated in Fig. 1-11
includes the valve body assembly (6), clamp (2) and
nylon tube (3). The fuel cylinder (1), atomizer fitting (5)
and pull control (7) must be ordered separately.
Standard pull or throttle control cables may be used, to
actuate the manual valve, if desired.
Electrically Operated Valve
The electrically operated valve, Fig. 1-12, includes the
valve body (7), 90 degree elbow (5), clamp (2), push
button switch (6), and nylon tube (3). The thermostat is
mounted on the engine exhaust manifold and cuts out
the valve by sensing manifold heat when the engine is
running. See parts catalog for fuel cylinder (1) and fuel
atomizer fittings (4). These fittings must be ordered
separately, as required.
Note: The preheater priming pump, switches and
resistor are located at the instrument panel and are to
be checked during engine starting.
The cold starting aid, approved for use in Cummins
Engines, has been based upon starting aid capabilities
to -25° F [-32° C].
Caution: Do not attempt to use vapor compound
type starting aids near heat, open flame or on
engines equipped with a glow plug system.
Fig. 1-11 (OM1007L). Manually operated valve
Fig. 1-12(OM1008L). Electrically operated valve
Installation Recommendations
The atomizer fittings must be mounted in the engine air
intake manifold or inlet connection to provide an equal
distribution of starting fuel to each cylinder. The
atomizer holes are 180 degrees apart and must be
mounted so the spray is injected the "long way" of the
manifold. If incorrectly installed, the spray goes
crosswise of the manifold.
Recommended Starting Technique Using
Fleetguard Starting Aid
1. Set the throttle for idle.
2. Disengage the driven unit or make sure gears
are in neutral.
3. Open the manual fuel shut-down valve, or
electric
1-5
Operation and Maintenance
MASHINESOFT.COM
09120146259
Construction and Industrial
shut-down valve, whichever is used.
4. Engage the starter and while cranking, apply
metered amounts of starting fluid until the
engine idles smoothly.
Use of Starting Fluid Without Metering Equipment
1. Spray starting fluid into the air cleaner intake,
while a second man cranks the engine.
Warning: Never handle starting fluid near an open
flame. Never use it with a preheater or flame
thrower equipment. Do not breathe the fumes. Use
of too much will cause excessively high pressures
and detonation, or over speed the engine.
2. Starting aid fumes will be drawn into the air
intake manifold and the cold engine should start
without difficulty.
Waming: Fuel oil or volatile fuel cold starting aids
are not to be used in underground mine or tunnel
operations. If the engine is so equipped check with
the local U.S. Bureau of Mines Inspector for use of
the starting aid.
Note: Engines in many applications are applied at a
lower than maximum rated speed; check the serial
dataplate.
Power generator units are pre-set to operate at a
specific governed rpm.
Table 1-1: Engine Speeds (RPM)
Engine Maximum
Model Rated
All NH, NT, 855-R, 855-L 2100
All NH, NT 2300
V-903 2600
VT-903 2400
V-378, V-504, V-555 3000
V-378, V-504, V-555 3300
V-1710, V-1710-L 2100
KT-1150 2100
KTA-1150 2100
KT-2300 2100
KTA-2300 2100
KTA3067 2100
Engine Warm-Up
When the engine is started, it takes a while to get the
lubricating oil film re-established between shafts and
bearings and between pistons and liners. The most
favorable clearances between moving parts are
obtained only after all engine parts reach normal
operating temperature. Avoid seizing pistons in liners
and running dry shafts in dry bearings by bringing the
engine up to operating speed gradually as it warms up.
On some emergency equipment (such as fire pump
engines) warm-up may not be necessary due to the
equipment being housed inside a heated building. For
an engine starting with a parasitic load, such as a fire
pump, the coolant temperatures must be a mini-mum of
120°F [49°C].
Engine Speeds
All Cummins engines are equipped with governors to
prevent speeds in excess of the minimum or predetermined lower speed rating.
The governor has two functions: First, it provides the
fuel needed for idling when the throttle is in the idle
position. Second, it overrides the throttle and shuts off
the fuel if the engine rpm exceeds the maximum rated
speed.
Speeds listed in Table 1-1 are for engines rated at
maximum rpm and fuel rate.
Oil Temperature
The oil temperature gauge normally should read
between 180° F [82° C] and 225° F [107° C]. Under full
load conditions, an oil temperature of 240°F [116°C] for
a short period is not cause for alarm.
Caution: Any sudden increase in oil temperature
which is not caused by a load increase is a warning
of possible mechanical failure and should be
investigated at once.
During the warm-up period, apply the load gradually
until the oil temperature reaches 140° F [60° C]. While
the oil is cold it does not do a good job of lubricating.
