Had a similar problem to yours several years ago. After doing most of what you have done, my diesel mechanic suggested just replacing the Racor MA 500(?) top plate since even a little over tightening can push the middle down enough that the O-ring on the circumference will leak enough that after running for a while the air inside it gets into the fuel lines. This was a cheap enough thing to do that I did it—along with a few other ‘fixes’ and the problem went away. Since it was not the only change I made, I can’t be certain that the new top plate solved the problem or if it was something else. Note I am pretty sure that the instructions for the Racor say to only hand tighten this plate or something similar—I now know why! Given how little extra tightening it would take at the Center to deflect the circumference/O-ring joint enough to suck air in, (probably a few microns could break the vacuum seal) and over time you have air bubbles that get to the engine or at least prevent fuel from getting to the engine. FWIW, Charlie Nelson
Sent from the all new AOL app for iOS On Thursday, September 23, 2021, 12:36 PM, David Knecht via CnC-List <cnc-list@cnc-list.com> wrote: I meant bypass the Racor, turn on the pump and collect fuel into a secondary container to test. I agree that I would not run the engine that way. I am presuming that the flow of fuel through the filter should be a good test of the system since the problem was I was getting air into the primary Racor holder, so a vacuum leak likely somewhere. Dave S/V Aries1990 C&C 34+New London, CT On Sep 23, 2021, at 9:53 AM, Neil Andersen <neil.eric.ander...@gmail.com> wrote: I would think that risky. If the Racor is the issue because it is doing its job and there is particulate matter coming from the tank, bypassing it will allow the matter to get to the engine. Neil Andersen1982 C&C 32, FoxFireRock Hall, MD 21661484-354-8800From: David Knecht via CnC-List <cnc-list@cnc-list.com> Sent: Thursday, September 23, 2021 9:36:44 AM To: CnC CnC discussion list <cnc-list@cnc-list.com> Cc: David Knecht <davidakne...@gmail.com> Subject: Stus-List Re: Fuel pump Hi Dennis- The Racor looks OK, but of course that says nothing. I don’t know the Racor model but it is older since it does not have the threaded top that you can add a gauge to. Since that is a more expensive alteration, I thought I would replace the fuel lines first and see if that fixes the problem. If not, I thought I would bypass the Racor and see if it works that way and if so, replace the Racor itself. Dave S/V Aries1990 C&C 34+New London, CT <pastedGraphic.tiff> On Sep 23, 2021, at 9:31 AM, Dennis C. via CnC-List <cnc-list@cnc-list.com> wrote: What type of fuel filter do you have? If it's a Racor MA500, the top may be warped or the gasket may be cracked or displaced. Those are not infrequent issues with that filter. Either condition could result in air inleakage. -- Dennis C.Touche' 35-1 #83Mandeville, LAThanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
