Racor 500 fuel level

Don S/V ILLusion · Jul 6, 2014

Re: Raco 500 fuel level

Did you move the filter and is it below the level of the tank bottom?

WayneH · Jul 7, 2014

Re: Raco 500 fuel level

I think you have too much alcohol in your fuel and your clams are loose again.

I'm sorry. I just couldn't resist.

It does sound like you have air coming into the fuel line. And tightening the clamps should have solved your condition. The other leak point is the tank connection.

But is sounds as though your system is robust enough that you are rejecting the air bubbles at a different location. I realize that each engine manufacturer does it differently but my engine has an air bleed/fuel return on top of the secondary filter. When I replace the Racor filter, I just turn the engine to ON and let the fuel pump (electric) run until I hear a steady stream of fuel returning to the tank.

I hope this helps you.

Maine Sail · Jul 7, 2014

Sounds like a gravity issue. Fluids are self leveling and some may be flowing back to the tank.

woodster · Jul 7, 2014

Maine Sail said:
Sounds like a gravity issue. Fluids are self leveling and some may be flowing back to the tank.

if the filter is higher that the fuel tank why not run a fuel line that has a high loop above the filter in it between the tank and the filter or would that trap air in the line...

Bill1565 · Jul 7, 2014

Maine Sail said:
Sounds like a gravity issue. Fluids are self leveling and some may be flowing back to the tank.

My Racor 500 is above the top of my tank. Never is full to the brim, but never down more than 1/4" or so. I concur, some flows down hill, but if connections are tight, then vacuum limits back flow.

WayneH · Jul 9, 2014

NYSail said:
Hello all! Recently changed fuel filters and have noticed when I keep rechecking primary filter the fuel in the bowl is not at the top. I have topped it off 3 times so far over a matter of 3 weeks. Never noticed this before as have never checked fuel levels this often..... At first I thought it was just filters absorbing fuel. Do not ever have problem with air in engine and also replaced fuel pump in 2012. I tightened all clams in hose leading from tank today.......

Any advise or opinions?

I knew it was a typo but I just couldn't resist. But I've also enjoyed reading this thread as I have learned something about my system while perusing the thread.

RichH · Jul 10, 2014

Re: Raco 500 fuel level

The first prime suspect for this would be a pinched gasket or O-ring on the Racor when you reinstalled.
This is especially the probability if you re-used the fuel-swollen (now much 'softer') gaskets/Orings.
If you used new gaskets/o-rings they must be 'lubricated' with clean fuel - to prevent such 'pinching' deformation when reinstalling (and over-tightening).

If you "un-tightened" any of the filter's or fuel system 'connectors', you could have inadvertently cracked one.

All the above conditions can easily lead to your system 'sucking air' ... but in this case just enough to displace a small amount of fuel and become a 'trapped bubble' in the 'topside' of your filter(s).

Ron20324 · Jul 15, 2014

Re: Raco 500 fuel level

Is this situation actually causing some problem, or is it just the fact that the level is lower? I'd have to think by the time the engine starts and runs a few seconds that the full fuel level is back up to snuff.

Ron20324 · Aug 9, 2016

[QUOTE="...level in filter now stays at top..... Gravity issue.[/QUOTE]

Sir Isaac Newton would be happy to hear that!

woodster · Aug 9, 2016

NYSail said:
He was a swell guy

you don't have to hit me on the head with an apple.......