Need help with a toilet supply line repair

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by spta97, Mar 18, 2012.

  1. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    Hi everyone,

    I was looking for some assistance repairing a toilet supply line. I remodeled my bathroom a few years ago and used PEX to replace the bendable copper that was in there before (weaving through the uneven stud spaces).

    As per the plumbing supply place, I terminated the PEX at a 90 degree screwed into a wood backing and put a threaded pipe (satin nickel) with teflon tape similar to this:

    [​IMG]

    Then I screwed compression fit shutoff valve which came as part of the satin nickel set with the thredded pipe. I noticed some rust / green tarninshing on the bottom so it appears I have a veeeery slow leak at the threads (this is after about 3 years):

    [​IMG]

    The back of the baseboard that was there had some mold on it as a result but it was a very minor leak as there was never a drop of water on the floor.

    I would like to repair this without ripping open the wall. My instict would be to remove it, retape the threads, then tighten it back on. My concern is that if I loosen the threads to remove the shut off, I will be loosening the threads on the 90 degree pipe inside the wall. There is really no room to grab the pipe with pliers as you can see from the pic.

    I would have preferred to solder something on but in order to get satin nickle I did not see how that would be possible.

    Any advice would be appreciated!
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,015
    Location:
    New England
    Because the fitting in the wall is 'locked down' by the el, I wouldn't worry about it, unscrew it, and the whole nipple will possibly come out. Put a new coat of pipe dope on both ends, and when you thread things back together, you'll be tightening both the valve (which isn't a compression valve, at least on the nipple end) and the nipple into the fitting in the wall at the same time.
  3. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    Yes - I meant screw down (is what what they are called?) , not compression. My concern with that approach is that once I remove it I will have no way of testing to make sure the connection inside the wall is not leaking. I had it setup with a cap for over month (like the first pic) to make sure there were no leaks. I hate screw down fittings - I have no faith in them at all and I'm kicking myself for using them.

    So say that I take the valve or the entire pipe off - how tight should I put it back on? Can these things snap? I have broken many a thing by putting too much elbow grease behind it :)
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,015
    Location:
    New England
    It's a threaded pipe connection. While it's possible to break a fitting, it really takes a lot of torque to split one unless it's defective.
  5. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York


    Thanks Jadnushua. So I'm trying to think what I did wrong that caused the leak. I doubt it was that I didn't tighten it down enough so I'm thinking it may be I didn't use enough teflon tape.

    That said, I read somewhere that some people use 5 - 6 wraps around threaded connections to prevent such leaks. Is that a good idea?

    My plan is to mark the pipe with a marker to see if it moves as I unscrew the shut off valve. Hopefully it will not (I screwed the pipe down to the elbow by using clamps on the pipe cap and now I recall I got the pipe clamp off without undoing the in-wall part). Then use a generous wrapping of teflon tape and crank it down until it is nice and snug. Then check for leaks and do another full rotation if it does.

    Does that sound like a good plan? The problem is I can't actually see it leaking now (it is dry) so I will not be sure if it is leak-proof for a while.

    Thanks again for the assistance.
  6. mliu

    mliu Member

    Messages:
    101
    Location:
    California
    That may be true for steel pipe fittings, but for brass fittings, it's a whole 'nuther story: a person who does not have the experience to "feel" when it is time to stop torquing, it is all too easy to split a brass fitting, especially if using a large monkey wrench.
  7. mliu

    mliu Member

    Messages:
    101
    Location:
    California
    From your photo, it looks like you got the valve nicely perpendicular with the floor (i.e., the outlet is straight up). It can be difficult to get a threaded connection properly aligned AND properly torqued, especially when using teflon tape as your sealing method. My guess is:
    1. You didn't have enough wraps of tape, or...
    2. You stopped before fully tight in order to get the right alignment, or...
    3. You overshot your position while tightening, and then backed the fitting off a bit to get it aligned just right.

    Your nipple will lose its seal if it's backed out even just a fraction of a turn, especially since you used teflon tape as the sealing mechanism. I would assume the seal will be broken: remove the nipple and re-seal it to be sure. This would be a good time to replace it with a longer nipple so you can get a wrench on it in the future.

    The teflon tape is your big problem. Teflon tape is less messy than pipe dope, but much more "sensitive" to the skill of the person applying it and torquing the pipe. Do yourself a favor and get some Rectorseal No. 5. Apply it to the external threads (only) of your nipple, brushing it into the threads so that they are fully coated.

