Easy fuel breather mod
Posted: Fri Aug 03, 2018 6:10 pm
I?ve been thinking modifying the filler neck for the breather mod for a while but not seen a solution that meets my needs. I don?t want to weld a boss on the filler neck as I?ve plated it already, want it suitable to fit after the filler neck is installed and I don?t have access to a lathe. I?ve come up with a simple solution that may be useful to others.
* Starting point is a 8mm straight domestic plumbing brass coupling, but a 12mm or 15mm could be used.
* Cut the olive retainer off one of the unions, effectively turning the union into a brass nut.
* File the non-olive end of the 'nut' to suit the curve of the inner surface of the filler neck. Mark two opposite faces so you know which you?re filling, holding the nut and neck to the light to assess the fit. With care you can get an tight fit.
* Round off the ?cut? end of the nut.
* Drill the neck to an appropriate size so the coupling body is a snug fit. Too big and it will be difficult to seal. Make sure the hole is only finger depth down the neck as you need finger access to assemble it.
* Fit the coupling body through the hole, slide the nut down the neck and tighten the coupling pulling the nut tight against the neck inner surface, making sure the nut is correctly aligned.
* For final assembly apply a suitable sealant or PTFE tape to get a fuel tight seal.
* Make an appropriate tail for the non-modified Union end and connect to breather pipe work.
Hopefully the following photo?s explain. I?ve used 8mm but maybe 12mm would be better. I?ll see and modify accordingly.
* Starting point is a 8mm straight domestic plumbing brass coupling, but a 12mm or 15mm could be used.
* Cut the olive retainer off one of the unions, effectively turning the union into a brass nut.
* File the non-olive end of the 'nut' to suit the curve of the inner surface of the filler neck. Mark two opposite faces so you know which you?re filling, holding the nut and neck to the light to assess the fit. With care you can get an tight fit.
* Round off the ?cut? end of the nut.
* Drill the neck to an appropriate size so the coupling body is a snug fit. Too big and it will be difficult to seal. Make sure the hole is only finger depth down the neck as you need finger access to assemble it.
* Fit the coupling body through the hole, slide the nut down the neck and tighten the coupling pulling the nut tight against the neck inner surface, making sure the nut is correctly aligned.
* For final assembly apply a suitable sealant or PTFE tape to get a fuel tight seal.
* Make an appropriate tail for the non-modified Union end and connect to breather pipe work.
Hopefully the following photo?s explain. I?ve used 8mm but maybe 12mm would be better. I?ll see and modify accordingly.