Gas Line Compression Fittings

by Scott Suhring

A common problem when replacing fuel lines on TR3s and 4s is that you cannot get a good seal since the original compression fittings are no longer available. The original brass gas line compression fitting was longer than today’s replacements. Look closely at your original brass ferrule and compare the extra wide flat area in the center and the total overall length against the replacement fitting. This is what is needed to keep the brass nut from hitting bottom before making a gasoline tight crimp on the fuel line.

To correct this problem, take two new compression fittings and grind away part of one end on each of the fittings. Put the ground ends together on the gas line to make the overall length about the same as the original. When you tighten the brass nut, both ferrules will squeeze onto the gas line and will not leak.

An easy way to grind away one end of each compression fitting to assure that the ends remain level is by taking a medium to fine cut file, laying the file on the work bench or table and then placing the end of the fitting on the file and running it back and forth until the desired length is left in that side. Do the same to the second compression fitting so that the remaining length on the filed side is the same as the first fitting. This will give the two new filed ends a level connection.

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