pollution controls, how to run the hoses - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mike16 · 12-15-2009, 07:54 PM

I got a 72 307 half ton with 3 speed. Alot of whats under the hood is origional. I want to keep it that way. What about polution controls. Mine is not an CA truck. I got a switch on the tranny sid cover that I thought was for back up lites...wrong Huh? and the electrically operated air valve thingie that goes between the vac advance and the carb and som evap canister. Its all there but whats it do, how do you test it for correct opps and how do you route the hoses correctly and if need be where are new NOS parts available.

Expound please.

**john** · 12-15-2009, 08:09 PM

Sounds lile you have TCS (transmission controlled spark) on your truck. The solenoid between the carb and vac advance allows advance only when in high gear. The trans switch controls it. It should also have a temp sender in the pass side head so it works only when up to oper. temp. Maybe someone has a vacuum diagram they can post.

mike16 · 12-16-2009, 12:30 AM

My truck is not a ca truck, it would NOT have had the AIR system as well would it. It does not seem to have.

toms68cst · 12-16-2009, 12:51 PM

From what I've seen, non calf trucks with manual transmission trucks had AIR systems from 68 up. I'm not sure which year they went away from AIR though. My Non calf 68 still has AIR. I don't have anything on my tranny related to smog control though.

cdowns · 12-16-2009, 01:34 PM

excellent diagrams of the charcoal recovery cannister routing are in the factory assembley manual most vendors can supply it for you at a reasonable price

mike16 · 12-17-2009, 02:23 AM

I'm fairly sure my truck did not have the AIR system on it. I got that factory assembly manual. but my truck is a 72 and there not alot on 72's in there or info on pulleys and brackets.

who has a parts manual for this 72 year truck? on Disk?

12-15-2009, 07:54 PM	#1
mike16 Registered User Join Date: Dec 2009 Location: bisbee, arizona Posts: 1,529	pollution controls, how to run the hoses I got a 72 307 half ton with 3 speed. Alot of whats under the hood is origional. I want to keep it that way. What about polution controls. Mine is not an CA truck. I got a switch on the tranny sid cover that I thought was for back up lites...wrong Huh? and the electrically operated air valve thingie that goes between the vac advance and the carb and som evap canister. Its all there but whats it do, how do you test it for correct opps and how do you route the hoses correctly and if need be where are new NOS parts available. Expound please.

12-15-2009, 08:09 PM	#2
john member #16 Join Date: Dec 1999 Location: Yuba City Ca. Posts: 3,618	Re: pollution controls, how to run the hoses Sounds lile you have TCS (transmission controlled spark) on your truck. The solenoid between the carb and vac advance allows advance only when in high gear. The trans switch controls it. It should also have a temp sender in the pass side head so it works only when up to oper. temp. Maybe someone has a vacuum diagram they can post. __________________ john http://67-72chevytrucks.com/vboard/showgroups.php board vendors http://www.flickr.com/photos/1745471...7602865984234/

12-16-2009, 12:30 AM	#3
mike16 Registered User Join Date: Dec 2009 Location: bisbee, arizona Posts: 1,529	Re: pollution controls, how to run the hoses My truck is not a ca truck, it would NOT have had the AIR system as well would it. It does not seem to have.

12-16-2009, 12:51 PM	#4
toms68cst Registered User Join Date: Jun 2000 Location: Bismarck, ND Posts: 4,282	Re: pollution controls, how to run the hoses From what I've seen, non calf trucks with manual transmission trucks had AIR systems from 68 up. I'm not sure which year they went away from AIR though. My Non calf 68 still has AIR. I don't have anything on my tranny related to smog control though. __________________ Unrestored 68 C-10 CST. Original 327. 4-Speed CH465. 50k or so miles. TREASURER, Drum Brake Club.

12-16-2009, 01:34 PM	#5
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: pollution controls, how to run the hoses excellent diagrams of the charcoal recovery cannister routing are in the factory assembley manual most vendors can supply it for you at a reasonable price __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

12-17-2009, 02:23 AM	#6
mike16 Registered User Join Date: Dec 2009 Location: bisbee, arizona Posts: 1,529	Re: pollution controls, how to run the hoses I'm fairly sure my truck did not have the AIR system on it. I got that factory assembly manual. but my truck is a 72 and there not alot on 72's in there or info on pulleys and brackets. who has a parts manual for this 72 year truck? on Disk?



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