MO WTB: air cleaner vacuum motor for 72 350

[Ozark Tim]

I need the vacuum motor that is mounted to the air intake on the base section of the air cleaner that opens and closes the door determining if the engine recieves hot air of the stove or not.
I cant find one locally at a parts store like I have in the past and need one.
Any body have one of these that they can check to make sure it holds vacuum or maybe even a whole air cleaner base if necessary?
Thanks,
Tim

[425HP409]

They are all the same part on all GM air cleaners. You should be able to find one off of a non PU air cleaner cheap and use it. If you can't find one locally, I have one you can have.
Charles

[Ozark Tim]

Thanks Charles!
I'll have to try to stop by a local salvage yard to see if I can find a good one and if not I may have to take you up on that offer!
Tim

[69-72]

I got mine from http://www.thepartsplaceinc.com Look up Part# CW8422Z it is $19.00

I think they are the only place that sells them new. I just hooked mine up last week and it makes a night and day difference. Runs much smoother.

Do you happen to have any extra stove pipes for sale?

[badpeanut]

Originally Posted by 69-72

I got mine from http://www.thepartsplaceinc.com Look up Part# CW8422Z it is $19.00

I think they are the only place that sells them new. I just hooked mine up last week and it makes a night and day difference. Runs much smoother.

Do you happen to have any extra stove pipes for sale?

Does this one fit our trucks (is the vacuum port timed properly in relation to the angle hook)?

Today I got one from the junk yard off an 1985 Caprice but the vacuum port is timed wrong.

[69-72]

What do you mean by timed wrong?

[DANTIP]

I have used this exact part and it works perfectly. The only difficulty with the change-out was bending the tab that holds the diaphragm down. You have to somehow reach inside the snout and bend the tab (not easy).

FYI, it is east to test the function of an existing diaphragm with a hand-held vacuum pump. My experience is around 50% of them work properly. Also, I have been told the diaphragm can tolerate the temperatures needed for powder coating. Has anyone tried one?

[69-72]

On mine the tab just hooked in on one side and I spot welded (plug weld mig) the other side. The motor is set to work at 120f or something so it withstands that at least, depends what temp powder coating is done at I guess.

I was told by the Parts Place that these motors are NOT supposed to hold vacuum. Not sure if that is right but when you test it, it should move the rod but leak down after.

[badpeanut]

Originally Posted by 69-72

What do you mean by timed wrong?

The 1985 Caprice thermac is pictured. The relative angle/clocking/timing between the vacuum fitting and flapper door hook is off 90° so the vacuum fitting ends up on the passenger side of the snorkel rather than the driver side.

Originally Posted by DANTIP

I have used this exact part [Parts Place part# CW8422Z] and it works perfectly. The only difficulty with the change-out was bending the tab that holds the diaphragm down. You have to somehow reach inside the snout and bend the tab (not easy).

Does the Parts Place thermac come with a straight wire end (no 90° bend like I have pictured)?

After I drilled out the two spot welds holding one end the sheet metal retainer in place and unhooked the other end to remove it, I lifted the thermac up slightly and slid it over to disengage the hook from the flapper door in the snorkel.

Originally Posted by 69-72

I was told by the Parts Place that these motors are NOT supposed to hold vacuum. Not sure if that is right but when you test it, it should move the rod but leak down after.

This is my understanding also.

------------------------------

Maybe I should try straightening out the wire end and rebending it at the correct angle/clocking/timing relative to the vacuum fitting?

[69-72]

The Parts Place one came with a straight wire.

On a side note, it is amazing how much these things help with performance. Before I installed mine between every shift the engine would bog down, now it is smooth.

[badpeanut]

Attached is a picture of the correct thermac. Note the relative angle/clocking/timing between the vacuum fitting and flapper door hook/mounting tabs; it is about 90° different than the 1985 Caprice thermac I posted earlier.

Is the http://www.thepartsplaceinc.com thermac like the 1972 GMC thermac or like the 1985 Caprice thermac?

[69-72]

Originally Posted by badpeanut

Is the http://www.thepartsplaceinc.com thermac like the 1972 GMC thermac or like the 1985 Caprice thermac?

The door hook comes straight, you have to bend it which ever way you want it. I cant remember the exact position of the tabs but installed on my 72 it looks the same as stock. The vac pipe points the correct way.

[badpeanut]

Originally Posted by 69-72

The vac pipe points the correct way.

I'll have to order one of those then. Leaving the hook the way it is on the Caprice thermac puts the vac pipe 90° counterclockwise to the original pickup vac pipe so it is on the wrong side of the air cleaner intake. Rebending the hook on the Caprice thermac puts the vac pipe 90° clockwise to the original pickup vac pipe (the mounting tabs are limiting) so it is at least on the correct side of the air cleaner intake but will require a longer hose because it is pointed away. The Caprice thermac will function, but it bugs me because it isn't exactly as the original.

[badpeanut]

http://www.thepartsplaceinc.com sent me this picture confirming it is 100% correct for our trucks: