On Thursday, June 15, 2017 at 11:47:28 AM UTC-4, HerHusband wrote:
Sorry to hear that. It's the bad scenario we all agreed can easily
happen when you start trying to fix old plumbing that you have no
or limited access to.

All I wanted to do was replace the tub spout...

I've had a lot of experience with old plumbing at my in-laws house
(galvanized pipe, even worse). I've learned nothing is easy when it comes
to old plumbing.

Given that this is a fixer upper in need of a lot of repairs, I would not
hesitate to use sharkbite if it makes things easier.

Access is going to be the biggest problem.

I won't be able to get back to mom's house for a few days.

Anthony

I just went through a similar evaluation with my shower. It has 25 year
old Hans Grohe faucets. The shower volume had gone down gradually,
getting really noticeable the last year or so. I had cleaned the existing
shower head, no change. Recently I bought a new dual head shower
contraption, where you can use one or the other or both heads at the
same time. No change. I then realized that the water flow out of the
pipe was low. So, what to do? I considered taking the valves apart,
but these fancy Grohe handles do not use screws, they just press fit
on. I figured after all those years, they were not likely to come off
easily, if at all, and there is no way to even pull on them, ie you
can't get a puller type thing on them, etc. And the last thing I needed
was to have to put in new ones, because these still look and work fine,
other than the volume issue.

So, I decided to try blowing it out with the air compressor. I rigged
up a fitting, blew air through the shower pipe and out the tub and
sink fixtures. And voila, I'd say the volume easily doubled. And the
new shower heads now work fine, the flow can support both of them.
I got lucky.