Quote:
Originally Posted by funola
I did follow the procedure above pumping approx 150 times (with the updated black priming pump) without success. After clear fuel emerges from the union screw and tightened, you now have a closed system. I don't understand how further pumping will rid any more air and make the check valve chatter. Where is the air suppose to go? What finally did the trick for me was cranking with the check valve out, which got rid of trapped air and got fuel in.
Isn't it kind of ridiculous to have to pump 150 times, lose a quart or more of fuel and make a mess in the process, lose some skin, and to add insult to injury, if you don''t wash off the diesel soaked motor mount, you end up ruining it. There's got to be a better way!
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You do have a closed system. However, the primer pump is designed to force fuel to the IP and pressurize the system. When the pressure gets above a setpoint.........7 psi??...........the check valve opens briefly and allows fuel/air to return to the tank via the return lines. In theory, the check valve will chatter when it does this.
But.........and this is important..........if the primer pump is not up to the task of achieving the setpoint on the check valve, you can pump forever and you won't accomplish anything.
So, your initial question remains a valid one: Does the new style primer pump achieve sufficient pressure to crack the check valve.
You might wish to give this a test. Disconnect the line from the IP to the secondary.........at the secondary.........and pump the primer. If you get fuel from this open line..........the pump is doing it's job and the check valve just does not chatter..........for unknown reasons. If you don't get fuel..........the pump is not capable of cracking the check valve.........which would be very bad news.