Continuous operation or long periods of idle with oil
temperatures below 140 F [60C] may cause crank-case
dilution and acids in the lubricating oil which quickly
accelerate engine wear.
Water Temperature
A water temperature of 160° to 200° F [710 to 93° C] is
the best assurance that the working parts of the engine
have expanded evenly to the most favorable oil
clearances. Maximum engine coolant temperatures
should not exceed 200°F [93°C].
Keep the thermostats in the engine during summer and
winter, avoid long periods of idling, and take the
necessary steps to keep the water temperature up to a
1-6
TM 5-2815-233-14
MASHINESOFT.COM
09120146259
Table 1-2: Oil Pressure PSI [kPa] @ 225°F [1070C]
Engine Series Minimum @ Idle Speed Rated Speed
NH/NT 8 [55] 40/70 [276/483]
Big Cam 11 8 [55] 25/45 [172/310]
VT-350, V-903, VT-903 5 [34] 40/65 [276/448]
V/VT-378, V/VT-504, VNT-555 10 [69] 50/90 [345/620]
VNT/VTA-1710 15 [103] 50/90 [345/620]
KT/KTA-1150 15 [103] 45/70 [310/483]
KT/KTA-2300 @ 2100 RPM 15 [103] 45/70 [310/483]
KT/KTA-2300 @ 1500, 1800 or 1950 RPM 15 [103] 40/70 [276/483]
KT/KTA-3067 @ 2100 RPM 20 [138] 45/70 [310/483]
KT/KTA-3067 @ 1500 or 1800 RPM 15 [103] 40/70 [276/483]
minimum of 160°F [71°C]. If necessary in cold
weather, use radiator shutters or cover a part of the
radiator to prevent overcooling.
3. Engage the power take-off.
Oil Pressure
Normal engine oil pressures at 225°F [107°C] oil
temperature are listed in Table 1-2.
Note: Individual engines may vary from the above
normal pressures. Observe and record the pressure
when the engine is new to serve as a guide for an
indication of progressive engine condition. (High oil
pressure during start-up is not cause for alarm.) For
record purposes these readings are more accurate and
reliable when taken immediately after an oil change.
High Altitude Operation
Some engines, particularly naturally aspirated, lose
horsepower when they are operated at high altitude
because the air is too thin to burn as much fuel as at sea
level. This loss is about 3 percent for each 1000 ft
[304.8 m] of altitude above sea level for a naturally
aspirated engine. Operate the engine using a lower
power requirement at high altitude to prevent smoke and
over-fueling.
Power Take-Off Application With PT (type G)
VS Fuel Pump
The VS fuel pump governor lever is used to change the
standard governed speed of the engine from rated
speed to an intermediate power take-off speed. When
changing from the standard speed range to the power
take-off speed with the engine idling on stand-ard
throttle, operate as follows:
1. Place the VS speed control lever in the
operating position.
2. Lock the standard throttle in the full-open
position.
To return to standard throttle:
1. Disengage the power take-off.
2. Return the standard throttle to the idle position.
3. Lock the VS speed control lever in the
maximum speed position.
Engine Shut-Down
Idle Engine A Few Minutes Before Shut-Down
It is important to idle an engine 3 to 5 minutes before
shutting it down to allow the lubricating oil and water to
carry heat away from the combustion chamber,
bearings, shafts, etc. This is especially important with
turbocharged engines.
The turbocharger contains bearings and seals that are
subject to the high heat of combustion exhaust gases.
While the engine is running, this heat is carried away by
oil circulation, but if the engine is stopped sudden-ly, the
turbocharger temperature may rise as much as 100° F
[380 C]. The results of the extreme heat may be seized
bearings or loose oil seals.
Do Not Idle Engine for Excessively Long Periods
Long periods of idling are not good for an engine
because the combustion chamber temperatures drop so
low the fuel may not burn completely. This will cause
carbon to clog the injector spray holes and piston rings
and may result in stuck valves.
If the engine coolant temperature becomes too low,
1-7
raw fuel will wash the lubricating oil off the cylinder walls
MASHINESOFT.COM
09120146259
and dilute the crankcase oil so all moving parts of the
engine will suffer from poor lubrication. If the engine is
not being used, shut it down.
Turn Switch to "Off" Position to Shut Down the
Engine
The engine can be shut down completely by turning off
the switch on installations equipped with an electric
shut-down valve, or by turning the manual shut-down
valve knob. Turning off the switch which controls the
electric shut-down valve stops the engine unless the
override button on the shut-down valve has been locked
in the open position. If the manual override on the
electric shut-down valve is being used, turn the button
fully counterclockwise to stop the engine. Refer to
"Normal Starting Procedure". The valve cannot be
reopened by the switch until after the engine comes to a
complete stop, unless a rapid re-start valve is installed.
