Compression fitting won't stop weeping

Discussion in 'Plumbers' Talk' started by Wishidneverstarted, Dec 16, 2018.

  1. Evening,
    Long story however I needed to move my outside tap.
    Cut out old, tee'd into cold feed, soldered in a tee new pipe work with isolating valve, one side of valve is fine, other just won't stop weeping.
    I did it up the same as the other side ie not over tightened it, it wept, gave it another 1/4 turn still the same, keep giving it another 1/4 1/8 of a turn and still weeping yet other side sealed straight away.

    I'm at the point that it's now over tight

    If I undo the nut will the pipe accept another olive or do I need to replace the bit of pipe?
    Am I doing something wrong?

    Cheers
     
  2. chippie244

    chippie244 Super Member

    A bit confused with the soldering and compression joints but undo it and try PTFE or boss white or fernox or a new Olive and see what happens.
     
  3. Allsorts

    Allsorts Super Member

    Annoying when that happens.

    As you suspect, you may have compressed the olive down to its max. If you undo the nut you might find the olive compressed right in to the pipe and impossible to remove.

    What to do? It may be enough to give it a smear of Fernox Hawk or a wrap or two of PTFE tape and do it up again. What caused it? No idea, but possibly a deep scratch on the pipe or olive, or a bit of grit.

    If you want you can try removing the olive and replacing with a new one - this should help as the olive would have been compressed as well as the pipe, so a new olive with give you more meat to play with.

    To remove the olive, if it's well embedded in to the pipe, then use a junior hacksaw gently at an angle on it - go a good half-way in but don't damage the pipe. Insert a flat blade screwdriver in this slot and twist - it should snap.
     
  4. Astramax

    Astramax Super Member

    Probably damaged olive or burr on pipe causing failure to seal correctly, always clean meticulously prior to connection.
     
  5. DIYDave.

    DIYDave. Screwfix Select

    Undo fitting and remove olive and take a look at the pipe where olive sits

    Is pipe slightly crushed (in which case, olive won’t simply slide off)

    Any deep scratches in copper around the olive

    Is pipe fully inserted into compression fitting

    If olive won’t slide off, can try nudging it off by using adjustable wrench just open enough so pipe fits between jaws. Slide wrench along pipe with moderate force so it bashes into olive. Do this several times - should see olive slide along pipe and fall off end. You will need to use a new olive to reassemble

    As above, can try a few wraps of ptfe both under and over the olive, or a ‘paste’

    If pipe has been badly crushed by over tightening, better to cut out and replace that section

    Don’t be tempted to just fudge up threads on fitting with tape. It may hold for a while but its a ticking time bomb :eek:

    The olive creates the seals - not the nut
     
    Allsorts likes this.
  6. Thanks for replies.

    I'll try a bit of Ptfe first then replacement olive if that doesn't steal it,Although as I said think it's over done now anyway so I'll probably end up replacing the bit of pipe

    Cheers
     
  7. seneca

    seneca Screwfix Select

    I think you'll find a bit of ptfe will do the trick!
     
  8. Jimbo

    Jimbo Screwfix Select

    As a fellow DIYer - I always use copper olives and a wrap of the one-wrap (gas) PTFE. Works for me.
     
  9. Heat

    Heat Screwfix Select

    Always best using a smear of paste.
    Using ptfe tape is better than nothing, but it tends to get cut where the olive hits hard against the fitting.
    The paste is a fine sealant and will do a better job.
    Do make sure that the pipes and fittings line up together properly so to make a good joint
     
  10. ajohn

    ajohn Screwfix Select

    Copper olives can help a lot especially if jointing compounds aren't used. ;) I no longer get my compression fittings from screwstation due to that. I use a more normal plumbing supplier who agreed not to over charge me. Also bought some copper olives for the screwstation fitting I already had.

    Maybe the side you are having problems with's pipe wasn't well lined up with the valve when you tightened it. Personally I would carry on tightening. There are also some setting jointing compounds about. I'd guess that the best way to use that would be assemble up firmly, leave to set at least a bit and tighten a bit more - if you can.

    Edit - Copper olives - now I have seen them suspect they are red brass. Brass with more copper in it.

    John
    -
     
  11. Heat

    Heat Screwfix Select

    I still find that I come across plenty of compression fittings and valves that use copper olives that are weeping slightly (usually just evidenced by white corrosion on the brass or green on pipe). Paste is essential.
    The problem can be partly due to the cheap quality of the brass fittings.
    Brass olives are actually better than copper in many respects and will seal better on heating pipes long term. Copper can be too soft.
    However, the brass olives are better of a soft brass type and of substantial thickness, - like Conex or Kutterlite.
    Obviously must be copper olives on plastic pipes
     
  12. dinkydo

    dinkydo Screwfix Select

    Some good tips in there, if I could add when you have wrapped some ptfe tape around also add a smear of LSX good stuff in my opinion, also apply some lubricant to the threads silicon grease is good for this
     
  13. just pumps

    just pumps Screwfix Select

    Did someone really say put PTFE tape under an olive?
    Thankfully the op has mentioned replacing that section of pipe.
     
    Heat likes this.
  14. Just to close this off, I had all the bits to replace the pipe and olive so went win that, was very careful about how clean it all was, made sure pipe was fully in the fitting and surprise surprise no leak. Not sure what was wrong with the previous bit of what was new pipe and olive but it's fixed.

    Cheers for the advice
     
  15. DIYDave.

    DIYDave. Screwfix Select


    Ha ha that was me ‘just pumps’

    Yeah it’s a bodge .......
    Yeah I’m an annoying diy’er.......
    Yeah it should be seen as a temp. fix
    Yeah it worked for me .....

    Discovered a leak on a 15mm compression fitting at home, took apart, pipe had been crushed under olive, water was passing under the olive (or so I assume)

    Had to use materials to hand so cut off olive, tape UNDER (yes) new olive and over olive - fitting now holding

    This may well have remained water tight for ever, who knows but at a later date, cut out pipe section and replaced, using end feed coupler

    I also stated in same post that ‘if’ pipe crushed under olive due to over tightening, best option is to cut out and replace

    Sometimes a bodge is all we can do with time and materials to hand. As long as it works and is considered as a temporary fix, then all good eh :)

    Yes I know that some olives are tighter on some pipe than others, so in some cases, you couldn’t slip olive over tape but, I’m talking about a few wraps here, not like 15 or more
     
    WillyEckerslike and Heat like this.

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