    Another full rotation is a good way to split your fitting.
  8. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    This is why I prefer electrical over plumbing - everything is exact :)

    Well I won't be using a monkey wrench and I was pretty sure I got the last fitting on snug enough before the breaking point. I tend to use two or three fingers on the wrench when getting toward the end as not to give it too much torque as I have snapped more than my fair share of fittings / bolts / etc. when using my full hand.

    That said, would you think that the leak was caused by not enough teflon tape? Are 5 - 6 wraps the way to go?
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,015
    Location:
    New England
    Too much tape can cause leaks. Pipe threads are tapered and there's a slight difference between the male and female so things end up wedging together. Pipe dope is more maleable and fills in the gaps better than tape, although either works. You don't need quite as much torque to get a proper pipe doped connection as you do with the tape. Plus, the tape, being so smooth, makes it easier to turn and thus overtighten. Some of the threads on pipes these days are not smoothly cut, and the pipe dope seals better than tape. Some use both as sort of a belt and suspender situation.
  10. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    Thanks for the info. I don't know how I could possibly take this off and put the new one inside the wall without ripping the wall open. The pipe is about 4" I think so a good portion of it is recessed in the wall and unless the wall is open I have no way of checking it for leaks.

    The other issue is I do not know of a way to be assured that I have hit the right torque on the fitting. There are no specifications and I am certianly not a plumber with years of experience in the field.

    Also, since the leak is so minor I fear that I will cause more harm then good by messing with it.

    As an alternate, what about putting a bead of silicone around where the leak is?
  11. mliu

    mliu Member

    Messages:
    101
    Location:
    California
    With all due respect, if you're asking this question, then it may be time to call a plumber. There is no sealant that can be applied to the outside of the PRESURRIZED pipe that will effectively and permanently stop a leak.

    No need to rip the wall open. I understand your paranoia of working "blind", but this kind of thing is done all the time. Your biggest mistake in this whole project was the use of teflon tape. As I said before, pipe dope is MUCH more forgiving and virtually foolproof. Just be sure to get the good stuff -- this is not the place to try to save a few pennies.

    As I said before, get a longer nipple so that you have at least 1" protruding from the wall.


    Torque it with moderate force until it will not turn further. If you use good pipe dope, the joint will be sealed.

    Perhaps you should reflect on this statement. Hire a reputable plumber with a written guarantee and then you get peace of mind. And if ever there is a leak in that pipe, they will have to be responsible for it.

    Plumbing is not made of flesh and blood: pipes do not heal themselves. Leaks almost always get worse over time. Even a very small leak can do a LOT of damage. Get it repaired.
  12. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    I was not sugguesting that I stop pressurized water with silicone, rather a leak that is nothing more than a few drops a year. But point taken.
    Thanks - I will check out the pipe dope and have go with that. Working blind is nerve racking though when you do not do this everyday.

    Yes - I will look for one but would prefer to get a solder on shut off valve if I am going to go that route - that way I don't have to worry about the threads on the outside.

    Good advice - thank you.

    The problem is that most of the "tradesmen" in my area are horrible. I have tried "professional" plumbers and electricians and they do shoddy work. That's why I had to teach myself how to do it. Perfect example was when I was doing the bathroom - I called in a plumber to ask about cutting my waste pipe that was now sticking out of the floor. I had this guy and his partner over who sugguested that I install the closet flange over the pipe with the pipe protruding out of it. They actually tried to put the toilet on it the pipe to see if they could get away with it and it was literally resting on the pipe (glad my toilet didn't crack). Can you imagine two licensed plumbers sugguesting that I install something that would create a trap for waste?

    The electrician I hired years ago made a mess out of my panel. And those are just two examples.

    No one takes pride in their work around here - it is all about getting in and out as soon as you can. Trust me, I'm not cheap - I would have gladly paid someone to do a job for me if I found people who did quality work but was forced into learning on my own. Now the more I learn the more I see how people in my area don't do the right thing.

    Agreed.
  13. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,015
    Location:
    New England
    Threaded is fine, don't worry about it. Just get both started, then tighten them both at the same time by turning the valve.
  14. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    I picked up the Rectorseal No. 5 at Lowes yesterday - now I am just looking for a longer threaded pipe in satin nickel.

    I was reading the instructions on the pipe dope and they do not specify cure times - do you have to wait a certain amount of time before putting the pipe back into service or is it ready once you have it installed?
  15. Terry

    Terry Administrator Staff Member

    Messages:
    15,005
    Location:
    Bothell, Washington
    You dope up the nipple and thread it in. Don't wait for it to dry.
  16. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    Thanks Terry. I tried to find the longer pipe nipple online but it was out of stock and the other places cost almost more to ship it than the pipe costs so I'll search locally.
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