Hose size or air leak

[Barry J]

Pool

I have an above ground pool , just started up for the season. I have excessive back pressure coming thru skimmer after I shut off filter. A couple of things are happening. One is my suction hose broke last year, the only extra hose I had was a 1 1/4 size. The old one was a 1 1/2 hose. (i have one ordered and coming in ) but in the mean time have to run the pool. Will that smaller diameter hose from skimmer to pump cause air to come into the system? Or should I look elsewhere. There are air bubbles coming from return after running for awhile. Another thing is a drip coming from the pump drain hole when pump shut off. I bought a new plug with “O” ring and replaced but still drips. I tried loosening it , tightening it, teflon tape, lubrication, everything.
Almost ready to apply some sealant to plug and call it a day, sense I never use it. Could that be my problem or should I just try to change that skimmer to pump hose back to 1 1/2 ?? Also, before anybody ask, it is an above ground, with the system set up below the water line.
Thanks for any help
Barry

[Teapot1]

I think you should change the pipe back to 1 1/2". No it wont cause air in the system but an air leak wiil so that is your issue. As you changed the pipe that is where to look first.

[Barry J]

Actually found that the pump has a hairline crack in a crease that is very hard to find and is right above the drain , so looks like a new pump for me,, shame, just 4 years old

[Teapot1]

Can you search for a new wet end for the pump?