Caution: Never leave the switch key or the override
button in the valve open or in the run position when
the engine is not running. With overhead tanks this
would allow fuel to drain into the cylinders, causing
a hydraulic lock.
Operation and Maintenance
Construction and Industrial
Fig. 1-13 (OM1010L). Cooling system drain points-NT-
855 C.I.D. Engine
Stop Engine Immediately If Any Parts Fail
Practically all failures give some warning to the operator
before the parts fail and ruin the engine. Many engines
are saved because alert operators heed warning signs
(sudden drop in oil pressure, unusual noises, etc.) and
immediately shut down the engine.
Cold-Weather Protection
1. For cold-weather operation, use of permanenttype antifreeze with rust inhibitor additives is
recommended. See Section 3.
2. Drain the cylinder block and heads on all
engines by opening the petcocks and removing
the drain plugs as shown in Fig's. 1-13 to 1-19.
3. Immersion-type water and oil heaters are
If an air compressor (Fig. 1-20), heat exchanger
or other "water cooled" accessory is used, open
the petcock and drain. Failure to properly drain
the engine and accessories may cause serious
damage during freezing weather.
available for engines used in cold-weather
operations and to maintain temperatures to
permit the engine to operate at full load at startup.
Fig. 1-14 (OM1012L). Cooling system drain points (oil
cooler side) VT-903 C.I.D. Engine
Fig. 1-15 (OM1013L). Cooling system drain points (left
bank side) VN/VT-555 C.I.D. Engine
1-8
TM 5-2815-233-14
MASHINESOFT.COM
09120146259
Fig. 1-16, (V40033). Coolant drain point - V/VT-1710
Engine
Fig 1-17,(OM1009L). Cooling system drain points-
KT/KTA-1150 C.I.D. Engine
Fig. 1-18, (K21903). Coolant drain point - KT(A)-2300
Engine
Fig. 1-19, (OM203.). Coolant drain point - KTA-3067
Engine
Fig. 1-20, (K21904). Two cylinder air compressor
coolant drain
Engine Operation in Cold Weather
Satisfactory performance of a diesel engine operating in
low ambient temperature conditions requires
modification of the engine, surrounding equipment,
operating practices and maintenance procedures. The
colder the temperatures encountered the greater the
amount of modification required and yet with the
modifications applied, the engines must still be capable
of operation in warmer climates without extensive
changes. The following information is provided to
engine owners, operators and maintenance personnel
on how the modifications can be applied to get
satisfactory performance from their diesel engines.
There are three basic objectives to be accomplished:
1. Reasonable starting characteristics followed by
1-9
Operation and Maintenance
MASHINESOFT.COM
09120146259
Construction and Industrial
practical and dependable warm-up of the engine and
equipment.
2. A unit or installation which is as independent as
possible from external influences.
3. Modifications which maintain satisfactory operating
temperatures with a minimum increase in maintenance
of the equipment and accessories.
If satisfactory engine temperature is not maintained,
higher maintenance cost will result due to the increased
engine wear, poor performance and formation of
excessive carbon, varnish and other deposits. Special
provisions to overcome low temperatures are definitely
necessary, Whereas a change to warmer climate
normally requires only a minimum of revision. Most of
the accessories should be designed in such a way that
they can be disconnected so there is little effect on the
engine when they are not in use.
The two most commonly used terms associated with
preparation of equipment for low temperature operation
are "Winterization" and "Arctic Specifications"
Winterization of the engine and/or components so
starting and operation are possible in the lowest
temperature to 'be encountered requires:
1. Use of correct materials.
3. Protection from the low temperature air. The metal
temperature does not change, but the rate of heat
dissipation is affected.
4. Fuel of the proper grade for the lowest temperature.
5. Heating to be provided to increase the engine block
and component temperature to a minimum of -25° F
[-32° C] for starting in lower temperatures.
6. Proper external heating source available.
7. Electrical equipment capable of operating in the
lowest expected temperature.
Arctic specifications refer to the design material and
specifications of the components necessary for
satisfactory engine operation in extreme low
temperatures to -65° F [-54° C]. Contact Cummins
Engine Company, Inc., or the equipment manufacturer
to obtain the special items required.
Caution: "Anti-leak" antifreezes are not
recommended for use in Cummins Engines.
Although these antifreezes are chemically
compatible with DCA water treatment, the "antileak" agents may clog the coolant filters and render
them ineffective.
2. Proper lubrication, 'low temperature lubricating oils.
1-10
Industrial Fire Pump Engines
MASHINESOFT.COM
09120146259
Fire pump engines are built and applied under
conditions set down by agencies such as Underwriters
Laboratory; therefore, parts originally supplied must not
be deviated from without qualifying agency approval.
The following instructions are those special items
necessary to this application, and should be used in
conjunction with those previously stated.
