pushrod tube seals with teflon thread sealant, how do you apply it? Options

[mightyohm]

I have read on ST Forums that Jake uses Permatex teflon pipe thread sealant to seal up pushrod tube seals. Does anyone (Jake?) know how to properly apply this stuff? Do you put it under the seal (in the "channel" of the pushrod tube) as well as on the part of the seal that rides in the case? Should I glop it on or just use a little bit?

Also, if I have green rubber seals for the head end of the pushrod tube, do I have the correct ones? I thought the Viton ones were brown? I am assuming that because the head gets hotter, that side matters the most.

[MattR]

Ive read in multiple places the pushrod tubes were supposed to be sealed with the O Rings moistened with motor oil. I am going to start my rebuild in the next couple of weeks, so I guess Im kinda confused.

[TheCabinetmaker]

I've used wheel bearing grease on my last three engines. No leaks yet. Just a very light coat on the o ring itself. I use it on the valve covers too. A generous coat there. Makes it easy to remove the valve gasket on the next adjustment too. Teflon pipe joint compound should work awesome.

[Ray Warren]

I did mine and used green O rings and Quaker State
100% synthetic grease and they are as dry as can be. I put a good coating all over the O rings, tubes, holes in head and block. And of course make sure every thing is clean. Also make sure that the tubes move freely back and forth after you have
re-installed them.

[mightyohm]

Wow, so noone other than Jake is using the PTFE paste??

I have heard to use motor oil and synthetic grease also. What type of synthetic grease would I look for? Is normal white lithium grease not good enough?

[Jake Raby]

Engine oil is what is supposed to work.. It don't, atleast not for a bone dry engine.

We use teflon and never have leaks. I use a tad bit in the channel and on the outside of the seal...

This is one of the 13 sealants it takes to build a leak free engine, that stays that way.

I have tried everything on PR tubes and Teflon has been the best no doubt!

[mightyohm]

Thanks Jake. I found some TFE thread sealant paste at the local hardware store that I believe is the same as Permatex. It's a goo with a consistency a little thicker than antisieze. It's rated to 500F. I am going to try it and see what happens.

[dmenche914]

Also very important in o-ring sealing is cleanliness, and making sure all the push rod tubes are round, and all surfaces are scratch free. Also lube the oring, so it slides in easy. I have found the o-ring tends to cock and twist, even with lube, so a little nudging with a wood stick (or other blunt soft object) can help keep the o-ring going in correctly. Twisted o-rings will leak.

dave

[adam912]

More stuff to check: The assembly I did a year back, the engine leaked like a sieve. I decided to take a close look at the pushrod tube situation while I had the heads off a year later, so I assembled O-rings to a couple of tubes and tried the appropriate end in the appropriate hole. While all of the head-end fit-ups were nice and snug, most of the case-ends were loose as a goose. It appeared that 6 of the 8 O-rings had shrunk badly. All of them had come from German rebuild kits by the way. I grabbed a handful of new O-rings, tried them and found a snug fit to be restored all locations. I used Jake's Permatex Teflon on all the O-rings (smeared sparingly on the outside diameter of each O-ring) and the engine has been dry as a bone for 5 months. My STRONG recommendation is: check the fit of tubes in holes while you have the heads off. There is enough O-ring friction when you do this with a assembled long block (heads on) that it would be very hard to tell if one end or other was loose in the bore. Check one end at a time!

Adam912 Out
'66 912, 2.2L T4

[mightyohm]

I have read that the black o rings that come in the gasket kits (I have a set) are not very good. I have been tempted to take the heads off this engine to see what the situation is inside, but I think I will leave them on for fear of breaking any exhaust studs or other parts. I have about a week to get this engine ready to go back into the car.

[Jake Raby]

With my Teflon trick you can reuse old seals and junky black ones and they still seal off!

[Dominic]

QUOTE: I thought the Viton ones were brown?

ANSWER: It depends where you get them. VITON O-ring Seals come in many colors, I have ordered them in bulk for both ends of the pushrod tubes and they are all Black in color.

I have never had a problem with the Viton Seals leaking when installed Properly.

[ThinAir]

After researching sealants here and STF I'd come to the same conclusion - that Teflon thread sealant was a good thing to use in this location - and that is what I was planning to do on my engine. Unfortunately, the last time we had a thread like this I could never get such a straight answer so I'm really delighted to see this confirmation. Can you post a link to the STF thread where you found the original info on this? I haven't been able to keep up with both STF and 914Club.

[Jake Raby]

Guys... We do about 60 full engine builds a year here..everyone of them gets dynoed.

Out of all those we may have two oil leaks at the tubes all year- They stay that way when they hit the car

Don't worry about theories, don't worry about the way the factory designed it... just use the Permatex part# 56521 on the seals and don't worry about leaks...

It took me 5 years to build a bone dry engine- you won't do it on the first try in most instances- if you can do it, I'll give ya a job!

[swood]

Teflon on both ends of the pushrod tube?

[michelko]

I am looking for this product in germany. I could not find it (IMG:style_emoticons/default/sad.gif)
Is there an comparable product from an other Manufacturer?
Loctite for example

Thanks (IMG:style_emoticons/default/smilie_flagge6.gif)

[Steve73]

I have my engine out and am going to replace the seals. Should I replace the tubes as well?

Any product updates since this was first posted, I'm sure there are new options.


"... just use the Permatex part# 56521 on the seals and don't worry about leaks..."

[r_towle]

I think we should wait for Elliott to weigh in on this, with pictures, and make sure SLITS, his advisor can properly describe the technique

[Steve73]

(IMG:style_emoticons/default/popcorn[1].gif)

[stugray]

I used the teflon from Jake's engine sealant kit.

It works perfectly. I think it is permatex 56521 (Jake?)

If you are doing a complete rebuild I highly recommend Jake's kit.
Seems pricey at ~$100 (IIRC) but worth it.