Doosan D20G, Service Manual

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4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 48
2. If necessary, adjust the V-belt tension. Loosen
the adjusting bolt (Figure 5-5, (1)) and move the
alternator (Figure 5-5, (2)) with a pry bar (Figure
5-5, (3)) to tighten the V-belt to the desired
tension. Then tighten the adjusting bolt.
Figure 5-5
3. Tighten the V-belt to the proper tension. There
must be clearance (Figure 5-6, (1)) between the
V-belt and the bottom of the pulley groove. If
there is no clearance
(Figure 5-6, (2)) between
the V-belt and the bottom of the pulley groove,
replace the V-belt.
Figure 5-6
4. Check the V-belt for cracks, oil or wear. If any of
these conditions exist, replace the V-belt.
5. Install the new V-belt. Refer to the table for
proper tension.
New V-Belt Tension
A B C
5/16 - 7/16 in.
(8 - 12 mm)
3/16 - 5/16 in.
(5 - 8 mm)
1/4 - 7/16 in.
(7 - 11 mm)
6. After adjusting, run the engine for 5 minutes or
more. Check the tension again using the
specifications for a used V-belt.
Used V-Belt Tension
A B C
3/8 - 1/2 in.
(10 - 14 mm)
1/4 - 3/8 in.
(7 - 10 mm)
5/16 - 1/2 in.
(9 - 13 mm)
Every 50 Hours of Operation
After you complete the initial 50 hour maintenance
procedures, perform the following procedures every
50 hours thereafter.
• Drain Fuel Filter / Water Separator
• Check Battery
Drain Fuel Filter / Water Separator
4TNV98 & 4TNE98 (For China) Engine
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
When you remove any fuel system component
to perform maintenance (such as changing the
fuel filter) place an approved container under
the opening to catch the fuel.
NEVER use a shop rag to catch the fuel. Vapors
from the rag are flammable and explosive.
Wipe up any spills immediately.
Wear eye protection. The fuel system is under
pressure and fuel could spray out when you
remove any fuel system component.
Failure to comply will result in death or serious
injury.