Thank you Garry and Hersbird,
It's been six days now since my planned first trip was cancelled because of the leak. I've spent some hours diagramming the plumbing and studying, online, and at Lowes and Home Depot all the different type of connectors.
The problem is access through the small city water cutout or from inside, through the small space between the hot water heater and the inside wall. I can't fit my hand into either space! Poor engineering on Hi-Lo's part. It would be a trivial 15 minute job if there were access. I may have to take off the outside fiberglass wall or the inside wall to get access.
There are two T connectors at floor level in that space I can see from inside, but can't reach, one from the pump to a second tee (and on to the cold water faucets) on one side and on the other side to the hot water tank input. The second tee is a couple inches further back, also on the floor, and 18"under the city water cutout. It routes the city water to both the cold water faucets and the the hot water tank through the first tee.
Hi-Lo has left no slack between these connections so I can't pull the tube and leaking connector even a 1/2 inch toward the cutout . If I cut pull it a little ways out of the cutout I could easily replace the connector. If I could disconnect even a single connector from one of the tees, I could probably pull the city water tube a couple of inches and then repair, but I can't reach the tees PLUS all of them seem to be glued to the 1/2 inch including the one at the city water cutout which I have tried many times to remove.
So I finally cut the glued-on tubing inside the city water cutout at just bellow the 1/2" CTS to 1/2" NPS female swivel and am left with the open 1/2" tube below the level of the cutout. I don't know if any of the tubing or connectors are PEX.
Gary, they don't look like the Pex connectors sold today at Lowes and Home Depot where I have bought about $20 of connectors plus tubing,hoping I might find a combination that works. Hersbird, I love the idea of those push-on fittings because I canreach in the cutout far enough to do that, but the NPS side would be too low in the cutout to connect to the city water flange. So would anything else I've found so I remain stymied at the as to my next step!