Re: 73 Jav vac cannister

["Joe Wyatt" <jwyatt@xxxxxxxxxxxxxx>]

Todd, if it on the pass side it's the charcoal canister for the fuel system, 
you need to leave it (or replace it if the charcoal filter is not intact). 
The purpose is to vent the fuel tank, the gas fumes gets trapped in the 
charcoal (also helps keep moisture "WATER" out of the gas tank) when the 
engine is off and the tank breathes.  Once you start the car, the vacuum 
from the engine pulls a small amount of air back through the filter to 
remove the gas vapors from the charcoal and burn them in the cylinders.

If it's on the driver side or back wall it's the Vacuum canister, you need 
it at LOW RPM so the engine will idle right.  If you add a performance cam 
you may need a larger one so the Vacuum assist systems function during low 
RPMs.


Date: Thu, 07 Apr 2005 07:44:38 -0400
From: farna@xxxxxxx
Subject: Re: 73 Jav vac cannister
To: mail@xxxxxxxxxxxx
Message-ID: <ADVANCES62RGryWtIIZ00000031@xxxxxxxxxxxxxxxxxxxxxxx>

Vacuum canister or charcoal filtering canister? If it's indeed a vac anister 
leave it. It's a storage device. Should have two fittings, basically an 
input and output. These should be one-way valves (at least the input should 
be). Simple test -- you should be able to suck air out of it but not blow 
in. Both may have one-way valves, or the valves may be an insert in the 
hoses. If you can blow and suck on a short hose connected to the input and 
output disconnect the hose at the other end and check it. If no one way 
valves the canister will not store vacuum properly and will leak down.

To see if it's a charcoal canister check the bottom. Should be cut out, not 
solid, with a filter over the openings. There will also be three vacuum 
lines attached, not two. You can still buy filters for the bottom of the 
canister. I don't know how they come apart, a TSM should instruct on 
servicing. There are probably one-way valves on this too, but I don't know 
which lines would have them.

On April 6, 2005 Todd Wallis wrote:

> I'm cleaning up the engine compartment on my 73 Javelin while the engine 
> is
> out.  What is the conventional wisdom about leaving out the vacuum 
> canister
> on the on the left shock tower.  After all these years is it still even
> working properly?  Thanks for any input.
>
> Todd Wallis