Maintenance Instructions
10. Check the crankcase oil level and fill it to the high
mark.
11. Start the engine and adjust overspeed.
12. Remove ST-1224 and replace the original adapter.
Initial Start-Up Note: Contact operating personnel
responsible for fire protection system before starting.
Obtain approval to service or repair. After repair obtain
authorized signature of acceptance.
1. Remove the heat exchanger cap, check or fill the
engine coolant supply; open the water filter inlet and
outlet valves.
2. Prelubricate the engine with oil meeting
specifications MIL-L-46152 (API-CC/SC) viscosity
10W30. This includes removal of the turbocharger
oil inlet line on turbocharged engines to prelubricate
the housing by adding 2 to 3 oz [60 cc] of clean
engine lubricating oil.
3. Check the crankcase oil level and fill to the high
mark on the dipstick.
4. Remove the fuel pump solenoid lead and crank the
engine through both cranking cycles.
5. If the engine is equipped with a "Vernier throttle",
place it in the idle position; if not, place the MVS
throttle in the idle position. On turbocharged models
the delay cylinder line may be disconnected at the
block and the block opening plugged.
6. Reconnect the fuel solenoid lead and start the
engine; run it at idle speed.
7. Verify the lubricating oil pressure has been
established, normally in 6 to 8 seconds.
Note: Some automatic controllers require lubricating oil
pressure higher than the normal pressure at 600 rpm
idle. Increase the idle to 800 to 900 rpm if this condition
is encountered. All turbocharged engines should be set
to 800 to 900 rpm idle.
13. Clean the raw water strainer.
14. Start the engine and adjust operating speed.
15. Adjust the raw water pressure regulator.
16. Engine is now ready for normal operation.
Normal Operation
1. Daily or normal operation would include the
checking of fuel, lubrication oil, coolant and
correcting any leaks or unusual conditions as
required.
2. Check the coolant and oil heaters to assure at least
120° F [49° C] water temperature has been
maintained.
3. Manually start the engine using the prescribed
starting procedure.
4. Operate the engine the prescribed period of time or
5 minutes after stabilization of the coolant
temperature.
5. Shut the engine down using the normal test
shutdown procedures.
Fire Pump Engines -Overspeed
Switch Adjustment
(IF Engine Models)
The speed switches required for overspeed protection
on fire pump engines require high speed for the
overspeed adjustment. All engines are now being
shipped adjusted at the maximum overspeed. The
following overspeed adjustments are 20 percent above
the rated engine speed.
8. Continue to operate the engine for 3 to 5 minutes
and review all systems for leaks or unusual
conditions; correct as required.
9. Stop the engine and install ST-1224 Adapter.
An adapter, ST-1224 with 2:1 ratio, in speed switch
drive only, (1, Fig. 1-21) is available to drive the speed
switch at twice the engine speed. This tool when
1-11
Operation and Maintenance
MASHINESOFT.COM
09120146259
Construction and Industrial
installed in place of the existing adapter permits
adjustment to be made to the speed switch at slightly
over 1/2 engine and pump speed. This maintains a
pump speed well within its safe speed range while the
adjustments are being made.
Table 1-3: Engine Overspeeds
Engine Rated
Model Speed Overspeed
V-378F1 1750-2200 2100-2640
V-378F2 2400-3300 2880-3960
V-504-F1 1750-2200 2100-2640
V-504-F2 2400-3300 2880-3960
N-855 1460-2100 1750-2520
NT-855-F1 1750-2100 2100-2520
NT-855-F2 1750-2300 2100-2760
VT-1710-F 1750-2100 2100-2520
Adjustment Procedure
1. Remove the present tachometer drive adapter.
2. Install the service tool, ST-1224, in position of the
standard drive adapter. Connect the tachometer
and overspeed stop switch to the ST-1224 Tool.
a. On inline engine models, this. can be
accomplished by adjusting the Vernier throttle
control.
b. On Medium Duty V engines, the speed
adjustment must be made by adjusting the
governor idle and maximum speed screws. The
idle screw is housed in the front of the MVS
governor. The maximum speed screw is
mounted to the MVS governor by a bracket and
is on the left hand side of the fuel pump.
Engine slow down is accomplished by turning
the idle speed screw counterclockwise and'
turning the maximum speed screw in a
clockwise direction. To increase the engine
speed reverse the procedure.
5. Set the single element speed switch.
a. Remove the lockwire from setscrews on the side
of the switch. Loosen the three (3) setscrews.
b. Rotate the cover clockwise (this decreases trip
speed) until the switch actuates and stops the
engine.
Note: The overspeed stop switch cable must be
connected to the short adapter connection. (1, Fig. 1-
21).
