How To Install an In-Line Filter in 5/16" Steel Gas Line

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Gary Boutwell
10+ Years
10+ Years
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Joined: Wed Apr 23, 2008 10:10 am
Zip Code: 70401
Tractors Owned: 3 barns full of Cubs and implements in various stages of disrepair
Location: LA, Hammond

How To Install an In-Line Filter in 5/16" Steel Gas Line

Postby Gary Boutwell » Wed Jan 21, 2009 12:12 pm

There has been quite a bit of discussion on steel lines vs rubber lines. One problem
with the 5/16" steel line is that it doesn't provide easy installation of an inline filter which
will look original. (The originals did not have an in line filter. They used the antiquated wire mesh
filter in the sediment bowl. As we all know, they don't work too good!)

Following is one way to install an in line filter in the 5/16 steel line and retain
the original factor look.

Go to NAPA and buy one or more of the following filters

NAPA part number is 7-023357-1. It costs (locally) $4.00 including tax. Its cheap enough!

Cut the plastic housing away from the element. The small bronze element inside is all we want.

In order to make this work, one must grind off (or remove in some way) 1/2 of the shoulder material on the
element. I use a 8" bench mounted grinder, fine side, to do this.

One must also remove 1/2 of the original line between the ferrule and the carb.
I tried to line these up so you could see the difference in the elements and lines, before and after modification.
The brass line on top is for illustration purposes only. DO NOT USE BRASS LINES ON YOUR CUBS!
Most of the time, there is about 1/4" of line between the ferrule and the carb. We need only 1/8" for this project.
The other 1/8" will be taken up by the filter element.

After the line is cut or ground off to length, the inside will need to be cleaned out. I use a small countersink.

Now the line has 1/8" between the ferrule and the carb. The element shoulder has been ground to approximately 1/8" shoulder.

The element will slip into the end of the line and fit perfectly.
Put it in and install the line in the Carb. READY to GO!


What got me started on this project some years back, was in visiting my NAPA store while looking for a filter for a gas line, I saw this one. Got to thinking (which is unusual) that the shinted bronze element in this filter
was remarkably like the bronze filter in old Holley 4-barrel carbs.

Hope this works as good for you as it does in my Cubs.

BTW, this is # 501 post!
Last edited by Barnyard on Wed Jan 31, 2018 11:42 am, edited 1 time in total.
Reason: Added Missing Images
Louisiana Cub Fest, March 5 & 6, 2010
Gary Boutwell
Hammond, LA

3 barns full of Cubs of various condition

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