Yanmar 3TNV82A-B Service Manual page 238

ENGINE
Cleaning the EGR valves
A
WARNING
FUME / BURN HAZARD!
• Always read and follow safety related
precautions found on containers of
hazardous substances like parts
cleaners, primers, sealants and
sealant removers.
• Failure to comply could result in death
or serious injury.
A
CAUTION
FLYING OBJECT HAZARD!
• ALWAYS wear eye protection when
servicing the engine and when using
compressed air or high-pressure
water. Dust, flying debris, compressed
air, pressurized water or steam may
injure your eyes.
• Failure to comply may result in minor
or moderate injury.
The EGR valves must be periodically cleaned every
1500 hours because, as exhaust gas circulates
through them for a prolonged time, carbon is
deposited on their inner surfaces, possibly
deteriorating the EGR ratio.
6-106
To remove deposited carbon, use compressed air
(0.19MPa(2kg/cm2) or lower). If the valves are
heavily fouled, use carbon cleaner, kerosene, or
some other liquid capable of removing carbon as
well as a soft brush to clean the valves, taking care
not to damage their parts.
When cleaning the valves, take extreme care to
prevent water, solvent, cleaner, and other liquid
from entering into the motor and coupler terminals;
otherwise, failure may result.
NEVER use high-pressure water or
compressed air at greater than 28 psi
(193 kPa; 19 686 mmAq) or a wire brush
to clean the radiator fins. Radiator fins
damage easily.
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Lead valves
Similarly to the EVR valves, the lead valves must
be periodically cleaned every 1500 hours because,
as exhaust gas circulates through them for a
prolonged time, carbon is deposited on their inner
surfaces, possibly deteriorating the EGR ratio.
To remove carbon deposited inside the lead valves,
disassemble and clean them.
(1)
(2)
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1 – Case
2 – Stopper
3 – Valve
4 – Machine screw
CAUTION
(3)
(4)
Figure 6-158
TNV DI Service Manual
EGR system
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