BAC Forum

General Boards => Technical Support => Topic started by: Bill Heffernan on October 16, 2025, 12:45:10 AM

Title: Onan Fuel Pump Replacement
Post by: Bill Heffernan on October 16, 2025, 12:45:10 AM

I am trying to replace the fuel pump on our generator. I can see the small access door, but I cannot get anywhere close to it. Should my generator slide be coming out further? What am I missing? Thanks!

Title: Re: Onan Fuel Pump Replacement
Post by: Zeb Severson on October 16, 2025, 05:32:04 AM

Someone with your model might have a different experience, but I have a HDCAA and there is no way to replace it through that hole and access panel. If you have an HDKA or HDKB you might have better luck. I'm curious, do you know it needs to be replaced? You can measure the volume of fuel that it pumps to confirm if it is sufficient or needs to be replaced.

Title: Re: Onan Fuel Pump Replacement
Post by: Bill Heffernan on October 16, 2025, 09:24:32 PM

Thanks Zach. Ours is a HDKCA. What we are experiencing frequent shutdowns with a code 36. The filter is good and fuel levels are good. The options appear to be the fuel pump or control board. A fuel pump is a far less expensive option, so I thought I would start there. I didn't realize the challenge of getting to it.

Title: Re: Onan Fuel Pump Replacement
Post by: Steve Huber on October 16, 2025, 10:45:56 PM

Bill
Suggest you replace the fuel filter even if current one is "new". It can cause the symptom you are describing and IMHO a lot cheaper and easier than going after the pump. Also make sure you have at least 1/2 a tank of fuel and the lines from the tank to the geni are in good shape. Code 36 indicates shutdown signal is coming from something other than the control board so I don't think that is your culprit.
Steve

Title: Re: Onan Fuel Pump Replacement
Post by: Eric Maclean Co-Admin on October 17, 2025, 04:24:41 AM

Bill
Before you get into trying to get the pump out I would suggest you remove the fuel return line at the back of the Gen set and run a short piece of hose into a catch bottle to check your fuel return fuel flow this could help determine if the pump is keeping up.

Also on these coaches of this age it's not uncommon for the fuel line between the tank and the Gen set to get dry rotted and allow the pump to suck air causing fuel starvation issues you might want to remove the fuel feed and return lines off the back of the Gen set and run a good pair of lines into a can of diesel fuel to see if the unit will work properly.

Eric

Title: Re: Onan Fuel Pump Replacement
Post by: Bill Heffernan on October 18, 2025, 05:09:55 PM

Thanks, I'll be down there winterizing today. I'll run a test on the fuel lines. I don't think the fuel filter is the culprit, that was the first item I swapped out and there was no change in the generator dying. That's as always for the assistance.