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How to Replace a Leaky Toilet Water Shutoff Valve – Part 3

Bob Jackson
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by Bob Jackson

How to Replace a Leaky Toilet Water Shutoff Valve – clean the copper water supply tube and install the new 1/4 turn shutoff valve.

This project is continued from How to Replace a Leaky Toilet Water Shutoff Valve – Part 2.

Here’s the 1/2 inch cold water copper pipe in the bathroom floor after removing the old water shutoff valve. The oxidation and build-up of minerals must be cleaned before the new 1/4 stop valve is installed:

Toilet Water Stop Valve Installation: 1/2 inch Copper Pipe Stub
Toilet Water Stop Valve Installation: 1/2 inch Copper Pipe Stub

The Oatey 4-in-1 brush does a great job of cleaning the copper pipe stub. Just wiggle and rotate the brush back and forth on the pipe:

Water Stop Valve Installation: Clean the Pipe Stub with Oatey 4-in-1 Brush
Water Stop Valve Installation: Clean the Pipe Stub with Oatey 4-in-1 Brush

Bathroom Water Shutoff Valve Installation

The new Brasscraft 1/4 Stop Valve, compression nut and brass sleeve are ready for installation on the cleaned 1/2 inch copper pipe. Notice the deep pocket in the stop valve to receive the pipe stub:

1/4 Turn Water Stop Valve Installation: New Valve and Cleaned Pipe
1/4 Turn Water Stop Valve Installation: New Valve and Cleaned Pipe

Slide the compression nut over the pipe stub with the threads facing the end of the pipe followed by the brass compression ring:

Water Stop Valve Installation: Compression Nut and Brass Sleeve
Water Stop Valve Installation: Compression Nut and Brass Sleeve

Set the stop valve body on the end of the copper pipe and press until the valve is fully seated. Rotate the valve body so the valve handle is easy to reach:

Brasscraft 1/4 Water Stop Valve Installation
Brasscraft 1/4 Water Stop Valve Installation

Tighten the compression nut on the stop valve by hand. Then place a wrench on the valve body to hold it steady and tighten the compression nut with a second wrench. Tighten the nut a 1/2 turn after you feel it seat or bite against the brass sleeve. Do not over tighten the nut to avoid cracking the valve body or nut. You can always tighten the nut slightly if there’s a water leak:

Bathroom Water Stop Valve Installation: Tighten the Compression Nut
Bathroom Water Stop Valve Installation: Tighten the Compression Nut

The new water shutoff valve is installed on the 1/2 copper pipe. Almost done!

Water Stop Valve Installed on 1/2 inch Copper Pipe
Water Stop Valve Installed on 1/2 inch Copper Pipe

I really like the steel braided Brasscraft Speedi Plumb PLUS Toilet Connector hose which has a 3/8 inch compression nut and o-ring built into the hose. Unscrew the 3/8 inch compression nut included with the new stop valve. Set the valve nut and brass sleeve aside. Note: You may need these if your toilet connector hose is different!

Water Stop Valve and Brasscraft Speedi Plumb PLUS Toilet Connector
Water Stop Valve and Brasscraft Speedi Plumb PLUS Toilet Connector

Attach the toilet connector hose to the stop valve and tighten with a wrench. Do not over tighten.

Water Stop Valve: Attach the Toilet Connector Hose
Water Stop Valve: Attach the Toilet Connector Hose

View of the new 1/4 turn toilet water stop valve and connector hose. Time to turn on the water at the water meter and check for leaks.

Water Stop Valve Replacement and Toilet Connector Hose
Water Stop Valve Replacement and Toilet Connector Hose

Turn on the Water and Check for Leaks

Turn On the water at the water meter. Wait for the air in the pipes to clear and close the faucets that were opened previously to drain the house water pipes.

Turn On the water stop valve to refill the toilet tank. Check the valve connections for leaks. Tighten the compression nuts a 1/4 turn if you find a leak. Toilet paper is an excellent tell-tale for finding small and slow leaks because wet spots show very well.

Water Stop Valve Replacement: Leak Check
Water Stop Valve Replacement: Leak Check

Hope this helps,

Bob Jackson

1/2 copper pipeBrassCraft 1/4 Turn Stop Valvehow to install a water shutoff valveOatey 4-in-1 Brushtoilet connector hose
Bob Jackson
Bob Jackson
Technology product manager by day and a prolific handyman in the evenings and over the weekends. Bob was the founder of the original Handyman How To website and that tradition continues on this site with excellent new handyman content into the future.
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