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| air conditioning questions [message #134493] |
Wed, 13 July 2011 18:01  |
gmchunter
Messages: 222
Registered: March 2008
Location: ORANGE, CA
Karma: 0
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Senior Member |
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I seem to be confused because I don't have any knowledge of working on the air conditioning systems.
Like others I have spent money on new air conditioning compressor and dryer, charging up system with R12 and getting very little from it. In fact six months after the first charge I went back and spent more pulling a vacuum and adding more R12. Now six months later it appears I need another charge as it doesn't appear to be cooling properly--I am tired of paying $100 to $200 each visit.
What tools do I need to "pull a vacuum" on the system?
I see 2.5cfm vacuum pumps with R12 and R34 fittings available on ebay for $89 and gauges available from about $39. I was thinking of buying these tools to use but What happens to the R12 and oil in your system when you pull a vacuum with these tools and then add the R12A propane based coolant?
I am thinking that if I can get it to work decently with the R12a coolant it will only cost a minimum to add every six months if necessary. It seems the only saving grace of R12 is that you can get the professionals to work on it.
Any thoughts or suggestions?
Michael
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| Re: air conditioning questions [message #134498 is a reply to message #134493] |
Wed, 13 July 2011 18:57  |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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Michael
I think a good place to start would be to get someone you can trust to leak check it before you remove the R12. If the leak is small and you don't want to fix it at this time just add some Duracool to the system it won't hurt anything. The only problem would be you would have to release what is in the system before you could take it to a qualified repair shop as they most likely wouldn't want to mess with the duracool as they can't recover it. They would rather recover your R12 and sell it back to you.
Roy
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: [GMCnet] air conditioning questions [message #134506 is a reply to message #134493] |
Wed, 13 July 2011 19:17 |
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ljdavick
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
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Senior Member |
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Michael,
You are right where I was a few months ago. My coach happens to have the R-134 fittings (adapters?) installed as Tom Hampton at Grandview put them on to diagnose my system (I had him stop - too much $$ spent). The tools I used all relied on these newer fittings. I used the cheap Harbor Freight vacuum pump attached to the cheap Harbor Freight gauge set and pulled a vacuum for an hour or so. I had never done this before, but I did read and worry about it for some time before doing it, though it turned out to be so simple I felt foolish for waiting and worrying. The vacuum pump attaches to your shop air compressor, but be forewarned, it needs a lot of air. If your compressor is not up to the task, buy a better vacuum pump. The $150 pump from Harbor Freight would have been my second choice, though I never thought to look at renting one.
I believe that pulling a vacuum does not evacuate the oil from your system, just air and hopefully any water vapor. All you need to replace is the refrigerant. I did not have a can tap to attach to my gauge set, but I did have that dandy gauge that came with a bottle of R-134 from Harbor Freight, so I tapped a can of Duracool and attached it to the low pressure side (blue) of the A/C.
There is an electric switch that is part of the high pressure tubing that has 2 wires attached to it. Remove the connector from the switch and stick a wire or a paperclip into both wires to jumper the connection - this will turn on your A/C Clutch.
Let the engine run and pour in the Duracool to the blue low pressure side. I don't remember why, but I held the can upside-down and tried my best to warm it between my hands while I pulled the trigger to shoot the juice. I think this made me look more professional. If someone can keep the engine at 1,500 rpm while you are emptying the 3rd can look at the gauge to make sure you have about 20 lbs of pressure here. More is not better, less is not better. My A/C runs pretty cold now, but then we've still got winter in California <sigh>.
This is just what my simple mind retained. Duracool is under $10 a can, so for about $100 you could be a shadetree mechanic and have the same A/C results as your $400 professional. There is even the possibility that this will be a better fix, as the pressure is lower throughout, and therefore less likely to leak.
Good luck and please keep us updated!
Larry Davick
Fremont, California
The Mystery Machine
'76 (ish) Palm Beach
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Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
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| Re: [GMCnet] air conditioning questions [message #134522 is a reply to message #134513] |
Wed, 13 July 2011 21:21 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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Back in the days of Route 66, (I know, I'm dating myself) there used to be a
Major Chain gas stations who employed what was known as 50 %ers. They would
use fern picking rings, which were a finger ring with a hooked cutter on it,
to place cuts on fan belts and hoses and then "warn" the unsuspecting driver
of belts or hoses about to fail. They would also use ice picks on the tires,
and "short stick" the oil dipsticks. They received 50 % of the sales from
such tricks. There was a lot of people that fell victim to these jerks.
Every repair business looks bad with characters like that out there. I see
that AC shops are not immune from those antics either. Buyer beware is the
best policy if you don't know the shop.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Wed, Jul 13, 2011 at 6:28 PM, Emery Stora <emerystora@mac.com> wrote:
>
> On Jul 13, 2011, at 5:01 PM, MICHAEL FOSTER wrote:
>
> >
> >
> > I am thinking that if I can get it to work decently with the R12a coolant
> it will only cost a minimum to add every six months if necessary. It seems
> the only saving grace of R12 is that you can get the professionals to work
> on it.
> >
> > Any thoughts or suggestions?
> >
> > Michael
> >
> >
>
> So, you think that getting professionals to work on it is a "saving
> grace"???
>
> Let me tell you an experience I had last month.
>
> I was up in Colorado with a car that still had R134a in it. The air
> conditioner stopped working and it was 95 deg outside. We had to drive 450
> miles back home in that hot weather.
> A quick look told me that is was probably electrical but I didn't have any
> tools with me.
>
> I saw a sign at an AMMCO transmission shop that said "FREE AIRCONDITIONING
> CHECK".
