Compression joint leak hassle.

[axzed]

Hi all.
I have a leak that I just can't cure.
My mains stopcock is in the concrete floor in a 9x9" hole forcing me to use a tap spanner
It decided to leak from below the input comp. nut.
There is hardly any clearance to drop the nut down to get behind what may be an olive or a flange.
After a few futile attempts I noticed the first few threads on the tap were split.
I dug out an old one, unsiezed it and greased it up.
I have tried PTF & Bossand even fibre & rubber washers!
I am tightening as much as I can but it keeps slipping off, though I reckon I applied plenty of torque.
A simple problem but I have made 10 or more attempts!
Am I missing something?
What is the basic principle with these?
If it was an olive and no danger of disrupting the lead seal, I would be tempted to tap it up.
If I could get behing the olive, I would pack it with TPF. (I have tried this with tweezers)
HELP PLZ

 

[Puddle]

Well you could try this and that but you are not going to get a joint you can trust even if you stop leak and make tight joint for now,you are looking for an easy way out but sometimes there is not one,get your hammer and chisel out and make a bigger area around joint and redo as required,removing olive and if pipe ok fit new or cut back pipe end if damaged to much by over tightened olive and redo from there

 

[axzed]

Thanks.
So you are saying that the seal is the olive/tap joint & not the nut/olive?
Can it be, & what if it is a flange?
Regardless of the working space I can't see how I can prise the olive off as the nut will not back off enough.
How delicate is the lead to copper joint?
cheers.

 

[WHPES]

Remove the nut and olive. As stated you may need to enlarge the area in the concrete.

Sometimes fittings have a different length of pipe sticking out past the olive and if the olive has stuck on the pipe that may be your problem.

The seal is made between the olive and the chamfered part on the body of the tap. A couple of turns of PTFE around the olive will sometimes help.

 

[axzed]

THANKS
" different length of pipe". That's why I wanted to tap the olive up a little.
So I take it, it ain't gonna be anything other than an olive?
Thanks for the 'seal' enlightenment which becomes obvious if it is discernable as a convex olive edge - my vision is sad.
I never known people so eager to whip out their tools and start banging away.
Ta.

 

[WHPES]

The thing you've got to remember is that us pros have power chisels on our breaker drills and it takes no time at all to open up a hole in masonry, whereas if all you've got is a hammer and chisel, then you're going to get a good workout!

 

[stevetheplumber]

if its an underground stopcock it will not be an olive but a union of some sort most probably with a leather washer
if you can run the nut back you could try ptfe or ls or both doubt if youll change it in a 9x9 hole but you might be lucky and pull it up enough to get valve out

 

[axzed]

Sheesh, bach to square one.
So, is the seal the rear of the nut against the union flange?
As I said, I tried inserting PTF with tweezers and Boss to no avail.
Should the washer be in the same gap and is now irreplaceable?
"you might be lucky and pull it up enough to get valve out" er, ? You lost me there 'valve'. Pull what up? Please explain.
I guessed the hole dimensions. I was correct....for the trap door cover rebate,..... but not for the actual well....7x7!!!

I do have a Kango, put not a 'power chisel' of which, I've never heard.

 

[WHPES]

Laymans speak for a Kango.

 

[axzed]

Hi again.
I am now confused and seemingly left with no other option than to repeat that which I was originally attempting.
Please answer my questions and confirm any correct diagnosis.
Is it a union?
"So, is the seal made by the rear of the nut against the union flange?
As I said, I tried inserting PTF with tweezers and Boss to no avail.
Should the washer be in the same gap and isit now irreplaceable?
So I just add more PTFE?
Can I use an alternative?
THANKS

 

[charitynjw]

"How delicate is the lead to copper joint?"

Could you describe this?

& is incoming mains pipe lead?

 

[axzed]

Hi, Yes

 

[WHPES]

Post a photo. You know the old saying "a picture says a thousand words"

 

[axzed]

OK - Tuesday.
But what is the critical seal for a union joint?

 

[WHPES]

We'll wait until you've posted a photo otherwise we may be advising you wrongly as it's not completely clear from your description.

If you are trying to get a new joint onto a lead pipe, the only way is to cut back the lead pipe to it being sound and fit a Philmac universal fitting or a leadlock.