richmelcole@sbcglobal.net Posted January 10, 2022 Share Posted January 10, 2022 My 7.5 Onan Generator fuel lines to the filter are difficult to disconnect. The inlet to the filter is a rigid tubing from the fuel pump with flare connectors. The filter outlet is a flexible hose to the motor. Both filter flare connectors are rounded from using a wrong type of wrench on them. Has anyone replaced the rigid tubing with a flexible hose which would make changing out the filter much easier or am I stuck with replacing the OEM parts? Rich Link to comment Share on other sites More sharing options...
Paul J A Posted January 10, 2022 Share Posted January 10, 2022 Get rid of that filter, and mount a filter, as used for AQ fuel filter, on the outside of the rear wall of the Genny Enclosure. Simple and so convenient. NAPA can make up the necessary fuel lines. 1 Link to comment Share on other sites More sharing options...
Chuck B 2004 Windsor Posted January 10, 2022 Share Posted January 10, 2022 Onan used the rigid tubing for a reason. Replace the connectors with the OEM parts, and the filter. Then add a external filter that is mounted to the drivers side, side of the genset. 1 Link to comment Share on other sites More sharing options...
Rick A Posted January 10, 2022 Share Posted January 10, 2022 37 minutes ago, Paul A. said: Get rid of that filter, and mount a filter, as used for AQ fuel filter, on the outside of the rear wall of the Genny Enclosure. Simple and so convenient. NAPA can make up the necessary fuel lines. I’d be interested to get the full details on that mod. Any chance of photos, part #, etc? Link to comment Share on other sites More sharing options...
DavidL Posted January 10, 2022 Share Posted January 10, 2022 I would get some vice grips and remove the old filter. Then, if the hard line allows, slide the stripped fitting backwards and cut of the flare with a hack saw or ideally tubing cutter. Note the tubing cutter will cut off more of the line than the hack saw...but the hack saw 1) could small chance spark 2) could leave filings in the line. Then, get a new flared fitting, slide that on the old hard line, and use a flaring tool to rebuild the flare. This all assume you have enough hard line slack to connect everything back together... Otherwise, get fuel injection hose and put double fuel injection clamps on it to get to a quality replacement filter. Or, use the new fuel line and eliminate the filter and put a remote filter on like Chuck shows. That's likely what I would do. Looks like Chuck has a water separator in the filter assy which is nice. Just note you are working with gasoline that is very flammable. Have to put that disclaimer in because we don't know who is doing this work... Link to comment Share on other sites More sharing options...
scottjo02 Posted January 11, 2022 Share Posted January 11, 2022 The suggestions by others for an external filter is a good idea but I chose to replace the rigid OEM filter line with a flex line leaving the OEM filter in place. It makes the connections much easier to make up. I also always use flare nut wrenches which work much better than open ends. Scott 1 Link to comment Share on other sites More sharing options...
Chuck B 2004 Windsor Posted January 11, 2022 Share Posted January 11, 2022 Replace the Onan fuel filter bringing the filter up to Onan's specs. Then install the Racor external filter that has a cartridge matching the Onan's filter specs. With the Racor specs being the same as the Onan's specs you will not have to replace the Onan filter again. Just replace the Racor filter. Doing that you will not have to lay on the ground, removing the cross member, and getting a arm pit full of diesel fuel. Link to comment Share on other sites More sharing options...
Chuck B 2004 Windsor Posted January 11, 2022 Share Posted January 11, 2022 23 hours ago, DavidL said: I would get some vice grips and remove the old filter. Then, if the hard line allows, slide the stripped fitting backwards and cut of the flare with a hack saw or ideally tubing cutter. Note the tubing cutter will cut off more of the line than the hack saw...but the hack saw 1) could small chance spark 2) could leave filings in the line. Then, get a new flared fitting, slide that on the old hard line, and use a flaring tool to rebuild the flare. This all assume you have enough hard line slack to connect everything back together... Otherwise, get fuel injection hose and put double fuel injection clamps on it to get to a quality replacement filter. Or, use the new fuel line and eliminate the filter and put a remote filter on like Chuck shows. That's likely what I would do. Looks like Chuck has a water separator in the filter assy which is nice. Just note you are working with gasoline that is very flammable. Have to put that disclaimer in because we don't know who is doing this work... Where did gasoline generators enter the discussion? The 7.5 Onan generator is a diesel generator. Link to comment Share on other sites More sharing options...
Steve P Posted January 11, 2022 Share Posted January 11, 2022 54 minutes ago, Chuck B 2004 Windsor said: Replace the Onan fuel filter bringing the filter up to Onan's specs. Then install the Racor external filter that has a cartridge matching the Onan's filter specs. With the Racor specs being the same as the Onan's specs you will not have to replace the Onan filter again. Just replace the Racor filter. Doing that you will not have to lay on the ground, removing the cross member, and getting a arm pit full of diesel fuel. A deodorant with an unmistakable fragrance that lasts for days - one of the many joys of owner maintenance! Link to comment Share on other sites More sharing options...
Chuck B 2004 Windsor Posted January 11, 2022 Share Posted January 11, 2022 Where did a gasoline generator enter the discussion? The Onan 7.5 generator is a diesel generator. Link to comment Share on other sites More sharing options...
richmelcole@sbcglobal.net Posted May 8, 2022 Author Share Posted May 8, 2022 Just replaced the old filter with a spin-on filter head on the outside of the sound enclosure. What micron rating should the filter be? Rich Link to comment Share on other sites More sharing options...
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