[GMCnet] Homemade vacuum pump for air conditioning work

[Emery Stora]

It is very, very easy to make your own vacuum pump and very inexpensive.
Get a compressor from an old refrigerator or window air conditioner.

Hook an electrical cord to the wires. Remember that the black wire goes to the brass screw in the plug and the white wire goes to the chrome or silver screw. There is usually a green wire. That is the ground.


Run the compressor and put your finger over the tubes. The one that has suction is the one that you will use for your setup.

You can purchase a valve with the fitting for the hose from an air conditioner supply shop (or from the internet). Or you can just put on a 7/16" x 20 fitting for the R12 hose.

That's it.

Emery Stora
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[Thomas Phipps]

EmEry, funny you brought this subject up. I have a subscription to a British Eletronics mag, "EPE,", and the current copy, which came in the mail today discusses the exact same idea as part of their recycling column.
Great minds converging together.
Tom, MS II
--
1975 GMC Avion, under forever re-construction
Vicksburg, MS. 3.7 miles from I-20

[Jeff Marten]

If you have a shop/garage air compressor, Harbor Freight has a really cheap venturi vac pump that works fairly well. I think it was $14.99.

[anthony ezzo]

Em,I love this!!!! My Eldo got hit a few weeks back,so I bought this....

http://lakeland.craigslist.org/cto/3970816464.html


I am finally going to cut the hood and put the 2115 intake on the car and change the a-6 to a small sanden.I will need to suck it back down after and this is a great Idea.

I am going to save my 67 only hood and hack up this 68 hood and put a scoop on so it does not rain right in the motor.
--
77 455 Elaganza II and 67 Animal, Built 500 Powered Eldo

[Kelvin Dietz]

Yeah... those suck, Jeff.
But not in a good way.

Kelvin
'73 23' in Eugene, OR

[Mark]

Kelvin Dietz wrote on Thu, 15 August 2013 17:02

> Yeah... those suck, Jeff.
> But not in a good way.
>
> Kelvin
> '73 23' in Eugene, OR
>
> On 8/15/2013 4:54 PM, Jeff Marten wrote:
> > If you have a shop/garage air compressor, Harbor Freight has a really cheap venturi vac pump that works fairly well. I think it was $14.99.

I have one of those compressor-driven venturi vacuum units... they DO work, at least to a point, but require a crazy amount of air to run. They're more than adequate for pulling brake fluid through brake lines, but it's painful to try to pull a hard vacuum on an A/C system (which requires a long time at full vacuum). I'm getting ready to break a leaky line in my GMC's A/C line, which will require pulling a vacuum and re-filling (I'll be using the proverbial three cans of Duracool). I think I'll break down and buy a real vacuum pump this time... hope I can find one that's not too expensive...
--
Mark Hickey
Mesa, AZ
1978 Royale Center Kitchen

[Brian Pimm]

We have been using this pump for several years, seems to work good.

pump-98076.htmlhttp://www.harborfreight.com/25-cfm-vacuum-pump-98076.html

--
Brian & RaeDean

1973 26' #383

Washougal WA

[Emery Stora]

Yes, but a Venturi really won't suck down to a low enough vacuum. That thing is worthless. Don't waste your money.

Emery Stora

[Matt Colie]

bpimm wrote on Thu, 15 August 2013 21:09

> We have been using this pump for several years, seems to work good.
>

> http://www.harborfreight.com/25-cfm-vacuum-pump-98076.html

That level of pump is OK for a system that was good and being repaired. 75 Micron just is not enough hard vacuum to dry out a system that has been open for very long.

Try the local pawn shops first. The vacuum pump is something that people let go of easily.

Try for a 2 stage (~10 micron) and you won't regret the extra expense.

Matt - You don't want to know what I use.
--
Matt & Mary Colie
'73 Glacier 23 Chaumière (say show-me-air)
Now with 4 working Rear Brakes
SE Michigan - Twixt A2 and Detroit

[Ken Burton]

http://www.amazon.com/TMS-VP125-Rotary-Vane-Vacuum/dp/B006P7LBFK/ref=sr_1_14?ie=UTF8&qid=1376625782&sr=8-14&keywords=vacuum+pump


--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

[Rob Mueller]

Cryogenic / Ion? ;-)

Regards,
Rob M.

