Racor primary fuel filter priming

BlueJasper

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Hi, as the boat is new to me I drained some fuel off the primary filter to see if there was any crud in there. I then opened the bleed screw and started pumping the priming button on the filter but I couldn't get any fuel out of the bleed screw. Engine is a Cummins QSB6.7. The tank is lower than the filter if that helps.

Have I missed something obvious here or do I just need to pump longer and will it run OK in this state or will it ultimately stall?
 
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Portofino

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If it’s on the engine turn on the ignition……..they sometimes have electronic fuel valves ( solenoid s) that’s how it stops .

Q 2 - it will run , but stutter and run rough for a few secs as the air ( if any ? ) works through.
 

BlueJasper

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Thanks, but it's the primary and not on the engine. I can see the feed going back to the tank with a manual shutoff valve.
 

BB1

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Hi, as the boat is new to me I drained some fuel off the primary filter to see if there was any crud in there. I then opened the bleed screw and started pumping the priming button on the filter but I couldn't get any fuel out of the bleed screw. Engine is a Cummins QSB6.7. The tank is lower than the filter if that helps.

Have I missed something obvious here or do I just need to pump longer and will it run OK in this state or will it ultimately stall?
If your pumping the engine pump the Racor is on the suction side so you will suck air into the Racor
 

BlueJasper

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I think I may know what the problem is. I did not close the fuel shut off to start with, so I'm guessing when I took the bleed screw out all the fuel in the line to the filter drained back into the tank.

So if I start the engine for a minute or so, turn it off, close the fuel valve then open the bleed screw and prime it, I should see fuel exit the bleed screw?

Does this sound right or am I just an idiot?

Thanks.
 

QBhoy

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Is the primer not after the primary usually ? You’ll just be sucking air from the vent if so. Usually need to bleed at the secondary with that side closed and sealed.
 

BlueJasper

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Thanks Ben, buts its the design in the vid posted by ChromeDome. Exact same set up. Just concerned that I leave my berth and it cuts out. On a separate note, any recommendations for a cummins engineer in Yarmouth. Service due in new year.

Cheers.
 

Plum

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I think I may know what the problem is. I did not close the fuel shut off to start with, so I'm guessing when I took the bleed screw out all the fuel in the line to the filter drained back into the tank.

So if I start the engine for a minute or so, turn it off, close the fuel valve then open the bleed screw and prime it, I should see fuel exit the bleed screw?

Does this sound right or am I just an idiot?

Thanks.
Does not sound right to me.
You said "if I start the engine for a minute or so" so that means the engine runs ok. So what is the problem?
You said "close the fuel valve then open the bleed screw and prime it, I should see fuel exit the bleed screw?" no, trying to prime with the fuel valve closed will achieve nothing, you will not be bringing and more fuel out of the tank, but why are you trying to prime/bleed if the engine runs ok?

www.solocoastalsailing.co.uk
 

BlueJasper

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The pipe run from the primary to secondary filter is about 1.5 metres , so plenty of fuel to start the engine before the air I have introduced into the system hits the engine.
 

PaulRainbow

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The pipe run from the primary to secondary filter is about 1.5 metres , so plenty of fuel to start the engine before the air I have introduced into the system hits the engine.

Close the bleed nipple, pump the hand pump a few times until it gets hard to pump, start the engine and run for a few minuts at fast idle.
 

BlueJasper

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Just an update, I topped up the filter through the bleed nut, but the hand pump didn't stiffen up, so I guess the diaphragm is knackered. Anyway, took it for a spin and all is good!
 
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