Answer to Rochester fuel leak.

[Greg S]

I have been plagued with a strong gasoline smell when I turn right. Doesn't have to be a that sharp of a turn with squealing tires or anything, just sharp enough to feel a bit of a pull to the left. Last year I thought it was a leak in my newly rebuilt gas tank. Nope! Put a hole in my tank so removed it and have been using a boat tank since. Definately not the missing tank so thought it was now from the vent in the lid of the boat tank (inside the car). Nope! closed the vent entirely and still smelled the gas. Lots of people suggested the float chamber overflow. Nope! That's contained in the air intake and the fuel is burned in the cylinders.

I finally pulled into my driveway rather fast, jumped out and lifted the bonnet (hood) to see gasoline dripping off the linkage onto the manifold. It evaporates quickly and hasn't been leaving a stain so it's hard to see it after the evaporation. (Something to be said for running marked gas.) I pulled the carb apart to investigate and found it's the push rod for the accelerator pump. Fuel sloshes to the top of it and runs down the slot. It's rectangular so an O ring won't fix it. I disconnected the pump piston rod from the shaft and put a finger cut out of a rubber glove over the assembly and zip tied it around the base of the tower of the accel shaft, then put the piston rod and spring back, right over the rubber finger tip. FIXED! or at least it seems so. I wonder how long the glove will last.

That gasoline smell has been driving me nuts for a year. If anyone else has a fix for it, please let me know because I don't know how long the rubber finger will last.

[rezdiver]

Greg,
I am not familiar with the setup but i would assume that if the gas is in contact with the rubber glove it will expand the rubber and deteriorate and it will fall apart, hopefully not into anyplace where it will cause a blockage. I think any viton material would last with exposure to gasoline.

[Greg S]

The glove is Nitrile. Latex gloves fall apart at the mere sight of a chemical. Makes me wonder why they'd use them for blood borne pathogens. I was thinking if the Nitrile gloves works okay for a while, I'd try thin surgical tubing, but isn't that latex too? Would it fall apart like the gloves?

[ssortnarg]

Greg have you tried to source a kit for the carb-
PIERCE MANIFOLDS IN California have a great stock of kits and ship promptly .

[rezdiver]

some surgical tubing is not latex as they have to be used on persons with latex allergies, a home medical shop should have something like that for pretty cheap.

[Greg S]

Greg have you tried to source a kit for the carb-
PIERCE MANIFOLDS IN California have a great stock of kits and ship promptly .

I don't think it is a rebuild sort of thing, more like a design thing.

[Wastegate]

Hi Greg, Ive seen your clean 109 around town! Mostly at wendys :wink: I pulled apart my spare rochester and it appears that your main gasket is at fault?
http://i126.photobucket.com/albums/p90/ ... 8/carb.jpg
The part I believe you are speaking of is what im pointing at. The gasket that goes all around the bowls and such are supposed to seal off this area. If I remember yours is a fairly new reman one like mine. So maybe Im out too lunch but thats my thought. Thanks for that starter again :wink:
Tony

[Greg S]

Tony.
Yes, that's the spot! But the main gasket doesn't seem to come anywhere close to controlling any leak from there. The gasket goes right around this, and the piston return spring with a large rectangular hole. Maybe I should make a baffle for that opening.

Did you get that starter working okay? Was it a simple fix for the wire? The starter I put in to replace that one, has now failed and been replaced (last week). I think it failed by the long case machine screws backing out a bit, allowing the case to twist with the torque. Lesson learned "don't use Never-Seize on everything".

[Wastegate]

http://i126.photobucket.com/albums/p90/ ... GP4590.jpg
http://i126.photobucket.com/albums/p90/ ... GP4592.jpg
Ahh you are right, Well if that's the case I have no idea! I'm sorry haha. All I know is mine is not tight, I can see light through the accelerator rod. (Whats leaking). So is it possible your top has warped like a zenith? As for the starter yes new brushes and it worked like a top. However there is a slight difference in the mounting circle for the larger diesel starter so we had to drill and tap a new hole in the bellhousing but it work great every time! I plan on installing the original larger diesel one later after some "re-working" with the motor. Too bad about your other one but yes a very good lesson indeed!

[Wastegate]

Greg have you fixed this problem? Because I swapped my zenith off the tan 88 for my rochester and now it seems to leek from there as well! Not pouring out but wet

[Greg S]

Gee, I posted somewhere that I'd fixed it but obviously not here. Easy fix and it's lasted over a month now with no issues.

Take the finger from a blue Nitrile rubber surgical glove. (I'm sure there are other choices.)
Remove the rod and spring of the accelerator pump piston from the arm on the linkage.
Slip the finger over the entire linkage and the support, tie wrap it in place around the base of the support.
Re-install the rod and spring from the accelerator pump right over the rubber finger onto the linkage.
NO MORE Gas leak!