Onan Fuel Filter?

Funtime-FRF

Senior Member
Joined
Oct 28, 2005
Posts
323
While changing the oil today on the Onan 7.5 Quiet Diesel Gen. I was looking at the fuel filter(S). I plan to replace the one filter that looks like a square box with two fittings tomorrow but I noticed what looked like another filter very close to it that has two wires coming from it. What is this filter and what are the wires for? Thanks for your help.
By the way, any tips for how to change the square filter without getting fuel oil all over myself would be greatly appreciated.
 
While changing the oil today on the Onan 7.5 Quiet Diesel Gen. I was looking at the fuel filter(S). I plan to replace the one filter that looks like a square box with two fittings tomorrow but I noticed what looked like another filter very close to it that has two wires coming from it. What is this filter and what are the wires for? Thanks for your help.
By the way, any tips for how to change the square filter without getting fuel oil all over myself would be greatly appreciated.
 
There is a fuel filter, air filter and oil filter. Unless you are somewhat of a magician, be prepared to have some diesel fuel in your armpit when you change that fuel filter
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Also don't be discouraged if the new fuel filter leakes when you replace it. Bill at Cummins South told me that if you don't have a leak, you are "REALLY GOOD." His Onan man has about a 50% success rate on his work and he does it all the time. Just take your time and cross both eyes, fingers, and toes. It really is not that hard just a little frustrating when it leakes. I have changed two and batted 50%.
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by fun time:
While changing the oil today on the Onan 7.5 Quiet Diesel Gen. I was looking at the fuel filter(S). I plan to replace the one filter that looks like a square box with two fittings tomorrow but I noticed what looked like another filter very close to it that has two wires coming from it. What is this filter and what are the wires for? Thanks for your help.
By the way, any tips for how to change the square filter without getting fuel oil all over myself would be greatly appreciated. </div></BLOCKQUOTE>

The one without the wires is the filter while I believe that the one with the wires is the fuel pump.
 
Wear gloves and an old shirt. That filter is fun to chnage, just did mine. Picked up my new one at Napa, the had it in stock. No leaks, so I must be GOOD. Don't forget to hold your switch in the off postion for a minute to reprime the system!!
 
That thingy you see that looks like a filter with 2 wires is your electric fuel pump.

Words of advice on changing your fuel filter. Use a fitting wrench on the fittings. They are brass and easy to strip. Be careful to not cross thread the fittings when installing the new filter. Be sure the fittings are tight when done. Check for leaks.
You are going to get diesel fuel on you when you do this. When done wash first with cold water, then warm water and soap.

You haven't used a biocide in your fuel have you? That stuff contains 2,4D, one of the ingredients of Agent Orange of Vietnam era which will be absorbed through your skin.
 
Just changed mine a couple weeks ago. I plugged the inlet hose with a golf tee as soon as it was disconnected. This minimized the fuel leak until I could get the new one in place and attached. Hand tighten as much as possible before using wrenches. Be sure to use a wrench on the filter fitting AND on the fuel line fittings to prevent damage to the filter. Guess I was lucky, no leaks.
 
Hi Denny: Can't help you with the filter change. However, if you get diesel fuel on you, tomato juice, fresh or canned, or a sliced lemon, will get rid of the smell. Then soap and water. If it gets on the clothes, (if you are like me), I wear the worst gundgies I can find and throw them away after maintenance. "Mean Green", will take any spilled fuel off your equipment post haste. It is water flushable and safe. Happy RV'g
 
I bought a brass cap at the local hardware store to cap the inlet line and stop the diesel from leaking that way I could take my time with the install--no leaks.
 
Well, you guys were all right in your pointers especially the one about getting diesel fuel down your arm pits. Yuk! All went well but those brass fittings were so tight I rounded one point on the in-line nut but was able to get it off and re-tighten for the new fuel filter. What is interesting that nut is a 7/16 and the first wrench I grabed was a little sloppy fitting while the second wrench (same size) fit perfect.
Must have been the difference between a China wrench and a Craftsmen. Thanks for all you help everyone. Much appreciated.
 

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