A/C vacuum actuator motors

Having pulled out my A/C for refurb i have found 2 vacuum motors. One has "OK12" stamped on it and the other has "OK14" stamped on it. Both motors look the same.

Are both vacuum motors the same? and do the same job in differant places

I believe one of them is a two stage vacuum motor. Go to the Classic Auto Air website to download a catalog specific to 71-73 Mustangs. I've used them several times with very good results. Chuck

Having pulled out my A/C for refurb i have found 2 vacuum motors. One has "OK12" stamped on it and the other has "OK14" stamped on it. Both motors look the same.

Are both vacuum motors the same? and do the same job in different places

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As you face the airbox installed in the car, there are four vacuum actuators on the A/C air box. On near the vent hole on the right end. One in the left center and a two stage on left side actually attached to the blower motor casing and another single stage on the opposite side of the blower housing..

I believe one of them is a two stage vacuum motor. Go to the Classic Auto Air website to download a catalog specific to 71-73 Mustangs. I've used them several times with very good results. Chuck

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+1 On Classic Auto Air.  Great resources online and in person. 

BTW- be very careful when dealing with the vacuum switch on your heater control as they become very brittle with age.  Yep, that was the voice of expeience!  :whistling:

Having pulled out my A/C for refurb i have found 2 vacuum motors. One has "OK12" stamped on it and the other has "OK14" stamped on it. Both motors look the same.

Are both vacuum motors the same? and do the same job in differant places

Click to expand...

As you face the airbox installed in the car, there are three vacuum actuators on the A/C air box. On near the vent hole on the right end. One in the left center and a two stage on left side actually attached to the blower motor casing.

Click to expand...

Thanks Rakerm. The blower motor in still in situ so i still got to remove that one. Is that blower motor held by 2 screws?

Having pulled out my A/C for refurb i have found 2 vacuum motors. One has "OK12" stamped on it and the other has "OK14" stamped on it. Both motors look the same.

Are both vacuum motors the same? and do the same job in differant places

Click to expand...

As you face the airbox installed in the car, there are three vacuum actuators on the A/C air box. On near the vent hole on the right end. One in the left center and a two stage on left side actually attached to the blower motor casing.

Click to expand...

Thanks Rakerm. The blower motor in still in situ so i still got to remove that one. Is that blower motor held by 2 screws?

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I dont recall exactly how many bolts/mounts, but from the pictures I see two.

As you face the airbox installed in the car, there are three vacuum actuators on the A/C air box. On near the vent hole on the right end. One in the left center and a two stage on left side actually attached to the blower motor casing.

Click to expand...

Thanks Rakerm. The blower motor in still in situ so i still got to remove that one. Is that blower motor held by 2 screws?

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I dont recall exactly how many bolts/mounts, but from the pictures I see two.

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Pictures were a great help. I stripped out centre bezel to get a better view. Found the 2 screws and removed the blower motor screws. Found 2 more vacuum motors and some repair needs to be done

Well, that makes four vacuum actuators and not three as I had previously stated. Only one is a dual vacuum.

Is it an AC car?  I'm trying to figure out why I'm not blowing Cold Air, only cool (new classic air compressor and all new parts in the engine bay) I even replaced the switch that shuts off the heater hose when the AC is turned on. So, I'm thinking that there is a flap that directs the air to either the heater core or the AS coil. But haven't been able to find anything referencing this.

Sorry for the Hi-Jack.

Section 36-32 of the Ford Shop Manual describes how it all works and has good illustrations. The control knob actuates the various vacuum motors, shuts off the hot water, and turns the a/c compressor on. All it takes is failure of one item, like a leaking vacuum hose or blown fuse to keep it from functioning.

Section 36-32 of the Ford Shop Manual describes how it all works and has good illustrations. The control knob actuates the various vacuum motors, shuts off the hot water, and turns the a/c compressor on. All it takes is failure of one item, like a leaking vacuum hose or blown fuse to keep it from functioning.

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Great imput Don.

How well do the vacuum motors stand the test of time? Are they reliable or do they have a finite lifetime of work?

I am tempted getting my vacuum motors tested to see if they are still working. As i stated before i only want to do my A/C once so don't want to re-install vacuum motors if theres a chance they will fail in future

If they are original I would say they have outlived their useful life span by many years. Due to the time involved in removing and installing a heater-a/c box I would replace or rebuild everything, including the blower motor.

The way I look at these things is what is the value of my time times how long it will take, and then compare it to the out-of-pocket expenses of doing the right thing.

Didnt even consider stripping the blower motor. Good call. Is there any particular part i need to focus on Don?

You can test the vacuum accuators with a brake bleeder/vacuum pump. All but my dual diagram motor worked. To save a few bucks I decided to replace the ones that were hard to get to with the airbox installed. A few are easy to get to later. So far no problems with the old ones.

Vacuum motors suck.   Ask me how I know.

For the blower motor, the brushes and clean and grease the bushings. The brushes are usually the first to wear out, I don't know if it would be possible to find replacements, maybe an automotive electrical repair shop.

For the blower motor, the brushes and clean and grease the bushings. The brushes are usually the first to wear out, I don't know if it would be possible to find replacements, maybe an automotive electrical repair shop.

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There many types of brushes on amazon and eBay. If not there then try http://store.eurtonelectric.com/brushes.aspx. They have just about every type of motor brush.