You can usually feel a leak with hand or holding a loose piece of paper near it Block the outlet end with scrunched up damp cloth and you'll hear it too.

 

Always worth using some exhaust paste as the parts can expand and contract with heat. Probably not in this current weather though.

as weird as it sounds clear silicone seals exhausts a treat , i didnt believe it but it works...just regular stuff used for sinks etc

 

dont go stupid pulling the clamps up as it can dent the pipe then will never re seal again

I have nothing to actually check for leaks but i can't see any signs of leakage around the connection.

Only thing is literally a tiny section that looks like it could be a bit more snug. I measured both pipes and they were pretty close so i'm guessin they are seated quite nicely inside.

I saw a video of someone replacing a back box on something else and they popped what i thought may have been gun gum on the inner pipe. But i know that sets. Silicone does too but probly not as hard as gun gum. Thanks. I actually need to redo the taps in my bathroom so i'll pick some up and try that. 

I’ve used Silicone sealant on my exhaust and it works a treat. The Proper exhaust paste that sets harder is all well and good, until you want to separate the exhaust sections again.

 

Just the standard No Nonsense sealant from Screwfix at about £2.50 a tube, works just fine.

As dvderlm says, to check for leaks just have the engine idling and put a lump of damp cloth over the exhaust outlet, you’ll here the ‘chugging’ sound of a leak straightaway.

 

Edited 16 January, 20215 yr by mk2tastic

Awesome. Thank you dudes. Exactly the reason i was wary about putting gun gum on it. I'm fairly certain i'll end up taking it apart again at some point. Will check for leaks but will probly use some sealant regardless for my own peace of mind. 

Thanks again for your time and xp dudes. Very much appreciated. 

just remember silicone isnt suitable for use upstream of an o2 sensor or cat ...not that many mk2 owners have one , just saying ...after the sensors its fine

Neither present on this bad boy. Thank you for bringin it up though.