Daily Maintenance of Cummins NT Diesel Engines
As mentioned on the before
article, Cummins NT diesel engine maintenance is divided
into four level maintenance. Different level maintenance, the check items are
also different. In this article, we mainly talk about the "A"
maintenance checks - daily. If you are interested or want to know about the
related operation, continue reading.
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
necessary.
Comparison and intelligent
interpretation of the daily report along with a practical follow-up action will
eliminate most failures and emergency repairs.
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 Oil Level
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. For accurate readings, the oil level
should not be checked for approximately 15 minutes after the engine is
shutdown. 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.
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 folow:
Using the appropriate gauge,
Fig 2-1; check and or adjust belts to the tension as indicated in Table 2-1.
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.
Inline Engine Water Pump
Belts (With idler)
1. Loosen the capscrews and
lockwasher or locknut securing the idler pulley to the bracket or water pump.
Fig.2-2.
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
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 lock-nut or
caps-crews 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
the indicated in Table 2-1 on applicable gauge.
5. Tighten NT Engines locknut
to 400 to 450 ft – lbs ]542 to 610 N*m]; then back off 1/2 turn. Fig,2-3.
6. Recheck the belt tension.
7. Back out the adjusting screw
one-half turn to prevent breakage.
Generator/Alternator Belts
Belt tension should be as
indicated in Table 2-1 when measured with the applicable gauge.
Belt Installation
If the tension 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[1.6 mm] for each ft [0.3m] of distance between the pulley
centers.
4. Belts should not bottom on
the pulley grooves nor should they protrude over 3/32 in [24 mm] above the top
edge of the groove, or 1/32 in [0.8] below the top edge of the groove.
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 1 hour and must be retensioned if necessary. Ref. Table 2-2.
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.
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