The problem with these Check Valves leaking, is that internal "O" ring going bad. The $5.00 can of carb cleaner is NOT going to fix that.
The valve is put together at the Factory with a rolled crimp to hold the cap on. One can grind off the crimp, to lift off the cap, to expose the internal parts like in my picture. BUT... there is no way to put it back together. How does one weld the "cap" back on without heating up that O ring and destroying it. Haven't seen it done yet.
The most practical way to cure a leaking valve is "replacement".
