[TR] SU Leaks

[Alex]

Thought I would share this finding concerning my leaking SU's on my 59 TR3A. I
have been living with an intermittent leak from the bottom bolt that attaches
the float bowl to the carb body on both carbs. Tightening, loosening,
tightening would ultimately seal the gas leak. At times it would stream
regardless of how tight it was made. But recently I could not get it to stop.
Leaking at the bottom just above the exhaust manifold did not make me too
comfortable. Spoke with Joe Curto who recommended his Viton seals. I ordered
them and received them in 3 days. They hold up to modern fuel blends much
better than the standard rubber ones and we thought the seals in my rebuild
kit were deteriorating. Two required/bowl, top and bottom. (note-Joe's seals
are better designed as they have a groove on the contact side that better
grips the body) After installing them, I still had a strong leak from the
bottom bolt on the front carb. Long story short - after examining the bolt, I
discovered that the hole in the bolt that allows fuel to pass was actually
just below the top of the seal where it grips the bolt body. This allowed the
fuel to pass between the seal and the body of the bolt and out the bottom
bypassing the effect of the seal. By pressing the base of the seal all the way
down against the washer on the bolt head insuring that the top of the seal was
below the bolt hole and then carefully installing the bowl immediately solved
the problem. The hole in the bolt is slightly elongated top and bottom. This
elongation just about touches the top of the seal that grips the bolt body. If
the seal is allowed to be above this elongation the bolt will leak regardless
of the seal. I felt like I was on the show Mystery ER. Don't know if anyone
else has experienced this leaking problem, but if so you might want to check
this out.
Alex Manzo
59 TR3A