Keep the hard plastic tubing as it lasts forever and don't bother with the cloth covered stuff. I believe 7/64 standard vacuum tubing is the correct size. For the tee between the warm up (auxiliary) air regulator and manifold the small connection had a restrictor in it. I don't remember the size but it is important as it meters air from the tank vapor recovery system. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of John Lauterbach
Sent: Monday, May 30, 2011 4:36 PM
To: vanagon@GERRY.VANAGON.COM
Subject: sources for small vacuum tubing and fittings

Following-up on suggestion that I had a vacuum leak, I found several suspect pieces of tubing and connectors.  My engine has combination of rubber/cloth vacuum tubing and hard plastic vacuum tubing.  Can I go with the rubber/cloth vacuum tubing -- looks like 3 mm ID.

Another suspect point was a fitting that connect a small diameter hard plastic tube with the tube coming from the axillary air regulator and the outlet end of the connector goes to the intake manifold.  Where can I get the connector?  I had dummied up a connector many years ago and I think it has sprung a leak

Engine in 1.9L in 1984 Vanagon

Thank you,

John