3. Start the engine and warm to operating temperature.
4. Set the engine speed to one-half (1/2) the desired
engine shut-down speed as indicated by the
tachometer.
c. Secure the setscrews and replace the locking
wire.
d. On manual reset models, re-activate the switch
by pushing the reset button on top of the switch.
6. Set the dual element speed switches.
Caution: Do not break or remove the lockwire.
a. Remove the round head dust cover screw
marked 2 from the top of the switch. Fig. 1-22.
b. Insert a 1/16 inch Hex Allen wrench into the
adjusting screw located just below the surface of
the cover.
Fig. 1-21, (ST-1224). ST-1224 adapter
Fig. 1-22, (CGS27). Double speed switch
1-12
c. Turn counterclockwise to lower the engine shut-
MASHINESOFT.COM
09120146259
down speed. Turn clockwise to raise the engine
shut-down speed.
Caution: Do not turn the adjusting screw more than
three (3) revolutions in either direction from the
factory setting. Do not attempt to set the duel
element switch in the same manner as the single
element switch.
d. Replace the dust cover screw removed in "Step
a" above.
TM 5-2815-233-14
e. All overspeed switches must be manually reset,
reactivate the switch by pushing the reset button
on top of the switch.
7. Replace the service tool, ST-1224, with the original
drive adapter and reconnect the cables.
Note: If the stop crank adjustment is required do not
use the ST-1224 Adapter. Replace with a standard
adapter to effect the adjustment.
Fire Pump Engine Operating Speed Adjustment
All Cummins fire pump engines will be shipped adjusted
at the speeds in Table 1-4, unless prior approval has
been established for a specific speed.
Final operating speed adjustment should be made at the
time of the in-service inspection to obtain the required
fire pump operating speed.
This speed adjustment must be made with the Vernier
throttle in the full fuel position and the systems fire
pump operating at its rated condition. All speed ranges
of N-NT and V-12 models are available by adjusting the
VS high speed adjusting screw. Fig's. 1-23 and 1-24.
Table 1-4: Fire Pump Engine Operating Speed
Fuel Factory Maximum
Engine Pump Adjusted Operating
Model Code Speed Speed
V-378-F1 C-653 1750 2200
V-378-F2 C-651 2400 3300
V-504 F1 C-652 1750 2200
V-504 F2 C-650 2400 3300
N-855 8761 1750 2100
NT-855 Fl 8770 1750 2100
NT-855 F2 8771 1750 2300
VT-1710 F 8784 1750 2100
Fig. 1-23, (N11979). Adjusting engine speed
Fig. 1-24, (N11980). Governor adjusting screw
ment is made by loosening the 7/16 inch locking nut and
backing the screw out to increase the engine speed
through the full speed range.
The V-378 and V-504 F1 and F2 models require two
differently calibrated fuel pumps. One pump code
provides speeds between 1750 and 2300 rpm. A
different pump code is required for speeds between
2400 and 3300 rpm. The required speeds on these
models are similarly obtained by MVS adjustment within
the calibrated range as indicated above. It normally is
prohibited by UL and FM to change engine ratings by
changing fuel pumps on any models of fire pump
engines. In the event of fuel pump rebuild, the pump
must be calibrated to the original code and any
deviation would be a violation to the insurance
agencies approval.
This screw requires a 1/8 inch Allen wrench and adjust-
1-13
MASHINESOFT.COM
09120146259
1-14
Maintenance Instructions
MASHINESOFT.COM
09120146259
Maintenance is the key to lower operating costs. A
Maintenance diesel engine requires regularly scheduled maintenance
to keep it running efficiently.
Maintenance Schedule
Preventive maintenance is the easiest and least
expensive type of maintenance. It permits the
Maintenance Department to do the work at a convenient
time.
A Good Maintenance Schedule Depends On Engine
Application
Actual operating environment of the engine governs the
maintenance schedule. The suggested check sheet on
the following page indicates some checks have to be
performed more often under heavy dust or other special
conditions.
Using the Suggested Schedule Check Sheet
The maintenance schedule check sheet is designed as a
guide until adequate experience is obtained to establish
a schedule to meet a specific operation.
A detailed list of component checks is provided through
several check periods; also a suggested schedule basis
is given for hours of operation, or calendar of time.
A maintenance schedule should be established using
the check sheet as a guide; the result will be a
maintenance program to fit a specific operation.
The check sheet shown can be reproduced by any
printer. The person making each check can then
indicate directly on the sheet that the operation has
been completed. When a complete column (Under A,
B, C, etc.) of checks is indicated, the engine will be
ready for additional service until the next check is due.
Storage for Engines Out of Service
If an engine-remains out of service and its use is not
immediately forthcoming, special precautions should be
taken to prevent rust. Contact the nearest Cummins
Distributor or consult applicable Shop Manual for
information concerning engine storage procedure.
