Final word on case half sealers?

[cstreit]

1. My mechanic recommends "anerobic sealer"
2. Waynes book recommends Locktite 574
3. "dow 700 series sealant is the sealant of choice"

So what is the deal, I don't want to do it twice?!

Oh, How does one remove the old stuff off the case safely?

AND...

DO you squirt a bead on, or is it better to have the sealer across the whole sealing surface like applied by a small paint roller?

[Doug Zielke]

Chris, I doubt there could ever be a *final* word on which sealer is best (just like brands of pistons, LOL).......but John Walker recommends and uses Dirko. I don't know where he buys it, but he was nice enough to give me a tube. Superman also used Dirko and has reported a leak-free installation.

I gather the big advantage of Dirko is that it is not as time-dependant after you spread it on the parts.

Just *how* you apply it is a question I forgot to ask John. Hopefully he will reply here.

[silverc4s]

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Originally posted by 1974carrera
Pretty cool of you to post the pics, Chuck...always like looking at engine stuff. I've used Yamabond 4 for quite a few years and think it's great for surfaces like the timing chain cases, etc., but have never used the Yamabond 5. Guess I need to check it out. Is it designed specifically for engine case sealing?
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I'm not sure, it is what my builder uses, I just pay the bills

Search "case sealant" on the 911 Rennlist archives (or this BBS) and I'm sure you'll find a variety of opinions.

Also, I didn't use the expensive studs. Just replaced the bottom row. The first set was good for 100K+ miles, so I'm not sure the added expense is worth it. I mean I only drive 200 miles a weekend at the most.


Soooooo... I guess you can add Yamabond 5 to the list. Is that from Yamaha??? They've certainly sealed a LOT of alloy cases in THEIR time, eh?...

[cstreit]

... what do I use to clean off the old case sealer? Razor blade and care or some solvent?

[silverc4s]

You can use a blade. Be V E R Y careful not to gouge any metal off of the mating surfaces...

[slakjaw]

anyone ever had any luck with the Permatex aircraft form a gasket. stuff


LATE
K

[silverc4s]

Don't use the Permatex to seal case halves, it is not a strong enough sealant. There are only a very few very specialized sealers that will not leak in this application, especially with the mag cases, I believe...

[zuffenhausen]

The Loctite 574 is what the factory uses, and it is an anaerobic sealant, so that agrees with both Wayne and your mechanic. You should spread it across the sealing surface. You can use a small roller for that if you want but I just carefully use my finger. Keep in mind that you have limited working time with the 574 so have everything ready to go together before you apply it.

-zuff

[cstreit]

Do you apply it to both halves? Just a skim coat? (IN other words, super thin, or a nice 1mm layer?

Should I just use carb cleaner on the sealing surfaces to preparte them for good adhesion?

Presumably you use the same thing on the head to cam-tower seal?

[john walker's workshop]

do a search for loctite 574, or 574. on occasion, it sets up before being squeezed out when the cases are torqued. then you have problems. no, it can't be 1mm thick for the above reason. yes, a tiny little roller is recommended.