[minorhero]

I picked up a pre-owned HW-302 off of craigslist last week. I was initially really pleased b/c it was really clean, well-cared for, gaskets & o-rings were soft... and it came CHEAP!
BUT, as soon as I got it set up and pumping water, it started leaking at the latches. I did a lot of reading & YouTube watching and realized this is a fairly common leak for these canisters. I just can't figure out how to fix it! I assumed that the water was overflowing from the quick release valves and ending up inside the lid, so I checked (and replaced) the o-rings on the quick-release valve stems, even added some plumbers tape. That connection is SNUG now. But something is still leaking! The screws holding the lid together are super tight and I haven't been able to open it up to see what's going on inside.
When I empty all the tubing and start it fresh, it doesn't leak until the water gets to the output line. I'm at a loss and don't know what else to try! Has anyone else solved this?

Get some Vaseline and rub it liberally on the main gasket that goes around the lid. This will likely solve the issue.

 

[minorhero]

I hadn't tried that initially because it wasn't leaking on all sides, but for the sake of elimination I went ahead with that test. I made sure the lid was totally emptied of water, the hoses were drained, and there wasn't enough water in the canister to push through when sealing the lid. I reattached everything, pumped the siphon once, and waited for the water to get through. It made it to the output and held for about 15 seconds before it started leaking again. It's only leaking out of the handle closest to the disconnect valves, and it's happening whenever the pump is primed, even if it's not plugged in.
Any other options to try?

Is this a continious leaking or is it by any chance only when it first starts? Most canister filters (including these) will get rid of excess water that overflows the lid by coming out the side like you describe. If it keeps doing it as a constant stream then clearly that's not it. But if there is only a few drips and then it tapers off that would explain it.

Otherwise, unfortunately I'd say you have a bad gasket or a cracked piece of plastic somewhere.