2-1
MASHINESOFT.COM
09120146259
2-2
MASHINESOFT.COM
09120146259
To prove that the Engine has been properly maintained retain records, such as work orders and receipts, showing that scheduled maintenance has
been performed. The maintenance record form on this page is for that purpose.
2-3
Operation and Maintenance
MASHINESOFT.COM
09120146259
Construction and Industrial
Scheduled Maintenance
Schedule I, Schedule II
The following maintenance schedules should be used to
establish maintenance practices for Cummins standby
(GS) or continuous duty (GC) generator sets.
Schedule I is used with standby applications. Many of
these installations are regulated by NFPA and/or local
codes (reference NFPA No. 76A).
Standby rated generator sets are for supplying electric
power in the event of normal utility power failure. No
overload capability is available for this rating. This
rating may be used for continuous service for as long as
the emergency may last. This rating conforms with the
BS 649:1958 overload rating and DIN "B" 6270.
Schedule II is used with continuous duty applications.
Continuous duty rated generator sets are for supplying
electric power in lieu of commercially purchased power.
Intermittent overloads up to the standby rating are
allowable. This rating may be used for continuous
service in commercial applications and it conforms with
BS 649:1958 and DIN "A" 6270 for generator set
applications.
Using The Suggested Schedule Check Sheet
Actual operating environment of the engine governs the
maintenance schedule. The-suggested check sheet on
the following page indicates some checks have to be
performed more often under heavy dust or other special
conditions.
The maintenance schedule check sheet is designed as a
guide until adequate experience is obtained to establish
a schedule to meet a specific operation.
A detailed list of component checks is provided through
several check periods; also a suggested schedule basis
is given for hours of operation, or calendar of time.
A maintenance schedule should be established using
the check sheet as a guide; the result will be a
maintenance program to fit a specific operation.
Cummins Standby Generator Sets
Cummins standby generator sets may be required to
start and come on line in 10 seconds or less.
These engines must be equipped with engine coolant
heaters capable of maintaining coolant temperature at a
minimum of 100°F [38° C].
Engines subject to ambient temperatures less than 2-4
70° F [21° C] must also be equipped with a lubricating
oil heater. When using a lubricating oil heater
immersed in oil, the maximum surface of heater in
contact with oil, should be less than 300° F [149° C] to
minimize formation of hard carbon on the heating
element.
Recommended wattage for the heaters when the unit is
in a protected area or in an enclosure are shown in
Bulletin No. 3379009, in Section 7 Miscellaneous.
Standby units should be operated once a week under a
minimum of 25% of rated KW load for at least thirty
minutes. During this test, the engine must reach normal
operating temperature.
Cummins Continuous Duty Generator Sets
Continuous duty generator sets may be equipped with a
cold starting aid. Maintenance procedures for these
devices can be found in the seasonal maintenance
section.
2-4
MASHINESOFT.COM
09120146259
2-5
MASHINESOFT.COM
09120146259
2-6
"A" Maintenance Checks-Daily
MASHINESOFT.COM
09120146259
Make a Daily Report of Engine Operation to the
Maintenance Department
The engine must be maintained in top mechanical
condition if the operator is to get optimum satisfaction
from its use. The maintenance department needs daily
running reports from the operator to make necessary
adjustments in the time allotted and to make provisions
for more extensive maintenance work as the reports
indicate the necessity.
Comparison and intelligent interpretation of the daily
report along with a practical follow-up action will
eliminate most failures and emergency repairs.
Maintenance Instructions
Fig. 2-1, (K21901). Checking engine oil level
Report to the Maintenance Department any of the
following conditions:
1. Low lubricating oil pressure.
2. Low power.
3. Abnormal water or oil temperature.
4. Unusual engine noise.
5. Excessive smoke.
6. Excessive use of coolant, fuel or lubricating oil.
7. Any fuel, coolant or lubricating oil leaks.
Check Engine
Check Engine Oil Level
Check Engine Coolant Level
Keep the cooling system filled to the operating level.
Check the coolant level daily or at each fuel fill point.
Investigate for causes of coolant loss. Check the
coolant level only when the system is cool.
Check Belts
Visually check belts for looseness. If there is evidence
of belt slippage adjust as follows: Using the appropriate
gauge, Fig's. 2-2 and 2-3, check.
Note: Some dipsticks have dual markings, with high
and low-level marks: static oil marks on one side,
engine running at low idle speed marks on opposite
side. Be sure to use the proper scale.
1. Check the oil level with the dipstick oil gauge
located on the engine. Fig. 2-1. For accurate readings,
the oil level should not be checked for approximately 15
minutes after the engine is shut-down.
Keep the dipstick with the oil pan with which it was
originally shipped. Keep the oil level as near the "H"
(high) mark as possible.
Caution: Never operate the engine with the oil level
below the "L" (low) mark or above the "H" (high) mark.
