Thanks all. I've changed the shurflo diaphragm pump, I've changed the screen filter and tightened down the housing, today I swapped out the SS ball valve, I've tightened all the fittings. I'm gonna check my lines again, however a leak in the lines generally shows racing bubbles, which I've had in the past and is an easy diagnosis. I guess I'm gonna have to live with the low vacuum this year and take everything apart in the off season. Don't think its the vacuum gauge as everything else I've witnessed is consistent with low vacuum as compared to previous years. By the way I have a MountainMaple Vacuum system, which worked great in past years. Thanks again for everyone's contribution.