How to test a tub/shower valve body for leaks

[Jdbs3]

Redoing a bathroom tile tub surround. Prior to tiling, I needed to diagnose and locate a previous known tub leak. I opened up the ceiling below, and yes the leak was still there. It appeared to be coming from around the valve body.

I removed all the old tiles around the tub. Now I can't find the leak when just running the water from the faucet into the tub. So the leak is either:

1. the sleeve that has the cam packing, ball, seats and springs (easily fixable), or
2. the 3 copper tubes that come into the back of the sleeve component (not fixable).

NOTE: This is not a cartridge type valve body.

How can I test to assure that it is not one or more of the 3 copper tubes that has possibly a hair-line fracture? I would rather not purchase a new valve body and trim just to assure this.

Thanks

 

[Terry]

You will need to run water in those sections.
You can pressurize the pipe to the shower head by removing the arm and replacing with a nipple and cap.

Do you have access to see what is going on? Removing the plate behind the knob my help.

For locating a leak on a tub/shower, there are several steps. We start low and work ourselves higher as we go.

Does the tub hold water? Pouring water in the tub, and then checking for a leak on the lower drain.
Is it the overflow leaking? Sometimes when kids fill the bathtub higher than the overflow, and the gasket there isn't sealing, that can leak below. I say kids because so often when I get that call, I ask if any kids recently took a bath. Oh yes, yep.
Okay, we're checking the overflow.

Some tub spouts are the cause. When the diverter is pulled up on the tub spout, does water leak into the wall? That's also a common one. A new tub spout is often my cure. I favor the Delta spouts with their weird adapter as that let's me use a pipe nipple or solder onto copper. A good slip spout on copper also works. Moen makes a good one.

Okay, maybe not the tub spout. Is it the caulking around the wall plate and tub spout. You shower with your back to the shower head and the water bounces off your body and onto the wall with the controls. Make sure that has some clear caulking. Yes you can use white too, kind of noticeable though. I can see white caulking from the kitchen it's so obvious.

Is it the shower head? Sometimes those crack over time? I had one condo where the tenant on the third floor was showering with a dangling shower head and arm. Replaced the shower arm and it was all good.

I had one where the shower head was spraying sidewise over the curtain. And they didn't even notice. Weird.

And then the was the one where I asked first if the husband was showering with the sliding doors open. Oh no, he wouldn't do that.
So I cut drywall, opened up ceilings and found nothing. I'm telling you "NOTHING".

A year later I go back, walls patched and painted, I'm there for something else. Did you figure out the shower leak?
Yes, my husband was showering with the slider door open. Dooh!!

 

[Sponsor]

 

[Jadnashua]

Depending on the extent of your remodeling, local codes may require you to upgrade the valve to one meeting current regulations. FWIW, it is often not too economical to leave an old valve in the wall when remodeling as with some of them, it gets harder and harder to find the parts required to make it work when it eventually fails.

A new shower valve would have anti-scald technology, and would make a difference to a home inspector should you want to sell it in the future, too.

 

[hj]

The three tubes are ALWAYS under pressure so if they were cracked it would ALWAYS leak. (and as a sidebar, they ARE repairable.)

 

[hj]

You probably misdiagnosed where the leak was coming from. It could have been at the tub's overflow opening or from around the valve's trim place.