A/c Vacuum Lines Under Hood - The 1947 - Present Chevrolet & GMC Truck Message Board Network

eedgell · 04-24-2007, 12:28 AM

My 71 cheyenne has factory air, but all the vacuum lines are gone. I have nothing to start with under hood. Any body know where to find a diagram?

eedgell

lbpd719 · 04-24-2007, 01:15 AM

I recently bought a Factory Assembly manual, and have been impressed at the data it has given me.

I will be undertaking the same task soon.. maybe we should work together on it via the board.

67CHIP72 · 04-24-2007, 01:23 AM

I too have only a few parts remaining under my hood of the factory AC and want to gather the rest. I wil watch this post for info. Don't know if it is better to find a donor truck or just find and buy the missing parts.

lbpd719 · 04-24-2007, 01:28 AM

from what I can tell most of mine are there (thankfully) they are just disconnected. What parts are you missing and I will keep an eye out..

JimKshortstep4x4 · 04-24-2007, 04:26 AM

eedgell,

Here are pics of the vacuum diagrams. The first one should be like your 71 but I am posting the second pic just in case your truck has the three port vacuum control.

Jim

sneakysnake · 04-24-2007, 09:46 AM

http://67-72chevytrucks.com/vboard/s...d.php?t=225592

paaw · 04-24-2007, 06:15 PM

fixing to put my compressor back on, do all these vaccum lines have 2 b hooked up for it to come on

JimKshortstep4x4 · 04-24-2007, 07:54 PM

With the AC controls turned on and the blower switch on, the compressor should run. Ignition switch has to be on, also.

Here is the wiring diagram for reference.

Jim

eedgell · 04-27-2007, 11:15 PM

Thanks again for all the help. It seems in my case that the a/c works as far as compressor and making cold air, just the vacuum controled vents and things dont work cause they are not hooked up. There are no vacuum lines forward of fire wall, but every thing else works well. Inside/outside vent control, maybe something to do with a heater flow shut off?????

eedgell

04-24-2007, 12:28 AM	#1
eedgell It's the air up here Join Date: Mar 2007 Location: Western Colorado Posts: 710	A/c Vacuum Lines Under Hood My 71 cheyenne has factory air, but all the vacuum lines are gone. I have nothing to start with under hood. Any body know where to find a diagram? eedgell

04-24-2007, 01:15 AM	#2
lbpd719 Zappaphile! Join Date: Apr 2007 Location: Los Banos, California Posts: 228	Re: A/c Vacuum Lines Under Hood I recently bought a Factory Assembly manual, and have been impressed at the data it has given me. I will be undertaking the same task soon.. maybe we should work together on it via the board. __________________ 1969 C20 LWB Camper Special - The Beater.. 1998 Cheyenne V6 - 4/6 Drop - For The Son

04-24-2007, 01:23 AM	#3
67CHIP72 STOLEN Join Date: Jun 2006 Location: Orange County Posts: 1,022	Re: A/c Vacuum Lines Under Hood I too have only a few parts remaining under my hood of the factory AC and want to gather the rest. I wil watch this post for info. Don't know if it is better to find a donor truck or just find and buy the missing parts. __________________ In Search Of

04-24-2007, 01:28 AM	#4
lbpd719 Zappaphile! Join Date: Apr 2007 Location: Los Banos, California Posts: 228	Re: A/c Vacuum Lines Under Hood from what I can tell most of mine are there (thankfully) they are just disconnected. What parts are you missing and I will keep an eye out.. __________________ 1969 C20 LWB Camper Special - The Beater.. 1998 Cheyenne V6 - 4/6 Drop - For The Son

04-24-2007, 04:26 AM	#5
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: A/c Vacuum Lines Under Hood eedgell, Here are pics of the vacuum diagrams. The first one should be like your 71 but I am posting the second pic just in case your truck has the three port vacuum control. Jim Attached Images __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

04-24-2007, 09:46 AM	#6
sneakysnake It's a catastrophic success. Join Date: Jan 2003 Location: Oklahoma Posts: 2,077	Re: A/c Vacuum Lines Under Hood http://67-72chevytrucks.com/vboard/s...d.php?t=225592

04-24-2007, 06:15 PM	#7
paaw Registered User Join Date: Feb 2006 Location: nashville Posts: 217	Re: A/c Vacuum Lines Under Hood fixing to put my compressor back on, do all these vaccum lines have 2 b hooked up for it to come on __________________ 1997 pontiac grand prix gt (daily driver) for now; 2004 dodge ram quad cab (wife's truck) 4.7; 2000 pontiac booneville (wife daily driver) 1972 chevy cheyenne 350 bored 40 over 700r trans 373 gears ( posi) soon to be daily driver; 2002 gsxr750 sold

04-24-2007, 07:54 PM	#8
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: A/c Vacuum Lines Under Hood With the AC controls turned on and the blower switch on, the compressor should run. Ignition switch has to be on, also. Here is the wiring diagram for reference. Jim Attached Images __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC Last edited by JimKshortstep4x4; 04-24-2007 at 07:55 PM. Reason: Added wording

04-27-2007, 11:15 PM	#9
eedgell It's the air up here Join Date: Mar 2007 Location: Western Colorado Posts: 710	Re: A/c Vacuum Lines Under Hood Thanks again for all the help. It seems in my case that the a/c works as far as compressor and making cold air, just the vacuum controled vents and things dont work cause they are not hooked up. There are no vacuum lines forward of fire wall, but every thing else works well. Inside/outside vent control, maybe something to do with a heater flow shut off????? eedgell Last edited by eedgell; 04-27-2007 at 11:16 PM.



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