Home » Public Forums » GMCnet » Evaporator Removal, Other A/C Questions (AC Revival)
| Evaporator Removal, Other A/C Questions [message #132163] |
Sun, 26 June 2011 23:40  |
jcurran
Messages: 52
Registered: May 2009
Karma: 0
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Hi Folks,
A few pieces are missing from my dash air system and I am going to try to rebuild it. I have lots of questions but here are three pressing ones:
Can anyone tell me how many screws are holding the condenser in the A/C housing ? I have removed 4 from the top yet it still won't budge. There is some pretty tough sealant involved, though.
I have a 76 Palm Beach. Looking at the parts book, Figure 26.025 it seems to show the dryer directly attached to the condenser. But there is talk of a "short hose" on the forum and mention of two hoses in the last page of the A/C section in the parts book. Can someone explain ?
Finally, where exactly does the vacuum feeding the A/C vacuum tank come from? The supply line is missing on my system.
Thanks in advance,
Jim
Jim Curran
1976 Palm Beach
Alexandria, OH
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| Re: Evaporator Removal, Other A/C Questions [message #132168 is a reply to message #132163] |
Mon, 27 June 2011 00:26  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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The is a hose runs from that tank to the top of the engine for vacuum. Be careful running a new hose if you have not blocked the crossovers on your manifold. If you let the hose lay on top of the crossovers it will melt. You could make yourself a tee and connect it into the brake line vacuum hose which is nearby. On mine I also have a vacuum boost pump so I connected my tee in the line between the vacuum pump and the brake booster. The reduces the tendency for the vacuum operated doors to move under heavy acceleration which is a low vacuum condition.
You have several options so just choose a vacuum source that is convenient to you.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Evaporator Removal, Other A/C Questions [message #132200 is a reply to message #132163] |
Mon, 27 June 2011 07:44 |
fred v
Messages: 999
Registered: April 2006
Location: pensacola, fl.
Karma: 0
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| jcurran wrote on Sun, 26 June 2011 23:40 |
Hi Folks,
A few pieces are missing from my dash air system and I am going to try to rebuild it. I have lots of questions but here are three pressing ones:
Can anyone tell me how many screws are holding the condenser in the A/C housing ? I have removed 4 from the top yet it still won't budge. There is some pretty tough sealant involved, though.
I have a 76 Palm Beach. Looking at the parts book, Figure 26.025 it seems to show the dryer directly attached to the condenser. But there is talk of a "short hose" on the forum and mention of two hoses in the last page of the A/C section in the parts book. Can someone explain ?
Finally, where exactly does the vacuum feeding the A/C vacuum tank come from? The supply line is missing on my system.
Thanks in advance,
Jim
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i assume you mean the evaporator. i pulled mine out for cleaning and it was hard to get it out. it is a very close fit in the HVAC box top and bottom. try carefully to get a putty knife under it to break it loose from the sticky stuff.
Fred V
'77 Royale RB 455
P'cola, Fl
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| Re: [GMCnet] Evaporator Removal, Other A/C Questions [message #132202 is a reply to message #132200] |
Mon, 27 June 2011 08:00 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Senior Member |
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It makes a difference. Put a set of 135 volt MOVs across ech hot feed to ground and a couple turns in the power cord, and you'll keep the smoke inside the TV set and the inverters. MOVs take a small amount of time to clamp, and the added inductance will intergarte the leading edge of the lightning pulse a bit (slow its rise time) enough to keeop the peak voltage which appears in the coach substantially lower. When you find tidbits of the MOVs and blast marks in their box, they have dione their job.
--johnny
--- On Mon, 6/27/11, fred veenschoten <fredntoni@cox.net> wrote:
From: fred veenschoten <fredntoni@cox.net>
Subject: Re: [GMCnet] Evaporator Removal, Other A/C Questions
To: gmclist@temp.gmcnet.org
Date: Monday, June 27, 2011, 12:44 PM
jcurran wrote on Sun, 26 June 2011 23:40
> Hi Folks,
>
> A few pieces are missing from my dash air system and I am going to try to rebuild it. I have lots of questions but here are three pressing ones:
>
> Can anyone tell me how many screws are holding the condenser in the A/C housing ? I have removed 4 from the top yet it still won't budge. There is some pretty tough sealant involved, though.
