2bbl Carb Leak

[LarryC]

I have a 74 C10, 350 2bbl. Stock.

I had a fuel contamination problem (rusty particles getting into the fuel filter, and into the carb. This truck had been driven summers and stored winters. Fuel tank was replaced about 10 years ago, has an in-line filter right as the line comes out of the tank and nothing in that. I replaced ALL lines and fuel pump forward of the tank (you could see rusty spots in the metal lines). Disassembled and rebuilt and cleaned the carb.

The truck runs great (starting warm and cold, idling, driving, accelerating, everything). Only problem I have left is that about 30-60 minutes after shutting it off, it leaks some gas out of the carb and into the recesses in the intake manifold beside it. There is also the moderate smell of gas in the garage. I set the float height and drop per the specs with the little gauge that came with the re-build kit.

Any ideas? Thanks, Larry

[roundedline]

Has the carb been rebuilt?  Can you tell where the fuel is coming from?

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[LarryC]

Yes, I rebuilt it with a gasket set, so it has new gaskets, new float, needle/seat, filter, and power valve.

I can't see any particular place it is coming out so I am guessing it is coming out the throttle shaft ends. Can't see anything on the body of the carb.

[DnStClr]

Do you have a steel fuel line between the pump and carb? I have read that when an engine gets up to operating temperature, the fuel in that line can actually boil if it's too close to the exhaust manifold. The heat is transferred from the hot manifold to the steel line. After the engine is shut down, the boiling fuel in the line overflows into the carburetor and leaks as you've described.
The fix is to use a rubber fuel hose (make SURE it's a fuel hose) between the pump and carburetor, and fuel hose clamps too. Being very cautious where you run the fuel line!

[LarryC]

In replacing the pump-to-carb line (along with all the other lines) I could not find a steel replacement that fit it exactly. The old on had LOTS of bends, and hugged the front of the block very closely. So I used the steel fittings and about 2" of steel line on each end and connected them to a piece of 3/8 fuel line with double clampos on each end, so it already has rubber hose on it. Good thought, though. Thanks.