HomeRepair guidesLeakage Test:

Cummins/Onan — Leakage Test:

For these Cummins/Onan models: 12, 0MDJC-3CR, 12.0MDJF-53CR, 15.0MDJF-3cR, 3omDJaiR, 4.0MCCK-3cR, 6.0MDJE-53CR, 6.5MCCK-3CR, 6.OMDJE-S18R, 612-4792, 7.SMOJE-18R, ISOMDJF-3GR.

Applies to: Cummins Onan 12 0Mdjf 53Cr, Cummins Onan 15 0Mdjf 3Cr, Cummins Onan 3Omdjair, Cummins Onan 4 0Mcck 3Cr, Cummins Onan 6 0Mdje 53Cr, Cummins Onan 6 5Mcck 3Cr, Cummins Onan 6 Omdje S18R, Cummins Onan 7 Smoje 18R, Cummins Onan Isomdjf 3Gr, Cummins Onan Mcck Spec H, Cummins Onan Mdje 8, Cummins Onan Spec H, Cummins Onan Tsmdje 3Cr

Procedure

  1. 1. Slowly depress hand lever until nozzle test gauge indicates 285 PSI (1966 kPa) below specified opening pressure.
  2. 2. Consider nozzle leak-proof if no fuel (not even

Source: manual:932-0405 Onan Marine Genset MCCK MDJA MDJC MDJE MDJF Training Manual (07-1979).pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.