Servicing Fuel Pump; Servicing Glow Plugs; Servicing And Adjusting V-Belts; Water Pump V-Belt - Carrier DM-4 Power Pack Operation And Service Manual

4.3.7 Servicing Fuel Pump

Due to foreign particles in the fuel, the fuel filter may
become plugged or restricted, and the engine will lose ca-
pacity. The filter must be cleaned on a regular schedule
such as unit pre-trip or when the oil and fuel filters are
changed.
1. Turn the nut counter-clockwise to loosen and re-
move (item 1, Figure 4-3)
2. Remove banjo fitting (item 2) and let it hang loose,
making sure to keep copper rings (item4) for replacement.
3. Turn filter (item 3) counter-clockwise and remove.
Check and clean.
4. To install reverse steps 1 through 3.
2
1. Nut
2. Banjo
3. Filter
4. Copper Rings
Figure 4-4. Mechanical Fuel Pump

4.3.8 Servicing Glow Plugs

When energized, the glow plugs draw a nominal 7.0
amps at 10.5 volts. When servicing, the glow plug is fitted
carefully in the cylinder head to prevent damage to glow
plug. Torque value for the glow plug is 14 to 18 ft-lbs (1.9 to
2.5 mkg).
a. Checking for defective glow plug
1. One method is to place an ammeter (clip on type
ammeter) in series with each glow plug and energize the
glow plugs. Each plug (if good) should show 7 to 10 amps
draw.
3
1
4
1
2. A second method is to disconnect the wire connec-
tion to each plug and test the resistance from the plug to
ground on the engine block. Threading should be 0.7 to 1.2
ohms if the plug is good.

4.4 SERVICING AND ADJUSTING V-BELTS

Beware of V-belts and belt driven components
as the unit can be started remotely

4.4.1 Water Pump V-Belt

The water pump V-belt is driven by a sheave on the en-
gine crankshaft. Frayed, cracked or worn belts must be re-
placed. Adjustment is achieved by altering the position of
the front side idler.
When replacing the V-belt avoid excessive force when
applying tension to the V-belt to prevent damage to the
water pump bearings. Refer to NO TAG for correct belt
tension.

4.4.2 Alternator V-Belts

a. To Replace V-Belts
1. Disconnect negative battery cable and loosen V-belt
tension
2. Match mark adapter to engine flywheel (see figure
4-4-A) for ease of assembly.
3. Remove six bolts (5/16-18 x 1) securing adapter
drive sheave to engine flywheel, Figure 4-4-A.
4. Insert 2 of the six bolts (5/16-18 x 1) into the
threaded holes (jacking holes) provided on engine adapt-
er. Jack adapter from engine flywheel. Remove the 2 bolts
from adapter. Insert a pry bar between engine flywheel
and adapter, Figure 4-4-A and slide the adapter-sheave to-
ward the compressor enough to change the V-belts as
shown in Figure 4-4-B. Replace V-belts.
5. Pry the adapter back toward the flywheel or use
5/16-18 x 2-1/2 bolts (3) in every other hole of the adapter
and take up evenly on the bolts until the 5/16-18 x 1 bolts
will start in the engine flywheel. Apply thread sealer (Loc-
tite #262) to the bolts used to secure the adapter to the fly-
wheel. Take up on all bolts evenly and then torque to a val-
ue of 28 ft-lb (3.87mkg).
6. Place V-belts on the alternator sheave and adjust
tension. Refer to Table 4-1 for correct belt tension. Using
excessive tension may damage alternator bearings.
7. Reconnect battery ground cable and start unit. Al-
low to run for 10 minutes to allow belts to seat.
4-4
WARNING