I'm Baffled - Can't Stop Leak in Tub

I have a Delta roman tub faucet that has a leak under the tub that I can't stop. The leak is apparently from the spout. Leaks if I run either the hot or cold water; leaks if I let it drain or if I close the stopper. It has a hand held sprayer with a diverter valve built into the valve for the spout. If I activate the diverter the leak stops. The valve is a Delta 4707 and the diverter is built in the valve for the spout. When the diverter is activated the water travels to within an inch or two of the spout before it is diverted and the leak stops. This lead me to believe the oring was defective in the spout or the spout was damaged but I replaced the oring and the contact surface inside the spout looks perfect. I tried a thicker oring (same ID) and it got worse, I tried a thin line of plumber's putty in the spout to contact the oring but no change in the leak. I also confirmed the valve is installed properly in the tub. Nothing changed on the faucet but it just started leaking this week.

Did I mention that the tub is on two exterior brick walls and the other two sides are tile with no access panels. Not wanting to tear out any of these to repair the leak.

Anyone experienced this type of leak? Faucet is 11 years old.

cowtown said:

I have a Delta roman tub faucet that has a leak under the tub that I can't stop. The leak is apparently from the spout. Leaks if I run either the hot or cold water; leaks if I let it drain or if I close the stopper. It has a hand held sprayer with a diverter valve built into the valve for the spout. If I activate the diverter the leak stops. The valve is a Delta 4707 and the diverter is built in the valve for the spout. When the diverter is activated the water travels to within an inch or two of the spout before it is diverted and the leak stops. This lead me to believe the oring was defective in the spout or the spout was damaged but I replaced the oring and the contact surface inside the spout looks perfect. I tried a thicker oring (same ID) and it got worse, I tried a thin line of plumber's putty in the spout to contact the oring but no change in the leak. I also confirmed the valve is installed properly in the tub. Nothing changed on the faucet but it just started leaking this week.

Did I mention that the tub is on two exterior brick walls and the other two sides are tile with no access panels. Not wanting to tear out any of these to repair the leak.

Anyone experienced this type of leak? Faucet is 11 years old.

Click to expand...

you said '' leaks if I let it drain or if I close the stopper. ''

this tells a story, it is the drain not the valve,
and because it leaks when the stoppe is closed
tells me it is leaking at the tub flange



you need to unscrew the flange, repuddy it pipe dope the threads , inspect the washer that is under the tub [shoe washer]
and put it back in

then, you may have a leak in the hose going to the hand held
cause it sounds like 2 leaks
if it is.
i suggest, cutting a hole in the wall. outside, installing an access door
should have been one to begin with

I probably didn't explain it very well but there is no leak if I use the hand sprayer. We can fill the tub using the sprayer, take a bath and drain the tub without a drop of water leaking, but if we let the water pass through the spout then it leaks under the tub.

Is this what he tub spout is screwed onto. Is that attached to the copper coming out of wall or a solid brass pipe nipple.

Is the diverter on the tub spout or built into the valve. does it leak if you remove the tub spout from the adapter?

Spout attaches to center valve. Valve has an oring (shown in 2nd photo with test cap removed) and the spout has a hex set screw. Appears to be leaking at the spout because if the water is diverted to the sprayer it does not leak. As you can see the diverter is built into the center valve just below the spout.

cowtown said:

View attachment 15421

View attachment 15422

Spout attaches to center valve. Valve has an oring (shown in 2nd photo with test cap removed) and the spout has a hex set screw. Appears to be leaking at the spout because if the water is diverted to the sprayer it does not leak. As you can see the diverter is built into the center valve just below the spout.

Click to expand...

Can you carefully remove the o-ring from the rough in and observe the o-ring groove? BE CAREFUL WHEN DOING THIS TO NOT SLIT/CUT O-RING OR DAMAGE O-RING GROOVE! This groove should have a smooth finish. Also, make sure o-ring looks alright when off the rough. Finally, can you take a top-down picture above the rough looking into the brass waterway at where the spout attaches? If this brass waterway is deformed/out of round, the o-ring seal can be compromised. Try and get a pic looking top down into the brass waterway in which the spout attaches.

Finally, without water, can you confirm the rough in o-ring is making contact with the smooth sealing surface within the spout? When placing the spout onto the rough, you should be able to kind of feel if the o-ring is getting compressed on the sealing surface within the spout. Your deck could be too high/rough in too low, which wouldn't allow the o-ring to properly seal.

Thanks, your feedback put me on the right track, or at least I think I found the problem. The spout attaches to the top of the spout/diverter valve and the set screw just rest on the back of that valve body (the copper pipe is connected several inches below at the bottom of the valve). The top of the valve body was slightly deformed down to the oring seat, kind of just out-of-round. It appears that someone used the spout to help themselves out of the tub and since it is a pretty large, long spout it had enough leverage to bend the valve shape. This is the only thing I can guess happened since the spout has not leaked in 11 years. I tried reshaping the top of the valve, new oring, adding teflon tape under the oring, adding silicone in the area around the oring. They all slowed the leak but not by much. Just ordered the new spout/diverter valve and will replace soon and I will update story. The fun part is that there is no access panel (two exterior brick walls and two interior tile walls) so I'm going to have to try to replace the valve from the floor below. There is a reasonable size opening in the subfloor for the drains and lines and I've already had to remove a section of the damaged ceiling on the floor below. Just hoping there is enough opening to do the work. Luckily the plummer that installed the tub did add fittings for screw-on lines so no sweating joints in the space.