39 replies to this topic

[RooBoonix]

theres an old chap on YouTube who has his own classic Mercedes workshop and he certainly knows his stuff and he uses aiviation permatex


Possibly poor quality half moon seals in circulation?

 

Aviation Permatex is excellent stuff, I like the smell of it too    I'll be following this thread closely, as I am currently rebuilding my engine and am unsure whether to fit a solid or flexible half moon seal...

[KernowCooper]

I would not use Hylomar on the half moon its for compression joints on gaskets not seals, use RTV

Edited by KernowCooper, 09 January 2017 - 09:42 AM.

[panky]

Advise will be heeded, thank you.

[Spider]

theres an old chap on YouTube who has his own classic Mercedes workshop and he certainly knows his stuff and he uses aiviation permatex
 

 

Well, there you go, that's actually the stuff I use. Loctite bought out Permatex a few years back It was Permatex 3J back when I first started using it.

[tiger99]

I have never heard of Permatex. Possibly that is because it is not easy to find. Maybe I should give it a try some time.

I think that almost any non-hardening sealant should work (no Green Hermetite and such like, hard sealants will impair the rubber to metal seal), and the overlap between half moon and side gaskets is in straight compression so even Hylomar ought to work there, but not on the curve, where nothing should be needed but, if you must, a flexible sealant should not cause leakage if you can overcome the assembly problems it may cause.

[ACDodd]

Too long, I have been cutting them too recently.

Ac

[panky]

I'll certainly check the fit before bolting everything up,

[gav]

The old rigid type weren't available for years until we had them remade recently.

[whistler]

I have never heard of Permatex. Possibly that is because it is not easy to find. Maybe I should give it a try some time.

I think that almost any non-hardening sealant should work (no Green Hermetite and such like, hard sealants will impair the rubber to metal seal), and the overlap between half moon and side gaskets is in straight compression so even Hylomar ought to work there, but not on the curve, where nothing should be needed but, if you must, a flexible sealant should not cause leakage if you can overcome the assembly problems it may cause.

Red Hermatite was used before Hylomar was popular; not as good though, you had to scrape the gaskets of with Red.

[podifold]

I did a comparison a while back between the flexible aftermarket seal and a NOS rigid one:

 

http://www.theminifo...oon-seal/page-2

[cian]

You did well getting hold of a genuine one!

[panky]

It does look a bit long. 

I was thinking to trim about half of the extra off to give it a bit of 'squish'. Any thoughts?

 

Edited by panky, 09 January 2017 - 04:38 PM.

[tiger99]

Hard to know what is best because it has a different structure to the old one and will compress differently. I think that the new one will compress more due to the thin rubber ribs. If that is correct it must not be trimmed. But it must start properly centralised. I expect you know that and just posed it roughly for the photo.

I fear that there will be difficulties at the ends, where the sump gaskets overlap, as the new seal is not as solid as the old one. You will need more sealant, of the chosen flexible type, at these places than previously. I suspect that it is those interfaces between gaskets and half moon that are leaking in many cases.

My overall impression is that this is yet another amateurish designed product, from the usual source of such things, and the original design will be far better.

[whistler]

Dare I say it but I'm more than happy with how I fitted the seal and also if I remember right I put a dab of silicon on each end but from what I can see it's started leaking at what I'll say is about 8 O'clock when looking straight at it. 

I too am surprised that I could replace it with gearbox in situ and it might work and if based on what is advertised might even fix it but I'm only doing so because I don't yet want to pull it all apart just for one leak so am willing to try for what is a days work.

 

But if anyone has done so with success please let us know about it.

 

And when I do it I'll take pictures but might be a couple of weeks off yet. 

Did you manage to fit the CAM6548 in situ? 

[MiniGilly]

I'm back! Stuff has meant I am only now back onto fitting the rigid seal. All is stripped back, timing chain/gears, back plate etc. And I'm checking the location for the seal. Which is longer than the soft one and appears to fill the space better. I'm going to need a drop of rtv on the ends and just for luck a thin layer on the seating face considering it's held in place by the backplate but I do think I'll be fighting to force it into position. I'll take some pics but can post up just now.
Shall be back as soon as I can
Cheers