PS - to save Matt from responding - the pumps listed above are used to simulate vacuum levels in outer space by NASA.

-----Original Message-----
From: Matt Colie

That level of pump is OK for a system that was good and being repaired. 75 Micron just is not enough hard vacuum to dry out a
system that has been open for very long.

Try the local pawn shops first. The vacuum pump is something that people let go of easily.

Try for a 2 stage (~10 micron) and you won't regret the extra expense.

Matt - You don't want to know what I use.

[gene Fisher]

I have built 3 of the "refer"pumps so far
did :
- 2 gmc
- 1 Camino


and the hf air driven one "sucks" but not good enough to work

"side benefit"
you cannot take an old refer to the junk yard unless the freon is removed
-which is what happens when you remove the compressor :>)

gene\
-

--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html

[Jp Benson]

It's not a very good refrigeration/AC vacuum pump but handy for a lot of other things.  Here's the working part:


http://www.gmcmhphotos.com/photos/front-clip-april-2013/p48569-steering-box-flush-too.html

JP


>________________________________
> From: Emery Stora <emery...@me.com>
>To: "gmc...@temp.gmcnet.org" <gmc...@temp.gmcnet.org>
>Sent: Thursday, August 15, 2013 9:39 PM
>Subject: Re: [GMCnet] Homemade vacuum pump for air conditioning work

[brian]

is the compressor in my old ac/dc fridge any good for this?
--
brian
asheboro, nc
75 eleganza 2 74 build
118k miles and counting,
DOG HOUSE

[larry.whisler]

Has anyone used the compressor out of a working roof a/c unit for this?

larry

[Ken Henderson]

Larry,

I haven't actually done it, but any functional compressor should work.
Mine's a small one from a small ice maker.

Ken H.

[Brian Pimm]

Matt Colie wrote on Thu, 15 August 2013 18:55

> bpimm wrote on Thu, 15 August 2013 21:09
> > We have been using this pump for several years, seems to work good.
> >
> > http://www.harborfreight.com/25-cfm-vacuum-pump-98076.html
>
> That level of pump is OK for a system that was good and being repaired. 75 Micron just is not enough hard vacuum to dry out a system that has been open for very long.
>
> Try the local pawn shops first. The vacuum pump is something that people let go of easily.
>
> Try for a 2 stage (~10 micron) and you won't regret the extra expense.
>
> Matt - You don't want to know what I use.

Yep, so far that is all we have used it for. Horrible freight has a 2 stage available now as well, I don't know anything about it.

I also used our pump to pull the air out of some molding silicone but it didn't seem to have the power to completely evacuate the air backing up what Matt said.

--
Brian & RaeDean

1973 26' #383

Washougal WA

[Matt Colie]

chasingsummer wrote on Sat, 17 August 2013 16:39

> is the compressor in my old ac/dc fridge any good for this?

Not very likely. That pump is such amazing small capacity, that while if it is on good condition, it would suffice, it might just take days.

I suggest that if you have a working AC/DC reefer, you offer it for sale to someone interested. That should buy you a decent vacuum pump.

Matt

--
Matt & Mary Colie
'73 Glacier 23 Chaumière (say show-me-air)
Now with 4 working Rear Brakes
SE Michigan - Twixt A2 and Detroit

[Matt Colie]

larry.whisler wrote on Sat, 17 August 2013 17:34

> Has anyone used the compressor out of a working roof a/c unit for this?
>
> larry

Larry,

I very much doubt that a roof units pump would do a very good job. They are just all wrong. LOTS of ways. If you want more anwer, wait until I am awake.

Good Night

Matt


--
Matt & Mary Colie
'73 Glacier 23 Chaumière (say show-me-air)
Now with 4 working Rear Brakes
SE Michigan - Twixt A2 and Detroit