Rochester B leaking between bowl and horn... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**jabborabbo** · 05-05-2019, 04:55 PM

I rebuilt the carb about a year ago, torqued the screws attaching the horn to the bowl to 70 in-lbs, and haven’t had any problems until today (at least noticeable problems). There was a bit of gas around the gasket (I smelled it before I found it)...The screws weren’t at 70 in-lbs - I re-torqued them and they turned maybe 20 -30 degrees before they were at 70 in-lbs. Is it typical for these carbs to loosen up like that over time?

**kidatheart** · 05-05-2019, 05:06 PM

I’m no mechanic but I would guess the gasket might have shrunk from heat and time. The bolts didn’t loosen-the gasket got thinner.

**Jason Banks** · 05-05-2019, 05:11 PM

Whatever is happening mine does it too...I have a 68 with the monojet, not the B, but I'm constantly tightening the screws on top to stop leaking. I have several of the monojet carbs, but one of the NOS rebuilt ones I got had double gaskets.

**Steeveedee** · 05-05-2019, 11:43 PM

That's a problem with newer kits. Back in the day, you could rebuild a carburetor and expect good performance for many years. If it isn't flooding and blowing black smoke, your float level and float are OK. Just re-tighten the screws when needed.

**jabborabbo** · 05-06-2019, 06:45 PM

Thanks to all!

05-05-2019, 04:55 PM	#1
jabborabbo Senior Member Join Date: Apr 2013 Location: Podunk, Texas Posts: 762	Rochester B leaking between bowl and horn... I rebuilt the carb about a year ago, torqued the screws attaching the horn to the bowl to 70 in-lbs, and haven’t had any problems until today (at least noticeable problems). There was a bit of gas around the gasket (I smelled it before I found it)...The screws weren’t at 70 in-lbs - I re-torqued them and they turned maybe 20 -30 degrees before they were at 70 in-lbs. Is it typical for these carbs to loosen up like that over time? __________________ "It is hard to search for a black cat in a dark room, particularly if it is not there. Especially if this cat is smart, brave, and polite." Sergei Shoigu, Russian Minister of Defense

05-05-2019, 05:06 PM	#2
kidatheart Senior Member Join Date: May 2012 Location: Assaria, Ks Posts: 465	Re: Rochester B leaking between bowl and horn... I’m no mechanic but I would guess the gasket might have shrunk from heat and time. The bolts didn’t loosen-the gasket got thinner.

05-05-2019, 05:11 PM	#3
Jason Banks Senior Member Join Date: Dec 1999 Location: TX Posts: 1,623	Re: Rochester B leaking between bowl and horn... Whatever is happening mine does it too...I have a 68 with the monojet, not the B, but I'm constantly tightening the screws on top to stop leaking. I have several of the monojet carbs, but one of the NOS rebuilt ones I got had double gaskets.

05-05-2019, 11:43 PM	#4
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,676	Re: Rochester B leaking between bowl and horn... That's a problem with newer kits. Back in the day, you could rebuild a carburetor and expect good performance for many years. If it isn't flooding and blowing black smoke, your float level and float are OK. Just re-tighten the screws when needed. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

05-06-2019, 06:45 PM	#5
jabborabbo Senior Member Join Date: Apr 2013 Location: Podunk, Texas Posts: 762	Re: Rochester B leaking between bowl and horn... Thanks to all! __________________ "It is hard to search for a black cat in a dark room, particularly if it is not there. Especially if this cat is smart, brave, and polite." Sergei Shoigu, Russian Minister of Defense

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