Date:         11 Dec 96 14:56:39 PST
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         CARVER_JEFFREY@aphub.aerojetpd.com (Jeff Carver)
Subject:      Re: Vacuum Leak

Judy asks (type2 list) -
> I had to tap into the intake manifolds for vacuum for my brakes. Now the
> 2.0 won't pass emissions because of a vacuum leak. Does anybody know any
> tricks for sealing vacuum leaks at the fittings. I can't get teflon tape
> or pipe sealant to work. The tap seems too tight.

I did some experimentation when I put my FI stuff back together 
recently and have been hesitant to post to the list for fear of 
getting requests for the *stuff* I used.  I don't know where to get 
it yet.

I used a product that is specifically designed as a lubricant and 
sealant for vacuum systems.  I deal with vacuum furnaces at work, so 
am familiar with this stuff.  It's called vacuum grease.

It is a thick silicone goo that stays gooey, lubricates soft seals, 
and does not evaporate when a vacuum is applied.  This last factor is 
termed *low vapor pressure*.  It means that the product has to be in 
a very low vacuum (vapor pressure) to evaporate.  It stays in place 
and doesn't get sucked into the vacuum under the relatively soft 
vacuum generated in our VW's.

I treid some on a couple of rubber hose to metal fittings (on the air 
box) just for yucks.  The stuff works.  It holds vacuum really well, 
gets a tad harder that when applied, acutally becomes sticky with age.

I did some quick searching on the net for this stuff.  Very pricey 
stuff.  About $9 for 5 ounces of the Dow Corning product.  we use 
the Kinney stuff at work.

If this stuff can be found at a reasonable price, it would be another 
tool in our kit of tricks to stop vacuum leaks.

Maybe someone else can continue the search for this stuff.  I will 
try, but time is limited.

- Jeff
'80 Westi