Service manual

G420F(FE) Service Manual Chapter 6. LPG FUEL DELIVERY SYSTEM 211
3. Apply compressed air, wait for air to exit the hose
barb in the test port, and then connect the
Magnehelic gauge (Figure 36) to the hose barb
using the vacuum hose or vinyl tubing. This
prevents the gauge from reading maximum
pressure due to the large velocity of compressed
air entering the primary chamber.
4. Make sure there is no leakage at any of the
fittings. The static pressure should read between
40-60” of water column on the Magnehelic gauge
and maintain a constant pressure for 60 seconds.
Figure 36. Magnehelic Gauge Connection to Hose
Barb
5. If the pressure reading begins to increase, a leak
is most likely present at the primary valve, either
the primary valve o-ring or the valve itself. If a leak
is present the regulator should be replaced.
6. If the pressure begins to decrease, the secondary
seat is probably not making an adequate seal and
is leaking. The regulator should be replaced.
7. If the test is successful, re-install the primary test
port plug and check the fittings for leaks. See
Chapter 5 for installation of the N-2007 regulator.
NOTE : The N-2007 primary stage pressure can
also be tested at idle on a running engine. The N-
2007 primary pressure should be between 40 inH20
(99.635 mbar) and 55 inH20 (136.999 mbar) at 750
rpm, idle.
CAUTION
•LP gas is highly flammable. To prevent
personal injury, keep fire and flammable
materials away from the lift truck when work is
done on the fuel system.
•Gas vapor may reduce oxygen available for
breathing, cause headache, nausea, dizziness
and unconsciousness and lead to injury or
death. Always operate the forklift in a well
ventilated area
Liquid propane may cause freezing of tissue or
frostbite. Avoid direct contact with skin or
tissue; always wear appropriate safety
protection including gloves and safety glasses
when working with liquid propane.