Air cleaner vacuum lines

Chumley · 01-01-2007, 04:47 PM

Here's another one for you guys. I know how a thermastatic controlled air cleaner works. On this '72 model, it is currently not hooked up. The vacuum line from the manifold to the little plastic fitting which routes the vacuum to the thermastatic sensor is missing. There are 2 hose fittings on this piece. Where do the hoses go from this location? I'm used to there only being one, which would go to a manifold vacuum source. Until I get my assembly manual, I'm in the dark on some of this stuff. Thanks in advance.......Chumley

Oldsfan · 01-02-2007, 06:08 AM

Seems to me the line from your vacuum source runs to one of the ports on the sensor in the air cleaner housing. Other line from the other port on the housing to the vacuum motor out on the snorkel. I'm sure it makes a difference which ports on the sensor the hoses are connected to. Don't know if the sensor is marked or not.

Paul

Chumley · 01-02-2007, 09:19 AM

Thanks, There is already a line going from the sensor to the diaphram on the snorkel, as well as one going from the sensor to the part I was describing that has 2 vacuum fittings on one end, and 1 fitting on the other end(which goes to the sensor) I guess I could hook up a line to each and see if they both work or not, then plug the other one. All the other GM's I've owned just had one vacuum hose going from the intake to the sensor, then one hose from the sensor to the diaphram. OR, I could skip the middleman and just hook it up directly to the manifold. Since I'm running this motor stock, it would sure help on the cold mornings if this system was functional.

Chumley

Oldsfan · 01-03-2007, 05:38 AM

Sorry, I didn't read good enough. Missed the extra piece there. I'm looking at a '71 shop manual, cuz that's all I have in front of me right now, and it only shows a line from the intake to the air cleaner sensor and from the sensor out to the diaphragm on the snorkel. No extra piece. I can't imagine '72 would be any different. I'd remove it. Do you know the sensor in the air cleaner is any good? Maybe it's bad and they installed the extra piece to get things working, but that doesn't explain the hanging line...

Paul

Oldsguy · 01-03-2007, 06:00 AM

Sounds like there are two different sources for vacumm depending on engine conditions. I have never seen one like that though, especially on an older car. Is it possible that the previous owner neeeded to replace the lower air cleaner housing for some reason and got one from a newer car which uses computer control and two different sources of vacumm???? Just a thought.

Oldsfan · 01-03-2007, 06:08 PM

I just checked my '72 shop manual, and it, too, does not show this third piece of which you speak. Just shows the vacuum source running straight from the intake to the sensor.

Paul

01-01-2007, 04:47 PM	#1 (permalink)
Chumley Senior Member Join Date: Dec 2005 Posts: 138	Air cleaner vacuum lines Here's another one for you guys. I know how a thermastatic controlled air cleaner works. On this '72 model, it is currently not hooked up. The vacuum line from the manifold to the little plastic fitting which routes the vacuum to the thermastatic sensor is missing. There are 2 hose fittings on this piece. Where do the hoses go from this location? I'm used to there only being one, which would go to a manifold vacuum source. Until I get my assembly manual, I'm in the dark on some of this stuff. Thanks in advance.......Chumley

01-03-2007, 06:00 AM	#5 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 2,553	Sounds like there are two different sources for vacumm depending on engine conditions. I have never seen one like that though, especially on an older car. Is it possible that the previous owner neeeded to replace the lower air cleaner housing for some reason and got one from a newer car which uses computer control and two different sources of vacumm???? Just a thought. __________________ Dan '46 2 door

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01-02-2007, 06:08 AM	#2 (permalink)
Oldsfan Senior Member Join Date: Jul 2006 Posts: 427	Seems to me the line from your vacuum source runs to one of the ports on the sensor in the air cleaner housing. Other line from the other port on the housing to the vacuum motor out on the snorkel. I'm sure it makes a difference which ports on the sensor the hoses are connected to. Don't know if the sensor is marked or not. Paul

01-02-2007, 09:19 AM	#3 (permalink)
Chumley Senior Member Join Date: Dec 2005 Posts: 138	Thanks, There is already a line going from the sensor to the diaphram on the snorkel, as well as one going from the sensor to the part I was describing that has 2 vacuum fittings on one end, and 1 fitting on the other end(which goes to the sensor) I guess I could hook up a line to each and see if they both work or not, then plug the other one. All the other GM's I've owned just had one vacuum hose going from the intake to the sensor, then one hose from the sensor to the diaphram. OR, I could skip the middleman and just hook it up directly to the manifold. Since I'm running this motor stock, it would sure help on the cold mornings if this system was functional. Chumley

01-03-2007, 05:38 AM	#4 (permalink)
Oldsfan Senior Member Join Date: Jul 2006 Posts: 427	Sorry, I didn't read good enough. Missed the extra piece there. I'm looking at a '71 shop manual, cuz that's all I have in front of me right now, and it only shows a line from the intake to the air cleaner sensor and from the sensor out to the diaphragm on the snorkel. No extra piece. I can't imagine '72 would be any different. I'd remove it. Do you know the sensor in the air cleaner is any good? Maybe it's bad and they installed the extra piece to get things working, but that doesn't explain the hanging line... Paul

01-03-2007, 06:08 PM	#6 (permalink)
Oldsfan Senior Member Join Date: Jul 2006 Posts: 427	I just checked my '72 shop manual, and it, too, does not show this third piece of which you speak. Just shows the vacuum source running straight from the intake to the sensor. Paul