>
> I have a 76 Palm Beach. Looking at the parts book, Figure 26.025 it seems to show the dryer directly attached to the condenser. But there is talk of a "short hose" on the forum and mention of two hoses in the last page of the A/C section in the parts book. Can someone explain ?
>
> Finally, where exactly does the vacuum feeding the A/C vacuum tank come from? The supply line is missing on my system.
>
> Thanks in advance,
>
> Jim
i assume you mean the evaporator. i pulled mine out for cleaning and it was hard to get it out. it is a very close fit in the HVAC box top and bottom. try carefully to get a putty knife under it to break it loose from the sticky stuff.
--
Fred V
'77 Royale RB 455
P'cola, Fl
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Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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| Re: Evaporator Removal, Other A/C Questions [message #132248 is a reply to message #132163] |
Mon, 27 June 2011 11:38 |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
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| jcurran wrote on Sun, 26 June 2011 21:40 |
Hi Folks,
A few pieces are missing from my dash air system and I am going to try to rebuild it. I have lots of questions but here are three pressing ones:
Can anyone tell me how many screws are holding the condenser in the A/C housing ? I have removed 4 from the top yet it still won't budge. There is some pretty tough sealant involved, though.
I have a 76 Palm Beach. Looking at the parts book, Figure 26.025 it seems to show the dryer directly attached to the condenser. But there is talk of a "short hose" on the forum and mention of two hoses in the last page of the A/C section in the parts book. Can someone explain ?
Finally, where exactly does the vacuum feeding the A/C vacuum tank come from? The supply line is missing on my system.
Thanks in advance,
Jim
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I don't know if it will help, but here are my photos of my evaporator cleaning and repair adventure.
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4048
Rob Allen
former owner of '76 x-PB
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| Slow [message #132308 is a reply to message #132248] |
Mon, 27 June 2011 16:16 |
bukzin
Messages: 840
Registered: April 2004
Location: North California
Karma: 0
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Senior Member |
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This part of your job is slow going.
We spent a few days just getting all of this apart.
Budget enough time, and band-aids.
Bukzin
1977 Palm Beach
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| Re: [GMCnet] Evaporator Removal, Other A/C Questions [message #132445 is a reply to message #132405] |
Tue, 28 June 2011 10:42 |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
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| ljdavick wrote on Mon, 27 June 2011 22:31 |
Rob,
How is that fix holding up now that you've removed all that disgusting gunk and re-sealed the doors?
Larry Davick
The Mystery Machine
On Jun 27, 2011, at 9:38 AM, Rob Allen wrote:
> I don't know if it will help, but here are my photos of my evaporator cleaning and repair adventure.
>
> http://www.gmcmhphotos.com/photos/showgallery.php?cat=4048
>
> --
> Rob Allen
> former owner of '76 x-PB
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I sold my GMC to Mitch in Tacoma a couple of years ago. I recharged it with R12a just prior to selling, and have not heard that there has been any problems. I was never really satisfied with the dash AC, but that is a common problem up to 1977's. I will continue to contend that the evaporator is just too small for the job. GM Harrison AC units of that era were generally great, but somehow the GMC Motorhome got left out. They gave the design job to some kid fresh out of engineering school, and forgot to check on him as the senior designers were on summer vacation trips. At least that is my speculation.
Rob Allen
former owner of '76 x-PB
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| Re: [GMCnet] Evaporator Removal, Other A/C Questions [message #132449 is a reply to message #132405] |
Tue, 28 June 2011 11:04 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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Larry if you haven't done the return air & O.S.A. block modification to your 76 yet I would suggest you put it on your to do list. It doubled the supply air in my 76. I made the return hole even bigger then Zay suggested to be sure I got the maximum benefit.
Roy
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: [GMCnet] Evaporator Removal, Other A/C Questions [message #132563 is a reply to message #132449] |
Wed, 29 June 2011 01:40 |
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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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Roy,
I have Zay's article printed out and dog-eared by now. This is high on my list, but I want to make sure I've got the leak fixed first.
Larry Davick
The Mystery Machine
On Jun 28, 2011, at 9:04 AM, roy@gmcnet.org, keen@gmcnet.org, Minden@gmcnet.org, Nv '76 Glenbrook wrote:
>
>
> Larry if you haven't done the return air & O.S.A. block modification to your 76 yet I would suggest you put it on your to do list. It doubled the supply air in my 76. I made the return hole even bigger then Zay suggested to be sure I got the maximum benefit.
> Roy
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Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
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