Lost prime/Deep Well

Just moved into an older house built in 1920. At first it took a couple of times to prime before we got continuous water flow. The old pump would prime and shut off but needed tapped to get to turned on sometimes when water pull was too great or long. Eventually the old pump motor went out and we lost prime. We installed a new 1/2 hp convertible jet pump but still couldn't get prime. Its a deep well we removed the well seal/cap and replaced it as well as the foot valve. It took a couple times but we were able to get running water. The pump never gets above 30 psi, but with the old pump it never ran past that anyways (we even tried an air pump). I ran the washing machine and at first the washer did not kick on the pump. I usually run the kitchen faucet to get it to kick on for the washer. I started to lose water pressure and avoided using water while the washer. When I checked the well had lost prime anyways. Is there anything else to consider before we check for a leak from the house to the well? The problems in the past have seemed to come from the pull from the washer. It was the first time I tried to run water to the washer since the old pump.

Thanks.