In my sailboat with Perkins 4-236, i have a problem with a trapped air bubble at the exit from my Racor 500 filter/water seperator. I have temporarily put clear tubing in line before and after the Racor looking for air bubbles. No bubbles are seen entering into filter. Exiting the filter i see a long(2 to 4 inches)bubble travel into the clear tubing. If this clear tubing is led up the bubble will travel to the top of this tube and still allow fuel to past. This bubble does not seem to travel any appreciable distance down. Once the bubble is at the top of the loop no new bubbles are added to the system. This bubble just moves back and forth.
If the clear tubing is instead led down, the bubble will exit the Racor into the clear tube but stay within a couple of inches of the Racor. The bubble does not travel downhill. I have varied the engine rpm and the bubble still doesn't travel down hill. Fuel does flow around this bubble and the engine runs fine for tests at the dock.
I have tried filling the center tube of Racor to get the bubble to "percolate "out the top before i put the top and handle on the Racor. Same results.
Will this bubble ever travel thru the system and cause problems? Better yet, how do I get rid of the bubble so when I get rid of the temporary clear hoses I have confidence there are no bubbles in the fuel line?
If the clear tubing is instead led down, the bubble will exit the Racor into the clear tube but stay within a couple of inches of the Racor. The bubble does not travel downhill. I have varied the engine rpm and the bubble still doesn't travel down hill. Fuel does flow around this bubble and the engine runs fine for tests at the dock.
I have tried filling the center tube of Racor to get the bubble to "percolate "out the top before i put the top and handle on the Racor. Same results.
Will this bubble ever travel thru the system and cause problems? Better yet, how do I get rid of the bubble so when I get rid of the temporary clear hoses I have confidence there are no bubbles in the fuel line?