Beware the check ball valve on your Racor!

[bwindrope]

Originally Posted by a64pilot

OK, he has a check valve because his filter has a plunger pump, vast majority of Racor’s are 500 series and I have never seen a pump.

This is correct. The 500 has a ball valve, but it must serve a different function than on the 200 series. Maine Sail has a great post on this site about how to make sure you have the O-ring turned correctly for the stainless ball valve on the 500. The ball on the 200 series is some kind of rubber and serves to allow the pump to do it's job.

[a64pilot]

I think I must have been reading on Main Sails site when you posted

[a64pilot]

This explains the function of the check ball on a Racor 500 and other good info
http://www.racornews.com/single-post...s-Fuel-Filters

[CarinaPDX]

That ball, and crucially its rubber seat, is a wear item and should be replaced regularly. I would guess in modest use it should be changed every few years. Or about as often as you need to remove the bowl for cleaning? I never had an outright failure but I have removed some dodgy-looking parts. Another good argument for having two Racors in parallel so a quick switch can be done in an emergency.


Greg

[Navicula]

had the exact same thing happen to me but I started to notice I was running out of fuel at anything over 1200 rpms under load.....I bypassed the raycore and everything was well.....then I took the raycore apart and found black crud around this ball bearing

[bwindrope]

Originally Posted by a64pilot

This explains the function of the check ball on a Racor 500 and other good info
Mythbusters: Fuel Filters | Racor News

That's a great article! Thanks for posting. And this is precisely what the Racor guy explained to me about my 200 series. He said the check ball prevents fuel from returning to the tank, as in the 500. And in my case, since my Racor is well above my tank level, that's especially important. I'm actually upgrading my main filter to a 500 series, prompted by this episode and a desire for a dual filtration system so I can switch and go if ever needed. I'll keep my 200 as the lonely back up since it's there already anyway.

[Magic Man]

Originally Posted by a64pilot

This explains the function of the check ball on a Racor 500 and other good info
http://www.racornews.com/single-post...s-Fuel-Filters

Logged in here just to say THANK YOU! That info was very helpful.

Thing is, the dang install instructions for the 75500MAX unit that I have specifically says to install a check valve that opens at .5 PSI or less when tank is beneath Racor, as mine is.

I'm not sure why this is, when the Mythbusters piece clearly explains that the check ball already included in the centrifuge assembly serves this very purpose - keeping fuel from draining back into tank once engine/transfer pump is off and thus loosing prime:

Quote: The engineers put it there to prevent fuel from draining out of the filter and back into the supply line when the engine is shut off. The flow of fuel back toward the tank pushes the ball into a seat, acting as a check valve to stop the flow. In some applications, such as when the filter has been installed below the tank pick up, this back flow would not be a concern. But in many applications the filter can be at the high point, and fuel running back to the tank can easily lead to a loss of prime.

Screenshots HERE