Air In Lines

[OhioJL]

I have an in ground pool and when I opened it I have air in the strainer trap and air in the the return lines. How should I go about finding the source of the air? The pressure does not look all that bad in the lines, just have air in them. I have replaced the O ring at the stainer basket and looked for leaks but don't see any. I have a 3/4 HP stra rite dura glass pump.

[muss08]

Are you losing any water? If you have air in the lines then you most likely have a suction side leak. This is all the plumbing that leads to the pump. Other issues could be that your water level is not high enough and the skimmers are sucking in air. What size pipe leads to the pump and how long of a straight run of pipe is there before the pump? I ask this because there is supposed to be a straight run of pipe before the pump whose length is 5x the pipe diameter. So if its 2 in. pipe leading to the pump then there should be a 10in straight run. Any 90 or 45 degree fittings before this cause turbulence so you could have air because of this.