Date:         Sun, 13 Jun 1999 16:51:29 -0500
Reply-To:     Joshua Van Tol <jjvantol@USWEST.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Joshua Van Tol <jjvantol@USWEST.NET>
Subject:      Re: fuel lines; the injector side
In-Reply-To:  <199906132028.QAA28109@mail.enter.net>
Content-Type: text/plain; charset="us-ascii"

>Thanks to Coby for the write-up on the how-to of the injector fuel
>hose R&R and all the others who shared their collective wisdom.
>
>While some suggested reusing the ring clamp, it seems prudent to
>replace it with a proper fuel line clamp.

It seems prudent, but it isn't. The barb on the injector is specifically
designed to use the ring retainer system. If you look at it, you'll see
that it's not really a barb at all, but a special shape that causes the
hose to lock under the ring. Using a clamp will probably work ok, but
there's some danger of the clamped connection failing because it wasn't
designed to be used this way. Aero quip, earls and other high performance
hose and fitting manufacturers sell similar fittings, and they are VERY
reliable. High performance hose and fitting systems rarely use clamps, they
either use a special fitting that grabs the hose on the exterior and
interior, or they use the barb and retaing ring design.

I'd have to say, that, in general, it's prudent not to "improve" something
that that isn't broken, and in fact, was probably quite well engineered.
Keep in mind that the ring system doesn't suffer from several failure modes
common with hose clamps. These being: broken hose due to overtightening of
the clamp, broken clamp, possibly due to overtightening, clamp coming loose
due to vibration. I have never in many years of working on fuel injected
engines, seen the ring connection fail. I've seen hoses crack and split,
but they never came off the injector.


Joshua Van Tol -- jjvantol@uswest.net