How to Replace a Leaky Toilet Water Shutoff Valve – remove the old water shutoff valve and saw off the stuck compression nut.
This project is continued from How to Replace a Leaky Toilet Water Shutoff Valve – Part 1.
The 10 year old multi-turn stop valve developed a slow leak at the white valve stem when I turned the water on after replacing a toilet fill valve. I tightened the packing nut a 1/4 turn with wrench, however it continued to leak a drop or two per hour. I decided to replace it with a new Brasscraft 1/4 Turn Ball Stop Valve.
The new 1/4 turn straight stop valve is shown here next to the old multi-turn stop valve:
Water Shutoff Valve Replacement Steps
Shutoff the water to the entire house:
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The water must be shutoff to the entire house before the valve can be replaced.
You can do this at the water meter. This is necessary to prevent high pressure water gushing out of the open copper pipe and flooding the bathroom when the stop valve is removed. - Open the cold water faucets in the kitchen, bathroom or outdoor water hose bib that are lower in elevation than the stop valve in the bathroom.
Why? Because this will relieve the pressure in the cold water pipes AND drain the water out of the pipes that are higher than your stop valve. You don’t want several gallons of water running backwards from the 2nd floor plumbing out of the pipe stub all over the bathroom floor. - Flush the toilet and hold the handle down to drain the toilet tank.
This will minimize the amount of water running down the toilet connector hose when you unscrew it from the stop valve.
Disconnect the Toilet or Faucet Hose
Unscrew the 3/8 inch compression nut on the toilet connector hose with a wrench. The towel is catch the water in the connector hose.
The toilet connector hose is removed from the water valve. Leave the other end of the hose connected to the bottom of the toilet tank:
Remove the Water Valve from the Copper Pipe Stub
Two adjustable wrenches are required to remove the 1/2 inch compression nut on the bottom of the water stop valve. Hold the valve body in place with the top wrench and unscrew the bottom compression nut with the other wrench.
Lift the stop valve off the end of the 1/2 inch copper stub and set it aside:
Water Shutoff Valve: Stuck Compression Sleeve Removal
The water valve compression nut and brass sleeve should slide off the end of the copper pipe stub. The compression nut and sleeve were stuck because the pipe stub had 10 years of oxidation and mineral deposits. As I pulled on the compression nut, it pinched the beveled brass sleeve and wouldn’t budge (that’s the way it’s supported to work). I also didn’t have enough pipe stub coming out of the floor to lower the nut and get at the brass sleeve. I sprayed WD-40 on the compress sleeve but it still wouldn’t budge. I could probably have left the old compression nut and brass sleeve on the pipe stub and installed the new stop valve, but if it leaked I’d have to do the job over again.
My solution? Saw off the compression nut with my Dremel powertool with a metal cutoff wheel.
Cutting off the valve compression nut requires great care to avoid damaging the 1/2 inch copper tube. Notice the 1/8 inch gap between the nut and copper pipe stub? That’s my margin of safety.
I only cut the compression nut threads with the Dremel tool and cutoff wheel. Hold the Dremel tool with both hands and cut a groove in the nut using light pressure. Go slow and check your work. Do not cut through the bottom collar of the compression nut because it rests directly against the copper pipe stub and there is zero clearance. Saw through one side of the nut, rotate the nut 180 degrees and make an identical cut on the opposite side:
Insert the tip of a screwdriver in the groove sawn by the Dremel tool and twist to crack open the compression nut. It took a surprisingly light force (a child could do it) to split the nut in two and it broke apart with a “ping!”. Note two the red lines illustrating where the nut collar was not cut with the Dremel tool.
The brass sleeve remained stuck on the copper pipe stub. I couldn’t cut the sleeve with the Dremel tool because it rested directly on the pipe stub and I would damage the pipe stub.
To remove the brass sleeve:
- I lubricated it thoroughly with WD-40.
- Set the jaws of the adjustable wrench to exactly the width of the 1/2 copper pipe stub so it would catch the bottom of the brass sleeve.
- Levered the adjustable wrench on an improvised fulcrum of two wrenches.
- Important! I set the palm of my hand on the top of the pipe stub to keep it from pulling out of the floor and stressing the plumbing connections, then…
- Smoothly pressed down on the wrench handle to force the brass sleeve off the end of the copper pipe stub.
Success! The brass compression sleeve came off without too much difficulty:
Water Shutoff Valve: Stuck Compression Nut and Sleeve
Here’s a couple of closeups showing how I sawed through the threads of the 1/2 inch stop valve compression nut with the Dremel tool and cutoff wheel, then cracked it open by twisting a screwdriver in the saw groove.
I only sawed through the nut threads. I didn’t saw through the nut collar because I would’ve cut the copper pipe:
Another view of the compression nut interior:
The new 1/4 turn water stop valve is installed in How to Replace a Leaky Toilet Water Shutoff Valve – Part 3.
Thanks for reading,
Bob Jackson
