best sealant for petcock sealant

[goggles]

I replaced the vacuum petcock on my bike using an adapter plate and aftermarket petcock. Everything seemed to be well sealed but now a year later I have a leak.

After taking the tank off; cleaning the area; and observing the area. it appeared the leak was from the petcock threads. Upon a second look, there was a drop of gas hanging off the corner of the adapter plate. I wiped the side of the plate off and noticed a second layer the gas was running down along the whole edge.

I used hylomar sealant between the adapter plate gasket and adapter plate.

I used PTFE tape for the threads of the petcock.

So is hylomar a good choice or would something like Permatex® Form-A-Gasket® No. 2 Sealant work better?

Or maybe something else has worked for someone?

[Mikeyc]

I just purchased the proper OEM gasket/washer for the petcock bolts from BikeBandit. They were only a couple of bucks. That should stop the leak.

[twr1776]

The Hylomar is much better than the #2 Permatex. I would also use it on the threads. The teflon tape although good for natural gas and water might not hold up too well to constant exposure to gasoline. I spoke with the tech support person at Permatex before I got the Hylomar and they had improved the Hylomar formula recently and it is even better than the previous versions. They also mentioned the Motoseal as impervoious to fuel but I already had the Hylomar so that is what I used. So far I have had it on the tank for a week and no drips.

http://www.thegsresources.com/_forum/showthread.php?t=157694

http://www.permatex.com/products/Automotive/automotive_gasketing/specialty_gasket_maker/MotoSeal_1_Ultimate_Gasket_Maker_Grey.htm

[chef1366]

The Hylomar is much better than the #2 Permatex. I would also use it on the threads. The teflon tape although good for natural gas and water might not hold up too well to constant exposure to gasoline. I spoke with the tech support person at Permatex before I got the Hylomar and they had improved the Hylomar formula recently and it is even better than the previous versions. They also mentioned the Motoseal as impervoious to fuel but I already had the Hylomar so that is what I used. So far I have had it on the tank for a week and no drips.

http://www.thegsresources.com/_forum/showthread.php?t=157694

http://www.permatex.com/products/Aut...Maker_Grey.htm

Hylomar hands down.

[goggles]

Thanks and update

Thanks for the replies.

I removed everything for a closer look.

I think it was a combination of leaks. I believe the tape around the petcock threads had finally given up due to exposure to gas. It had a yellow tinge to it.

The adapter plate bolts were loose. I thought the petcock had just enough clearance from the top of the carb but there are rub marks on both so I assume the vibration helped loosen the bolts.

I have the hylomar on hand and will put it all back together with that. I assume I can reuse the adapter plate gasket as it seems to be intact?!

[Nessism]

Sealers have no business anywhere near fuel leaks. Find out what seal is leaking and fix it properly (replace the gasket/O-ring as needed).

[TheCafeKid]

Sealers have no business anywhere near fuel leaks. Find out what seal is leaking and fix it properly (replace the gasket/O-ring as needed).

Agreed! I think BWringer said it best with something like "I dont mess around when it comes to highly flammable substances that are leaking over a hot motor, 6 inches away from very important reproductive parts"...or something like that. Definately took that advice to heart

[Dave8338]

Sealers have no business anywhere near fuel leaks. Find out what seal is leaking and fix it properly (replace the gasket/O-ring as needed).

Hard to argue, Ed. Gaskets and O-rings as mentioned.

[gs road racer]

Couple of things.....I agree sealants have no place anywhere on a bike(ya I added that).... except between the crankcases which is it's intended use. That type of use I prefer three bond all the dealers sell it. Hylomar works well too.

Teflon tape and other goop for threads.. their primary function is as lubrication to allow the taper in the threads to seat this is the actual seal. we all use it in one form or another to help seal and to an extent it helps.

Gaskets are fluid.. I know it's hard to think of that but as you tighten surfaces together they flow and fill minute voids...the only thing that should be on them is a little grease(again the lubricant) to help them flow.Makes reusing a possibility too, but heat and age get em in the end.DO NOT grease head gaskets.

O rings are designed to seal with the pressure that comes from them being bigger(diameter) then the depth of what they sit in.Lubrication can be added to facilitate assembly as well and helps them not stick so badly when they come apart .

Seals since we are on the subject of sealing things....got a seal you need to last a little longer?Remove the spring that tensions the sealing lip (if it has one).That spring actually screws together so twist it a bit to shorten (reducing it's diameter ) not to much especially with rotating shafts. Might help get you by till a replacment is found. When you assemble seals use a little moly grease or some similar (think DRY condom? don't use KY....I'm sure that gets your attention)

IF something leaks it's because there's a problem FIX the problem. Warped surfaces, cracks old hard gaskets flattened o-rings simple simple fixes eh?Anything else is a bandaid to get you home or to the proper parts.It's as I said in the seafoam thread, miracles don't come in cans, jars or bottles...STP is a company built on the premise that it does...all snake oil...or is that snake doctors?

[bonanzadave]

In my world (Airplanes).......

http://www.aircraftspruce.com/catalog/cspages/ezturnlube.php

http://www.aircraftspruce.com/catalog/appages/ps890.php

[gs road racer]

In my world (Airplanes).......

http://www.aircraftspruce.com/catalog/cspages/ezturnlube.php

http://www.aircraftspruce.com/catalog/appages/ps890.php

Very interesting products!! But as with most things aircraft price!!!