Air Bubbles in the Return Jets. My Fault?

[matt4x4]

Your leak is likely between the skimmer and the pump (suction side not pressure side).
Have you checked for a vortex in your skimmer, sometimes all it is is slightly lower water levels allowing some air in.
You may also have a leak in your pipes anywhere before the pump or even the pump lid gasket could require some lube.
Outside of those areas, it's highly unlikely you'd suck air anywhere post pump, instead you'd be squirting water.
I doubt you're damaging anything with some air going through the system.

[Poolsean]

Well pointed out Matt. Air being returned to the pool is always a suction side problem. Any leaks or breaks in the line after the pump is all pressurized and will result in water leaking/squirting out.

Instead of the shaving cream, use a dish towel, well soaked with water. Take the towel and wrap it around your glue joints, valves, fittings, etc. individually. When you see the bubbles in your pump pot go away, you've found your leak.
Do you have a suction side pool cleaner? Check your hoses.

Are you loosing water when the pump is off? You may have a leak below ground level. You can usually spot this by an unusual damp area in your yard, between the pool and your equipment.

[ccostan]

Thank you everyone for the great replies. I did just replace the Pumps lid rubber seal but did not put any lube on it so I will try that. Unfortunately, there is not much above ground piping between the pump and the skimmers. (Although since I see air even when I switch from skimmers to Main Drain - It is probably somewhere from that y switch to the pump right?) That section is all expose and I will try the towel trick to see if I can make the bubbles disappear from the lid of the pump. I'll keep everyone posted.

Thanks again for the suggestions.

CARLO.

[anotherpyr]

Funny that this post should appear when it did. I just spent this morning solving this very problem.

Lubed the gasket on the pump where you access the basket. - bubbles
Checked the tightness of all the fitting on the plumping coming into the pump - bubbles
Replaced the Teflon tape on the fittings to and from the pump - no bubbles

I think the real cause was the intake fitting wasn't tight. I think over time the installing and removing of the pump each winter loosened it.