Thread sealant
 

I've been having issues lately with the connection where the fan sensor attaches to the radiator on my SV. I loosened it a few weeks ago and it was majorly cross-threaded; as a result of taking it off it wouldn't re-tighten properly and would leak pretty badly once the bike was started.

I have since had the thread in my radiator helicoiled with a steel thread but although the bolt now tightens pretty well, there is still a very small bit of leakage coming from the connection. I think the helicoiled thread is (very slightly) too large for the bolt.

Tomorrow I am going to try adding some PTFE tape but I was wondering if a smear of 'Instant Gasket' or some other sealant compound would be good for sealing the connection better?

Or has anyone got any other recommendations? Any help appreciated!

Re: Thread sealant
 

There must be someone else who has had a leaky connection somewhere?? :)

Re: Thread sealant
 

The tape will do the job,but don't slap a lot of turns on it,normally a couple of turns will do.

Excuse me asking but are you 100% sure it is the thread that is leaking as helicoil is normally pretty good fit providing the correct size is used.Perhaps the sensor threads are damaged which the tape should rectify

Re: Thread sealant
 

I agree.

Re: Thread sealant
 

Well I've just taken the fan sensor out again and smeared some Heldite on to the threads and also replaced the rubber o-ring with a new one as the old one looked a little worn. I will let the Heldite cure for 24 hours and see if it's OK tomorrow.

Re: Thread sealant
 

If this doesn't work, then and old trick we used to use was some fibres from a rope. But it has to be a natural rope made of sizal. When it gets wet i expands, making the seal tighter.

I think you can get plummers twine or something like that, which does this from somewhere like screwfix

Re: Thread sealant
 

Thanks Maviczap, will try this if this doesn't do the trick. I have bought some plumber's tape just incase!

Re: Thread sealant
 

Well I've just come back from a decent ride on the bike and it's now sorted. Did around 75 miles and no sign of the leak. Heldite and the new rubber washer did the trick! :)

Re: Thread sealant
 

Good morning.


Glad to hear you got your problem sorted.

Often with Helicoils, or similar thread restoring inserts, the installer doesn't get the thread for the insert quite square, leading to the item ending up slightly skew wiff!
It's good practise to use PTFE tape, or a non hardening compound on such items as a precaution.


Cheers.