How to fix a leaky plumbing valve that doesn't fit a new faucet
Non-standard valve connections often fail to sit flush with new faucet lines, and older diverter stems may require specific replacement washers. Mismatched sizing prevents a proper watertight seal, forcing you to replace incompatible components or track down exact-fit washers.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1using two wrenches to loosen and remove old nuts
- 2replacing the antique valve with a modern quarter-turn stop
- 3reusing the old compression nut if the thread pattern matches
- 4Guessing based on visual appearance of the cartridge or consulting plumbing forums.
- 5Taking out the cap to clean sediments
- 6Adjusting the water level
- 7Aligning and wiggling the cap until it stops leaking
- 8Replacing the entire fill valve
- 9Calling the city to shut off the water at the city-owned shutoff valve
- 10Replacing the valve or setting a new washer or stem in it
- 11trying a sharkbite valve
- 12soldering a male adapter onto the pipe and threading a female threaded shut off
- 13removing the escutcheon cover plate to gain extra room for cutting
- 14Replacing the fill valve entirely instead of attempting a hit-or-miss repair since they are inexpensive.
- 15Hire a professional plumber to handle the valve replacement and any necessary couplings.
- 16Opening the valve fully and backing it off 1/8 turn
- 17Replacing the entire valve with a new ball valve
- 18Taking the old cartridge to a supplier to match and replace it
- 19Hiring a plumber to turn off the water and extend the line
- 20Removing the top nut of the metal piping and screwing on a steel braided line without replacing the angle stop
- 21Getting an initial plumber inspection of the crawl space to map existing lines
- 22Checking for corrosion, leaks, galvanized sections, and water quality
- 23Gathering multiple quotes and asking about permits and access
- 24Considering PEX as a more practical choice in crawl spaces to manage costs
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“So the valve isn’t sitting flush on the connector to the faucet, meaning I gotta replace it.”source ↗
“Need help identifying this shower valve.”source ↗
“Thus is under the kitchen sink. I think I'll hire a plumber to replace the valve.”source ↗
“I have to eventually replace all the pipes run in my house they are 70+ year old copper I think. How do I know what is a good place to work with and what type of pipe to go with.”source ↗
“My toilet has a flapper valve system, and the water is flowing out from the sides of the Fluidmaster valve cap.”source ↗
“I tried taking out the cap and cleaning the sediments, as well as adjusting the water level. How can I tell whether the cap is not put on correctly vs the cap needing replacement?”source ↗
“So I FINALLY got this out of the wall. I *think* I just need a washer on the end of this diverter stem. But my question, I guess is really a two parter: 1) am I right? And 2) how do I know what size washer to get?”source ↗
“My only issue is the knob before the meter doesn't fully stop the flow”source ↗
“If I cut at the indent, will there be enough room for install?”source ↗
“This valve only rotates clock wise about 180 degrees and doesn’t shut off the cold water.”source ↗
“And I couldn’t move it past that and also it doesn’t rotate counter clockwise either.”source ↗
“Any more pressure, I fear it will break apart.”source ↗
“I am just trying to turn off the water to install RO.”source ↗
“Please tell me what needs replacing?”source ↗
“Is this crimped on? Or can I pull it off and replace with a push to connect shark bite?”source ↗
“It's 25 years old and the whole bathroom is getting redone, figured might as well replace it and attach a steel braided hose to the new toilet”source ↗
“I live in a condo so there is no access from below...what you see here is what's available, rest of it is under concrete.”source ↗
“Is that my only option? Or can I remove the top nut of the metal piping and screw on a steel braided line without messing with the angle stop?”source ↗
“He quoted us for both but unfortunately couldn’t afford either. Trying to make it financially possible and start looking”source ↗
“I'm trying to install a new compression quarter turn valve on toilet line but as you can see, half of it has been crimped from the ferrule ring stuck to it.”source ↗
“If i cut off the section that is crimped, will i still have enough room to install the new valve?”source ↗
“I tried putting a sharkbite valve on and it stayed stuck on, but when I turn on house water, water shot out from the connection.”source ↗
Where this came up
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