>
> I stopped there and talked to the fellow at the desk telling him that I
> would like my system checked and that I thought it was an electrical
> problem.
> He took the car to the shop but told me that I had to wait in the waiting
> room.
> About 20 minutes later he told me that the technician had checked it and
> that it definitely was low on charge and would have to be evacuated, leak
> checked and refilled.
> I asked him what the charge would be and he told me "about $400".
>
> I told him that I would have to think about it (yeah! -- about 2 seconds!)
> and I left.
> We drove home in the heat without air conditioning and the day after we got
> home I put my gauges on it and the pressure looked find without it running.
> I hot wired my clutch and immediately got good cooling from the vents. I
> checked the gauges and they were just right for a fully charged system.
>
> Further checking showed that I had a bad switch on the dash that turns on
> the air conditioner clutch. The blower worked just fine and the light from
> the switch would come on but no power to the air conditioning clutch. $15
> in parts later and doing it myself has my air conditioner working just fine.
>
> So much for the "saving grace" of a professional. I hate to say this but
> with this and my experience in the past, I think that at least half of the
> professional air conditioning shops are crooks.
>
> My suggestion is that GMCers learn how to work on the system themselves and
> save themselves a lot of time and money.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM
>
>
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| Re: [GMCnet] air conditioning questions [message #134524 is a reply to message #134522] |
Wed, 13 July 2011 21:27 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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Jim,
Reminds me of when my Dad came to visit me in Houston in the 1970's. He had
a tire fail on the way and was forced to buy a new set at an outrageous
price from a major gas stating chain. When he got home to California he
wrote to the chain laying out the situation and they noted that he had been
overcharged by the station and was refunded a fair amount of money.
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of James Hupy
Sent: Thursday, 14 July 2011 12:21 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] air conditioning questions
Back in the days of Route 66, (I know, I'm dating myself) there used to be a
Major Chain gas stations who employed what was known as 50 %ers. They would
use fern picking rings, which were a finger ring with a hooked cutter on it,
to place cuts on fan belts and hoses and then "warn" the unsuspecting driver
of belts or hoses about to fail. They would also use ice picks on the tires,
and "short stick" the oil dipsticks. They received 50 % of the sales from
such tricks. There was a lot of people that fell victim to these jerks.
Every repair business looks bad with characters like that out there. I see
that AC shops are not immune from those antics either. Buyer beware is the
best policy if you don't know the shop.
Jim Hupy
Salem, OR
78 GMC Royale 403
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Unsubscribe or Change List Options:
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: [GMCnet] air conditioning questions [message #134537 is a reply to message #134513] |
Wed, 13 July 2011 22:44 |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
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Senior Member |
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| emerystora wrote on Wed, 13 July 2011 18:28 |
On Jul 13, 2011, at 5:01 PM, MICHAEL FOSTER wrote:
>
>
> I am thinking that if I can get it to work decently with the R12a coolant it will only cost a minimum to add every six months if necessary. It seems the only saving grace of R12 is that you can get the professionals to work on it.
>
> Any thoughts or suggestions?
>
> Michael
>
>
So, you think that getting professionals to work on it is a "saving grace"???
Let me tell you an experience I had last month.
(snip)
So much for the "saving grace" of a professional. I hate to say this but with this and my experience in the past, I think that at least half of the professional air conditioning shops are crooks.
My suggestion is that GMCers learn how to work on the system themselves and save themselves a lot of time and money.
Emery Stora
77 Kingsley
Santa Fe, NM
|
It even happens at the new car dealer level. I purchased a new Toyota Camry Hybrid and the all electric AC was dead on arrival when I left the dealership. Brought it back the next day and they found it had no refrigerant. (from the factory) They recharged it. Worked for a while. Then no AC again. I took it in and they said "nothing wrong with it, and we checked the charge and it is right where it should be" Was a cool day. Next day it was hot hot hot, and no AC. I was hot under the collar and brought it back, demanded to have the service manager come out and tell me the AC was working right. Of course, with 70 degree air blowing out the vents, and the thing on Max, and hot as hell in the car they agreed something was wrong. They gave me a loaner car. The next day they called and said it was fixed. It needed a new electric compressor which was leaking the refrigerant. Now, this was all done under warrantee so my cost was my time and being PO'ed at them.
What really upset me was their telling me two days previously that the AC was fine, and they had checked the refrigerant level and it was ok. Then when it was hot, suddenly the refrigerant was gone... hmmm, how about that?
They may not be crooks, but they sure were stupid. Had it not been under warrantee, who knows what they would have charged to fix it.
Rob Allen
former owner of '76 x-PB
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| Re: air conditioning questions [message #134598 is a reply to message #134549] |
Thu, 14 July 2011 14:31 |
stick miller
Messages: 1036
Registered: March 2010
Location: Americus, Georgia
Karma: 0
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Senior Member |
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Let me throw in my 2 cents worth. Several months ago the A/C on my '96 Cadillac was failing. Ken H. offered to help me out. I asked that he use his last 2 cans of 134 since I wanted to make sure I could go back to my mechanic if I needed to. Silly me!
Without any obvious leaks, the 134 lasted about a month. We recharged with Duracool and it is icy cold even in the heat and humidity of SW Georgia.
Not sure why the 134 leaked out and the Duracool doesn't but I'm a believer.
Stick Miller
'78 Royale - "White Trash" - she left me for another man
'76 Eleganza - "Cousin Eddie" Sold
'84 Bluebird Wanderlodge - "Past Tents"
Americus, GA
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