thread sealant on turbo oil drain pipe

[Anthony P]

What is the preferred sealant for the threads on the brass adapter that threads into the block and for the threads on the flex drain pipe that connects to the brass adapter?

Should white teflon tape, yellow teflon tape, or some other thread sealant be used. Thanks.

 

[imjoesnuffy]

I recently replaced my leaking turbo oil drain line with a SS braided tube. Bypassed the brass adaptor and just used the white liquid thread sealant. No leaks yet.

 

[Anthony P]

Since I left most of that stuff on a side job that I won't be back to until later today, I'm trying to see if I have something else on the shelf that will work. So far I only found grey pipe dope and orange pipe dope (for nat. gas) and I don't want to use those products.

I was going to use the HVAC blue joint compound since it is resistant to loosening by thermal expansion and it's made for sealing oily fittings - but that stuff is at work.

I just wasn't sure about the white thread sealer liquid paste (liquid PTFE) when used where contact with oil can occur. Is this correct?

 

[Anthony P]

I think I answered my own question... the white liquid thread sealant with teflon is resistant to common shop fluids. At least that's what the Loctite brand container says now that I found it.

I'll have to check the temp spec. on the regular white paste sealant. Maybe better to use a 567 PST sealant. That stuff has a temp rating to 400F same as the HVAC blue sealant.

Please let me know if you guys have different opinions. Thanks.

 

[Anthony P]

Since there are no other threads on this topic, I'll post a follow up....

The end of the flexible oil drain tube is a flared fitting so no sealant should be used on these threads. Just a little light machine oil to lubricate the threads as the connection to the brass adapter is tightened.

For the brass adapter to the block...

white teflon tape will dissolve over time when exposed to oil.

the HVAC blue thread sealant I spoke about earlier cures hard so not a great choice. It's fine on black iron pipe but not so great a choice in this application.

It seems that the best choices are:
Permatex® High Performance Thread Sealant
Permatex® RTV Silicone Adhesive Sealant - Clear or Black OR an AST-RTV silicone sealant
Loctite 542, 565 PST, 567 PST...just to list a few.

 

[Lee Thompson]

block thread

That is a NPT thread --tapered--so actually you COULD get by without any sealant. The white teflon will work just fine. Contrary to belief that is not a sealant it is a lubericant. So anything to lube the tapered threads so they will go up tight will work. The oil in that area is NOT under pressure. Best of luck.

 

[RmvBfrFlght]

My vote is for the PST 565 on pipe threads. In engines I avoid RTV and teflon tapes like they carry the plague.

RemoveBeforeFlight

 

[imjoesnuffy]

I just went out to the garage to check. The stuff I used comes in a small white tube. Permatex High Temperature Thread Sealant.