2. If necessary, add oil of the same quality and brand
as already in the engine. See Section 3.
Fig. 2-2, (OM1014L). Checking belt tension with a Krikit
gauge
2-7
Operation and Maintenance
MASHINESOFT.COM
09120146259
Construction and Industrial
Table 2-1: Belt Tension (Lbs.)
Belt New Belt* Minimum • Used Belt Installation Tension
Width Belt Tension Tension • If Below Min. Tension, Retention to
Inches Gauge (lb.) + 10 (lb.) (lb.) + 10
.380 ST-12748 140-150 60 100
.440 CAN-292 140-150 60 100
1/2 140-150 60 100
11/16 160-170 60 100
3/4 ST-1138 160-170 60 100
7/8 160-170 60 100
K-Sect.
5 Rib ST-1293 125-135 60 100
V-Ribbed
K-Sect
6, Rib- ST-1293 150-160 70 120
V-Ribbed
K;Sect
10 Rib NUA 250-260 140 200
V-Ribbed
* Used belts should be retensioned to values listed in this column.
Note: A belt is considered as used. if it has been in operation for a period of time of at least 5 minutes.
and/or adjust belts to the tension as indicated in Table 2-
1.
Inline Engine Water Pump Belts (No Idler)
1. Eccentric water pump adjustment.
a. Loosen the water pump clamp ring to allow the
pump body to turn.
b. Loosen the pump body by pulling up on the
belts. A sharp jerk may be required.
c. Insert a bar in the water pump body slots and
rotate the pump body counterclockwise to
tighten the belts.
Note: Do not adjust to final tension at this time.
Fig. 2-3, (OM1015L). Adjusting belt tension with ST-
1293
Note: When using the "Krikit" gauge the correct belt
tension reading for the belt tested must be read at the
point where the top of the black indicator arm crosses
the bottom numbered scale. Position the gauge in the
center of the belt between two pulleys. The flange at
the side of the gauge should be flat against the edge of
the belt.
d. Snug the clamp ring capscrew farthest from the
belts, on the exhaust side to 5 ft-lbs [7 N m].
e. Snug the two capscrews above and below the
first one to 5 ft-lbs [7 N m].
f. Finish tightening by alternating from side to side
in 5 ft-lbs [7 N.m] increments to a final torque of
12 to 15 ft-lbs [16 to 20 N m].
2-8
Maintenance Instructions
MASHINESOFT.COM
09120146259
g. Check the belt tension.
Final belt tension was not obtained by adjustment alone.
The water pump body was pulled straight by snugging
the capscrews in the order described, thus increasing
the belt tension to the final value.
2. Adjustable (split) pulley water pumps, V-903
Engines only.
a. Remove the capscrews joining the sheave(s) of
the pulley.
Note: Clean the capscrew threads and holes in the
sheaves thoroughly to avoid capscrew breakage during
reassembly.
b. The outer half of the pulley is screwed onto the
hub extension of the inner half. Some pulleys
are provided with flats, and some with lugs for
barring.
c. Bar the engine over to roll the belt outward on
the pulley as the outer half is turned in.
d. Adjust the belt(s) to the tension indicated in
Table 2-1.
e. Turn the outer sheave(s) in enough to align the
capscrew holes.
f. Start the capscrews and tighten alternately and
evenly. Final tension is: 5/16-18 capscrew, 10
to 12 ft-lbs [14 to 16 N•m] 3/8-16 capscrew, 17
to 19 ft-lbs [23 to 26 N om] g. Bar the engine
over one or two revolutions to seat the belt.
h. Recheck the belt tension.
Inline Engine Water Pump Belts (With Idler)
1. Loosen the capscrews and lockwashers or locknut
securing the idler pulley to the bracket or water
pump. Fig. 2-4.
2. Using a pry bar (NTA) or adjusting screw (FFC)
adjust the idler pulley until the proper belt tension is
indicated on the gauge. See Table 2-1.
3. Secure the idler pulley or bracket in position by
tightening the locknut or capscrews and lockwashers
to 45 to 55 ft-lbs [61 to 75 N m] torque.
Note: The self tensioning idler on V-1710 belt driven
water pumps requires no adjustment or belt tension
check.
Fan Drive Belts
1. Loosen the large locking nut on the fan hub shaft or
the capscrews securing the fan hub shaft to the
mounting bracket. The fan hub will fall out of line
when this is done.
2. Turn the adjusting screw to increase the belt
tension.
3. Tighten the locknut or capscrews until the fan hub is
straight. Snug the nut to maintain the hub in proper
alignment with the fan hub bracket.
Caution: Do not adjust to full tension with the
adjusting screw, as this would result in
overtightening.
4. Belt tension should read as indicated in Table 2-1 on
applicable gauge.
