Rochester 4 bbl carb squeal - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ChevykidHB · 11-06-2013, 12:56 AM

hey guys got a 350 with the Rochester 4 barrel. and its got what i though was a belt squeal but turns out its the carb? time for a rebuild? or is it just a vacuum line? thanks!

Twisted78SS · 11-06-2013, 01:04 AM

Ya know, I think I have one of those too,

Thought maybe it was just me.. Mine is a brand new old stock Edelbrock quadrajet. Not sure what to do about it, can't find any leakes etc..

ChevykidHB · 11-06-2013, 01:10 AM

i have a feeling its a vacum leak but i dont know much about carbs at all. im learning as i go. my secondaries also seem to not open which makes me think it might be a vacum leak.

ChevykidHB · 11-09-2013, 10:45 PM

scratch all that. was the belt. swap yours out if you haven't already

swamp rat · 11-10-2013, 01:09 AM

Quote:

Originally Posted by ChevykidHB

scratch all that. was the belt. swap yours out if you haven't already

That's funny as hell, i had a belt squeal that was driving me nuts, i was blaming the alternator bracket alignment, alternator pulley, and even the water pump pulley alignment even tho i had seen worse alignment not squeal at all, tried 3 different belts too, turned out it was an unplugged vacuum line on the back of the carb.

ChevykidHB · 11-10-2013, 01:30 AM

haha right on it was really driving me crazy for a few weeks until i finally got it

Twisted78SS · 11-10-2013, 01:37 AM

Well,

Can't blame the belts on mine, I ran it without any belts at all as a means to eliminate them.. Still have a sqeel / squeak.. Vacuum gauge doesn't indicate a leak that I can pinpoint..

Not sure what to do next. Only happens a 1/2 3/4 throttle

**bigmac73** · 11-10-2013, 06:59 AM

sounds like it is just air flow going into the air horn on the top of carb, i had a 72 with a 307 before and every time you downshifted and stomped it , it would made a squeak or whine sucking air in,does it happen with the air cleaner off??

swamp rat · 11-10-2013, 12:54 PM

Woops, i stand corrected, it was the port on the manifold for the transmission not a port on the carb, i had used the port on the carb then forgot to plug the fitting on the manifold.. so i plugged the carb port and went back to the manifold port and problem solved.

ChevykidHB · 11-11-2013, 06:51 PM

damit! spoke to soon. i tested it out again today and it still making that squeal with and with out the air cleaner. what did you do to fix the carb on the 307?

11-06-2013, 12:56 AM	#1
ChevykidHB Registered User Join Date: Oct 2013 Location: Huntington Beach, California Posts: 18	Rochester 4 bbl carb squeal hey guys got a 350 with the Rochester 4 barrel. and its got what i though was a belt squeal but turns out its the carb? time for a rebuild? or is it just a vacuum line? thanks! __________________ 1970 c20 cst 350/400 14bolt rear

11-06-2013, 01:04 AM	#2
Twisted78SS Wide n'Low Join Date: Jan 2007 Location: La Center, WA Posts: 1,511	Re: Rochester 4 bbl carb squeal Ya know, I think I have one of those too, Thought maybe it was just me.. Mine is a brand new old stock Edelbrock quadrajet. Not sure what to do about it, can't find any leakes etc.. __________________ Trippin Hazard.. 67 swb, Gold Member.. 68 Suburban Air Force Retired

11-06-2013, 01:10 AM	#3
ChevykidHB Registered User Join Date: Oct 2013 Location: Huntington Beach, California Posts: 18	Re: Rochester 4 bbl carb squeal i have a feeling its a vacum leak but i dont know much about carbs at all. im learning as i go. my secondaries also seem to not open which makes me think it might be a vacum leak. __________________ 1970 c20 cst 350/400 14bolt rear

11-09-2013, 10:45 PM	#4
ChevykidHB Registered User Join Date: Oct 2013 Location: Huntington Beach, California Posts: 18	Re: Rochester 4 bbl carb squeal scratch all that. was the belt. swap yours out if you haven't already __________________ 1970 c20 cst 350/400 14bolt rear

11-10-2013, 01:30 AM	#6
ChevykidHB Registered User Join Date: Oct 2013 Location: Huntington Beach, California Posts: 18	Re: Rochester 4 bbl carb squeal haha right on it was really driving me crazy for a few weeks until i finally got it __________________ 1970 c20 cst 350/400 14bolt rear

11-10-2013, 01:37 AM	#7
Twisted78SS Wide n'Low Join Date: Jan 2007 Location: La Center, WA Posts: 1,511	Re: Rochester 4 bbl carb squeal Well, Can't blame the belts on mine, I ran it without any belts at all as a means to eliminate them.. Still have a sqeel / squeak.. Vacuum gauge doesn't indicate a leak that I can pinpoint.. Not sure what to do next. Only happens a 1/2 3/4 throttle __________________ Trippin Hazard.. 67 swb, Gold Member.. 68 Suburban Air Force Retired

11-10-2013, 06:59 AM	#8
bigmac73 Senior Member Join Date: Mar 2012 Location: Chesapeake, Va Posts: 1,275	Re: Rochester 4 bbl carb squeal sounds like it is just air flow going into the air horn on the top of carb, i had a 72 with a 307 before and every time you downshifted and stomped it , it would made a squeak or whine sucking air in,does it happen with the air cleaner off?? __________________ Mike 72 C-10 Cheyenne off frame resto and Upgraded to 4 wheel disk, Tilt, Dakota Digital Dash / Rear slider. 421 SBC / TH350 3000RPM Stall Progression Ignition /Holley 750 DP/3:73 gear Eaton Limited Slip unit / 2 1/2 exhaust glasspacks

11-10-2013, 12:54 PM	#9
swamp rat Registered User Join Date: Oct 2007 Location: Spanaway Posts: 8,451	Re: Rochester 4 bbl carb squeal Woops, i stand corrected, it was the port on the manifold for the transmission not a port on the carb, i had used the port on the carb then forgot to plug the fitting on the manifold.. so i plugged the carb port and went back to the manifold port and problem solved. __________________ Mike. Swamp Rat build thread : http://67-72chevytrucks.com/vboard/s...d.php?t=595019 72 3/4T 4X4 4" BDS Lift 33" BFG's

11-11-2013, 06:51 PM	#10
ChevykidHB Registered User Join Date: Oct 2013 Location: Huntington Beach, California Posts: 18	Re: Rochester 4 bbl carb squeal damit! spoke to soon. i tested it out again today and it still making that squeal with and with out the air cleaner. what did you do to fix the carb on the 307? __________________ 1970 c20 cst 350/400 14bolt rear

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.