The trailer which had the leak. The tubing that feeds the kitchen sink is grey. The two shutffs under the sink look like quarter turn valves (I didn't touch them) or possibly globe valves. More likely globe valves.
The grey tubing attaches to the faucet with crimp connectors, somewhat similar to what I'd expect to see on an automotive small hose line. It's not flare, and it's not compression. And it's double definitely not white PVC.
How would I know if it's that polybutylene that's supposed to be replaced? She says she checked, and it's past the date of the warranty recall.
Is this one of those "rip it out and start over, and it's going to cost a bundle" moments?
The leak was the fitting on the bottom of the kitchen sink faucet. A couple minutes with a Channelock did the job, though I was really wishing for the basin wrench I had at home.