Hi I have a leaking carburetor on my Chevy 3100. I cannot tell if it is the fuel line in ( I suspect that) or something else. Truck runs great but this leak is a hazard. I am thinking of replacing the line between filter and carb. see picture attached. I am also thinking of rebuilding carb but am not sure how to identify which carb I have? Suggestions? Thanks, Denis Also I am not sure why my profile picture does not show?
carb leak Easy way to see where the leak is to blow the area dry with compressed air and see where it gets wet again. Hard to tell from teh picture since everything there looks wet. I am not sure which carby you have there either Im sure someone else will chime in and help with that(Nate) One thing I learned is that the top of the carby (called the airhorn) has to be tightened down evenly as in the screws have to be torqued to the same torque or you will warp the airhorn and it wil stall each and everytime you stop ata light or stop sign and drive you batty.
It appears to be a Rochester Carb, period correct. Nate calls them Rottenchesters. They all seem to leak at that Air Horn Gasket as the Air horn does warp. I had to put two gaskets there and that helped a lot. The leaking is something the boys say you must learn to live with. I agree its scary there over the exhaust manufold. If you have the bucks a NOS or rebuilt might leak less. The usual thing is to keep tightening again and again and really only increase the warpage even more...don't. Flashlight
Thanks two terrific tips. I will clean it and dry it to see if leak is apparent. Also thanks for IDing the carb! Denis
Rodchester B The Rodchester B comes in 2 sizes. the smaller is for the 216-ci and the larger for the 235-ci. The ones found on car usually have automatic choke. The parts kit you find may have gaskets for both. I would get the glass bowl fuel filter and mount it in front of the carb. That way you don't have to use a rubber hose. A new piece of metal fuel line bent correctly will looks like a 10E5 bucks with the new fuel bowl.
Hey, Willard where you been? On your note, as our buddies from deutschland found out, the different sizes are not only cfm but the mounting holes/insulators are different widths. Can be expensive and frustrating! Flashlight
I'm Late ! But you guys have it all figured out . danmpness at the bowl gasket is normal . I've never used two gaskets , if you do so , remember to re - adjust the float level down a bit , you measure it from the gasket surface , NOT the metal air horn .
Nate glad your up an at em". You know I didn't know that and I've had a float sticking issue on one of my carbs. Do you recall the distance to measure down from? Flashlight
Float Adjustment Wal now , there's the Factory Shop Manual way , then there's the GM Dealer Training way........ I always hold the air horn in one hand so it's vertical , float dangling by it's pin , then I tip it a bit thisa-way & that until I can see where the float's tang just touches the needle valve , ideally at this point the float is hanging straight down . The really cool part is : this trick works on everything from Lawn Mowers to Ferraris , Porsches , Mercedes , old pre war Riley's , hell , even a wretched GMC I suppose .
Thanks all, I think the right approach is to attempt a rebuild as the leak is more than dampness. I hate to do it becuse it runs and starate so well. Maybe I should just replace gaskets. Denis
Waitaminnit ! I'm not sure you're familiar with just how wet is permissable in a Rochester Series 'B' carby ~ unless there are droplets running down the engine , it's good to go ~ I know this because you didn't complain about the headaches from fuel stink nor bad fuel economy . If it's running well , I'd consider leaving it alone . You _could_ remove the air cleaner and get some cotton cloths & a bottle of Isopropal alcohol from the .99 Store ansd wipe off those stains , then run it some more and see how it goes . Fiddling with a 50 year old carby that's making the engine run fine , isn't wise IMO . The pictures you've posted show the normal situation on old Chevy's ~ remember too that winter blended fuels weep and evaporate more & so make the stains worse.. Remember : ' CARBURATOR is a French word that means : LEAVE IT ALONE ! .
Ok I think I will run it a bit longer and see. I do smell fuel in the cab but it is not terrible. Thanks, Denis
