Radiator fan switch sensor question.

[harkgold]

While I had the radiator off the bike for repairs I decided to check the health of the radiator fan switch sending unit.
I removed the fan switch sensor from the thermostat housing and cleaned the layers of scaly crud off the brass end of the fan switch sensor. I then put some blue Lock-Tite and a new lightly greased "O" ring on the sensor and threaded it back into the thermostat housing and wrenched it down nice and tight and installed the thermostat and housing back on the engine.

I just happened to read (after the fact) in my shop manual where it says to also apply thread sealant or plumbers tape to the threads on the fan switch sensor before installation. I'm wondering.....won't the new rubber seal and blue Locktite that I put on this part suffice in keeping this part from leaking coolant? When I removed this part I didn't recall seeing remnants of any plumbers tape or thread sealant on the part so it didn't occur to me that anything other than the rubber "O" ring would be required. It came out of the housing with threads that were clean as a whistle.

Is tape or sealant over kill? When I replaced the rubber "O" rings on all the cooling tubes that run across the top of the engine under the carbs the manual did not suggest any additional goop to be sure these were sealed to prevent leaks.

Anybody had any experience with this? I hate to disassemble the front of the bike again if this is not really needed.

Thanks,

Harkgold

[bustedwing]

The blue loc-tite will take the place of the plumbers tape, don't take it back apart. But the next time you will prob. need to use a little heat to break that loc-tite.

[harkgold]

The blue loc-tite will take the place of the plumbers tape, don't take it back apart. But the next time you will prob. need to use a little heat to break that loc-tite.

Thanks Bustedwing! I thought maybe the Loc-tite would probably be sufficient; along with the new rubber 'O' ring. I couldn't imagine how anything would get by both of those.
Harkgold

[SteveB123]

Thread sealant is used on fittings that actually seal in the threads, i.e. tapered pipe threads. If this fitting has a O-ring, it'll have straight threads, and seal on the end with the O-ring.
It can't seal on both, as since the taper length varies, so does the "tighten" point on the pipe thread. An O-ring seal needs to hit the end of the fitting everytime, and compress that O-ring.

Cheers

[harkgold]

Thread sealant is used on fittings that actually seal in the threads, i.e. tapered pipe threads. If this fitting has a O-ring, it'll have straight threads, and seal on the end with the O-ring.
It can't seal on both, as since the taper length varies, so does the "tighten" point on the pipe thread. An O-ring seal needs to hit the end of the fitting everytime, and compress that O-ring.

Cheers

Thanks SteveB123!
Yup! since mine does have a rubber 'O' ring and I did replace it with a new one...I'm good to go.
I'm sure glad I check first with you guys before just tearing into things. It saves me a lot of unnecessary work.
Again.....another case where the shop manual did not explain clearly.
I swear.....I think I could write better shop manual instructions than what is being printed these days.
Harkgold

[Bamaeagle]

Thanks SteveB123!
Yup! since mine does have a rubber 'O' ring and I did replace it with a new one...I'm good to go.
I'm sure glad I check first with you guys before just tearing into things. It saves me a lot of unnecessary work.
Again.....another case where the shop manual did not explain clearly.
I swear.....I think I could write better shop manual instructions than what is being printed these days.
Harkgold [/quote]

Yep manuals are a good thing to have but they do have mistakes in them and also sometimes leave out a few steps.
I always check the manual and when I have a doubt or question I come to the forum for the answers cause it is a sure bet someone out there has "been there / done that".

[Growler]

Excellent post! I was just reading up on the subject since my 82 GL1100 is having a problem requiring me to change out the same switch, what's a good way to do this without (if possible) tearing into the bike too much? I can't quite get my hand in their to pull off the rubber boot with the wiring harness on it, but I might get someone with smaller hands to do it for me. What then, a 19mm socket? Will I spill a bunch of coolant (which I just replaced)? I guess I'm looking for some RnR instructions if anybody has some, thanks!

Bret