The Stovebolt Site Forums The Shop Area Engine Shop Fuel smell

Two things. First after I've driven my restored 53 3100 and bed it down for the night, the next day fuel smell has entered the cab. Could it be comming from the vacumm operated wiper motor? If so how do I stop it? Second, I get a slight fuel smell while driving down the road with the airconditioning vent opened. The rear of the hood stayes up about 3/4 of an inch. I've looked for fuel leaks after driving the truck and see no gas leaking.

If the 53 still has the in-cab tank it could be the sending unit gasket has failed and is allowing a bit of fuel to leak. It only takes a few drops of gas to stink up a cab. My 38 had a slight leak at a fuel pump fitting that caused the whole garage to smell of gas & it was such a slight leak that nothing ever hit the floor. I just happened to see a drop while working on that side of the engine once.

Also, check the fuel filler rubber tube. I had one split from deterioration -- found it when gas spilled through when filling up with gas.

Just a suggestion....after you've checked for the obvious fuel leaks at the tank,sender, filler neck, fuel pump....look under the rear intake manifold port and see if there is a stain down the side of the block. Behind the accelerator linkage bellcrank. I had a similar problem with my Rochester dumping a little fuel after shutdown and it trickled to the rear of the intake....seeped past the intake gasket and down the side of the block. This was compounded because the PO hadn't installed the 3 little rings that align the intake with the block. There was no obvious vac leak but raw fuel was seeping past the saturated gasket. The smell naturally went away when you cranked the engine and drove it. Something to check! If you've got the stain it might take some tweaking of your float level to correct the problem.

You mentioned your hood stuck up..loosen all your hood bolts slightly...putting a 4" block under the front of the hood...right on top of the latch. With 2 "helpers" pushing down and back on the very rear of the hood, tighten down the inside bolts on each side. Raise the hood and snug the 2 bolts. Close it gently and check for interference. If your hinges aren't worn out, this should help close the 3/4 gap. Hope this helps.

Thanks guy's, I'll check that, but still looking for answers. The rubber hose is new. As for as hindges, I have no wear patterns or enlongated holes. My hindges are sitting on the curved cowel, to get them any lower I will have to reshape the sheetmetal. Can gas vapors enter cab thru wiper motor?

Beaver53,

I am not 100% on this, but will say vapors would never make it through the vacuum wiper motor, its little valve, through the chamber vent and into the cab. Under normal operation, this system is under negative pressure, or vacuum.

The only time this could conceivably happen would be when the truck was not running, and that isn't likely to happen.

A penetration through the firewall would allow engine compartment vapors to enter. See if any holes aren't plugged.

Stuart