Leaking under sink waste pipe

[d4rkcell]

So under my sink its pretty straight forward there is a U-bend like trap that connects to a 90 degree fitting which at one end screws onto the U bend and the other end its a bit different.

The other end has a screw type fitting but the pipe that goes out to the drain is smaller and has no thread on it so it sort of slots over a smaller ring of the internal pipe work and then the circular plastic screw cap/head screws onto the internal pipe work.

The problem is i have a bit of a leak at this joint, even then the screw end is tightened as far as it will go the outside pipe can slide and move in/out (though to get it completely out would take a good pull).

I took it all to pieces before the house gets busy this morning and the rubber seals look fine (this pipework is only 6 months old so dont think anything has perished).

Any ideas? It certainly seems like something I should be able to fix DIY, would PTFE tape help? I am not so sure it would. I can take it all out again and take a picture if need be, for now though there's a bucket underneath so we can still use the sink.

Any advice appreciated!

 

[Burnerman]

Picture please, if you will......PTFE isn't the repair material here.
John

 

[PrenticeBoyofDerry]

This sounds like a normal configuration, if I am imaging it correctly, but picture will help. If the joint is leaking it either sounds like the waste pipe is not fully in to the joint, the seal needs replacing or the seal is not sitting correctly when engaging the pipe.
The first thing to do would be to strip the joint down, make sure there is no debris prevent a good seal within the joint,
Some compression joints are different to others, so worth checking out the seals, I would normally expect a plastic sealing ring and a rubber washer. They should be placed over the waste pipe as so:
Plastic threaded nut, plastic ring seal, rubber washer. The washer needs to be placed so it sits inside the fitting when tightened, you will see that washer is concaved at one end, this sits inside the part you are tightening the nut to.

 

[d4rkcell]

Thanks fellas here are the pictures. I took the offending part out before taking the pictures to get a better look at it. It is brand new propper mcalpine stuff.

Here are the photos, any suggestions on a fix, I could understand if the rubber was knackered or perished but it all looks sound. I will say this the grey pipe seems to be at an ever so slight angle. This has been fine for 7 months just started leaking recently no idea why?

First photo, notice the grey pipe this is where the right angle joint connects, this grey pipe runs to the outside

Here are a few photos of the offending fixture.

Sorry if these photos are massive!

I accidently took a video of it put together which is about 1 second long, let me know if you need a picture of it all assembled together.

 

[d4rkcell]

I have just been mucking about with this and it seems like the fitting can easily be pulled off the grey pipe without even loosening the screw fitting thats meant to hold it in place.

 

[Madrab]

OK, there's your problem, the sealing rubber ring was pushed into the fitting.

In this order place onto the grey pipe, the plastic nut, then the red washer then the black rubber washer onto the pipe by a few inches. The rubber washer has a fluted end and a flat end, have the fluted end facing towards the end of the pipe/fitting.
Offer up the white fitting, and push it onto the grey pipe til it's all the way in. Then slide the rubber washer and nut onto the trap fitting and tighten it till it starts to firm up. Line the other end onto the trap and tighten that fitting all the way up, then tighten the grey end fully.

Shouldn't get any movement after that.

 

[Bosswhite]

It looks like the white fitting of the washing machine/dishwaser ( Blue pipe/white fitting) is pressing against the waste fitting not allowing it to fit correctly

 

[d4rkcell]

@Madrab i followed your instructions (see links to pictures) the difference between the pictures and the final fix was i moved the rubber washer further back on the grow pipe rather than right on the end. Previous attempts to fix have resulted in a drip after about 10 minutes, i did this 10 minutes ago and have emptied two full sinks through and its dry so thank you for your guidance, it seems to have worked for now (touch wood). I wonder what caused the washer to get pressed so far into the fitting? Would it be worth buying another washer and forcing this into the fixing to prevent the other one from slipping back?

http://imgur.com/1EHwQqq
http://imgur.com/C8dwLM5
http://imgur.com/lFna7Sc

@Bosswhite I am not expert by any means, i work in I.T. so when it comes to these sorts of things I largely wing it or put my entire trust in a tradesperson. The kitchen was fitted 7 months ago and when it completed i did think the pipework looked little busy if not forced into position. The washing machine fitting does kind of "sit" on the connection but it can easily be lifted out of the way (there is quite a bit of play in the pipes). I don't think it makes that much difference once the waste nut is fully tightened (i could be wrong though). I guess if it does turn out to be this causing the fitting to loosen or not tighten properly then i will re-call the person who installed it.

Thanks again fellas!

 

[Madrab]

I think what has happened is that someone has installed the trap fitting onto the grey waste pipe without removing the nut and washer and fitting it over the pipe first, before pushing into the fitting. Seen that many times before.

As long as when you tightened the white nut and the fitting on the grey pipe does not move now, then you're good to go.

 

[d4rkcell]

too many tradespeople out there doing things the wrong way, can't understand what's to gain by not unscrewing the nut? 1 minute? Cheers mate!