5. Tighten NH/NT Engines locknut to 400 to 450 ft-lbs
[542 to 610 N m]; then back off 1/2 turn. Tighten
the four 1/2 inch capscrews, Fig. 2-5, on NTC-350
FFC Engines to 75 to 85 ft-lbs [101 to 115 N.m].
On V-903 Engines tighten capscrews to 75 ft-lbs [102
Fig. 2-4, (N11974). Water pump with idler
N.m] or single nut to 450 ft-lbs [610 N.m].
6. Recheck the belt tension.
7. Back out the adjusting screw one-half turn to
Note: The self tensioning backside idler on KT/KTA2300
and KTA-3067 belt driven fan requires no belt tension
check.
Generator/Alternator Belts
Belt tension should be as indicated in Table 2-1 when
measured with the applicable gauge.
2-9
prevent breakage.
Fig. 2-5, (OM10161). Fan hub installation, NT-350 FFC
MASHINESOFT.COM
09120146259
Operation and Maintenance
Construction and Industrial
5. Do not allow belts to rub any adjacent parts 6.
Adjust belts to the proper tension.
Readjusting New Belts.
All new belts will loosen after running for 5 minutes and
must be readjusted to "belt tension after run-in" Ref.
Table 2-1.
Check Oil Bath Cleaner Oil Level.
Daily check oil level, Fig. 2-6, in the oil bath air cleaner
to be sure the oil level in the cup is at the indicated
mark. Refill as required.
*Cummins Engine Company, Inc. recommends the use
of dry type air cleaners.
Belt Installation.
If the belts show wear or fraying, replace as follows:
1. Always shorten the distance between the pulley
centers so the belt can be installed without force.
Never roll a belt over the pulley and never pry it on with
a tool such as a screwdriver. Either of these methods
will damage the belts and cause early failure.
2. Always replace the belts in complete sets. Belts
riding depth should not vary over 1/16 in [1.6 mm]
on matched belt sets.
3. Pulley misalignment must not exceed 1/16 in 11.
4. Belts should not bottom on the pulley grooves nor
6 mm] for each ft 10.3 m] of distance between
the pulley centers.
should they protrude over 3/32 in [2.4 mm] above
the top edge of the groove.
Check for Damage.
Visually check the fuel system, etc., for misadjustment
or tampering; check all connections for leaks or
damage. Check the engine for damage; correct as
necessary.
Fig. 2-6, (Nl1001). Checking oil level in air cleaner
2-10
Maintenance Instructions
MASHINESOFT.COM
09120146259
"A" Maintenance Checks-Weekly
Repeat Daily Checks
Check Air Cleaner
Clean Pre-Cleaner and Dust Pan
Under extremely dirty conditions an air pre-cleaner may
be used. Clean the pre-cleaner jar and dry-type air
cleaner dust pans daily or more often, as necessary,
depending on operating conditions.
Check Inlet Air Restriction
Mechanical Indicator
A mechanical restriction indicator is available to indicate
excessive air restriction through a dry-type air cleaner.
This instrument can be mounted in the air cleaner outlet
or on the vehicle instrument panel. The red flag (1, Fig.
2-7) in the window gradually rises as the cartridge loads
with dirt. After changing or replacing the cartridge, reset
the indicator by pushing the reset button (2).
Fig. 2-8, (N21905). Vacuum switch to check air inlet
1. Air restriction on turbocharged engines must not
exceed 25 inches [635 mm] of water or 1.8 inches [46
mm] of mercury under full power conditions.
2. Naturally aspirated engine air restriction must not
exceed 20 inches [508 mm] of water or 1.5 inches [38
mm] of mercury at air intake manifold at rated speed.
Clean or Replace Air Cleaner Elements
The paper element in a dry-type air cleaner, Fig's. 2-9,
2-10, 2-11 and 2-12, may be cleaned several times by
Fig 2-7, (CGS-20). Air inlet restriction indicator
Note: Never remove the felt washer from the indicator.
It is necessary to absorb moisture.
Vacuum Indicator
Vacuum switches, Fig. 2-8, are available which actuate
a warning light on the instrument panel when the air
restriction becomes excessive.
using air to blow off dirt or by washing with nonsudsing
household detergent and water at 120 to 1400F [49 to
600C], then drying with compressed air, approximately
30 psi [306 kPa]. Do not hold the air jet too close to the
paper element.
Elements that have been cleaned several times will
finally clog and air flow to the engine will be restricted.
After cleaning, check the restriction as previously
described and replace the element if necessary.
Caution: Holes, loose end seals, dented sealing
surfaces and other forms of damage render the
cleaner inoperative and require immediate element
replacement.
To change the element:
1. Loosen the wing nut (1, Fig. 2-9) securing the
2-11
30
Loading...