I have a leaky cold water valve in my laundry room. It is a gate valve with a similar set up to This post (although older and with a lot of scaling). I did some research and decided to buy some 5/32 inch valve packing to re-pack the valve. I cleaned the old packing out, scraped the scaling off of the nut, wrapped the packing around the stem 2 times and tightened the nut down until it stopped leaking. I then decided to test it with a load of laundry. Of course, at this point it started leaking slowly again.
This has led me to a question which I haven't been able to find the answer to online:
The valve leaked whether it was open, closed or somewhere in between. Does this suggest that the issue is related to the washer or o-ring located at the bottom of the stem rather than the packing nut itself?
I'd hate to call a plumber, only to learn that I hadn't packed the nut properly but replacing the stem is above my pay grade. Any input is greatly appreciated!
Best Answer
Is this the cutoff valve for the cold water supply to the washing machine? Does it take several turns to go from closed to full open on the stop?
If, when the valve is closed, it leaks continuously around the stem, then the plastic washer at the bottom of the stem needs replacing. One has to remove the stem to do this. Some of the valves of this type use the packing nut to cover the interior and other valves have a separate screw cover. These latter can be stuck in place, but if not stuck this is a standard maintenance procedure.
With the stem out to change the washer, one inspects the brass seat in the valve body. If the sealing surface is compromised, then it should be replaced. However, a valve in cut-off service for a washing machine is hardly ever cycled so the seat is probably OK.