Which is the correct "Molykote" grease that the manual specifies when lubing o-rings?

I have this question too. I was going to go with the Molykote 33 but I don't know if I can find it here. The assembly is a plastic housing with two orings. Is there a non industrial product that I can use? I called part store and the gal said oh we have Moly! it's in a tube. But it's not the item I am showing here. Will that work

Thanks for any help.
Image Unavailable, Please Login

 

As in the other thread, others and my recommendation is silicone grease for all O-ring applications.

I would worry more about the rubber used for the O-rings. OEMs often are inferior. I since long use Viton O-rings only due to their superior chemical stability. They are obtainable in all needed dimensions.

Cheers, Bernhard

 

That is a good mention about the o-rings Bernhard. I do give them a check when I have access to them. Just to make the thread more useful for the next guy here are some things to consider. Deformation, cuts, nicks and abrasions are usually easy to spot. Carefully removing the o-ring with a dull pick and running it gently through the fingers can usually tell the condition of it. I like to clean out the o-ring groove too. It should be very clean so the o-ring can do it's job. Then lubricate the o-ring in your hands and re-assemble. A light coating of lube should help it on its way back home.

Now to find some lube!

Here is the bible for o-rings for anyone wishing to dig deeper into this incredible engineering solution.

https://www.parker.com/literature/ORD%205700%20Parker_O-Ring_Handbook.pdf

 

Sounds like Molykote 55 is what they want--at least that's what I remember anyway.

 

I am not so sure about the 55 stuff. If the o-ring groove is designed and machined correctly and the o-ring is sized correctly why would we need a swelling agent to make the seal work?

..."Molykote 55 is a strong, silicone-based substance that will swell natural rubber and other materials to make a more powerful seal."...

 

I think that's the issue, "If the o-ring groove is designed and machined correctly and the o-ring is sized correctly".

The O ring between the gear box and engine (360 - oil feed from tank to engine).
it just looks like it's too thin for the job to me.

Get the feeling that rather get the correct O-Ring made - they just went with off-the-shelf and some Moly-55.

 

Because it is the reinstallation process that is potentially damaging to the o-ring.

O-ring land and grooves for permanent assembly are different specs than for maintanenced assemblies.

 

The book doesn't specify which Molykote IIRC.

 

...just a rhetorical response...
I think this is good logic but am not sold. Are there permanent o-ring assemblies in cars? I will definitely report any oil drops around this area. After chewing on it for so long I think the best bet may be to just replace the o-rings periodically and use what you want (even motor oil). How many chemically induced swell cycles could they endure and still be healthy?

 

I thought so as well for a while until I stumbled across it. Much like their mentioning applying an applicable lubricant (in this case copper anti-seize) to the spark plug threads--which also took some hunting to find.

An alternative to moly 55 sounds like AGS Silglyde--at least from the two minutes I spent googling.

 

Just use a drop of oil and call it a day. Has worked for me for years and takes a lot less headache.