External waste water pipe leaking

[bobski1]

The external waste pipe which runs from the kitchen sink to a drain has begun to leak. Nothing significant but I notice a damp patch from time to time. I've never really had to deal with plastic pipes but am I right to assume it should just twist off or do I need to cut and dismantle?

I'm thinking I just need to buy a new joining piece or do I need to replace more of it?

[smokey mow]

The cap which is a rodding point would just twist off but the connection between the waste and tee will be solvent welded.

[bobski1]

smokey mow said:

The cap which is a rodding point would just twist off but the connection between the waste and tee will be solvent welded.

Okay will give the cap a twist and see if there is anything obviously wrong.

Is there a way to remove the tee without having to cut it off? The waste coming out the house doesn't seem to have much length to it.
Could I just silicone around the leak point to bodge for now?

Pipe runs under the deck, never lifted it to see where it runs so now might be the time

[GliderRider]

If there is an O ring in the twist off cap, replacing it may cure the leak.