Oshkosh JLG 400S, Service And Maintenance Manual

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SECTION 3 - CHASSIS & TURNTABLE
3-122 – JLG Lift – 3120895
Diagnostic Aids
This procedure is intended to diagnose a vehicle operat-
ing on LPG. If the vehicle will not continue to run on LPG,
refer to Hard Start for preliminary checks. Before proceed-
ing with this procedure, verify that the vehicle has a suffi-
cient quantity of fuel and that liquid fuel is being delivered
to the LPR. Also, ensure that the manual shut off valve on
the LPG tank is fully opened and that the excess flow valve
has not been activated.
Tools Required:
• 7/16 Open end wrench (for test port plugs)
• DVOM (GM J 39200, Fluke 88 or equivalent).
• 12 volt test light
Diagnostic Scan Tool
• Diagnostic Display tool.
Pressure Gauges
• IMPCO ITK-2 Test kit
• Water Column Gauge / Manometer (GM 7333-6 or
equivalent).
• 0-10 PSI Gauge
Test Description
The numbers below refer to step numbers on the diagnos-
tic table.
5. This step determines if the LPR requires replacement
6. This step determines if the problems are in the mechan-
ical side of the Pressure Regulator or the Electronic Voice
Coil
10. This step determines if the Mixer requires replacement
14. This step determines if the Lock Off requires replace-
ment
17. This step determines if the Fuel Filter requires replace-
ment.