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Topic: Fuel Filter Maintenance for 8.3 Cummins Mechanical (Read 10038 times) previous topic - next topic

Re: Fuel Filter Maintenance for 8.3 Cummins Mechanical

Reply #25 –
Without the electric pump "on" the primary filter is under vacuum instead of pressure. While at idle my primary filter is under about 4" Vacuum. About 6" while running at 1800 rpm.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Fuel Filter Maintenance for 8.3 Cummins Mechanical

Reply #26 –
Draining clear fuel from the filter only tells you there is no water accumulated in the filter,the filter could have alot of dirt etc.
Cummins lists 6K miles for the filter change interval,I reccomend to change filters before the trip.The primary filter is before the
engine mounted pump so the vacuum is normal.My point on the previous post was that without seeing and looking at your
fuel delivery system you may just be putting more fuel thru the system and back in the tank.
96 U270 BUILD 4810
85 380SL
Drummonds TN.
 

Re: Fuel Filter Maintenance for 8.3 Cummins Mechanical

Reply #27 –
Quote from: Tim –

- Electric boost pump, shown in a prior post, measured 11.9 volts and drew 2.3 amps


If this reading was with the chassis battery above 13 VDC (either engine running and/or shore power charger on chassis battery) this is proof that you need to re-wire it.  Running a pump designed to be run in a moving vehicle (read that with the alternator charging, so 13+ VDC) will be very unhappy with sub-12 VDC power.

Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
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Chairman FMCA Technical Advisory Committee 2011-2020