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Heater Box Debris [message #172707] Sat, 09 June 2012 14:21 Go to next message
JShot is currently offline  JShot   United States
Messages: 485
Registered: October 2006
Location: NW Ohio
Karma: 0
Senior Member
I know you've seen this problem before- I saw the previous photos on the photo site last week, and thought I'd check out our system today. I really wasn't expecting this - I thought it would be clean and ok. Wrong!
This is where I stopped after a few minutes, and took the pics. With a mirror, I can see that the whole box bottom half is full of this stuff. The three fan speed resistors (ours is a '78) were packed with the straw (I said it's hay, SHE said it's straw).
So, my question - I want to take this box apart. I know I can probably clean it out with a vac through the hole, but I'd rather do it right. The heater core is probably packed solid. Are there any step by step instructions, or tips on the dis-assembly of this heater box?
I know, I haven't checked the manuals, or Gene's site, or called Ken H for help. Anyway, this might be a good refresher course for some of the 'newbies' that hadn't thought about this yet. As always, any help is always appreciated!

http://www.gmcmhphotos.com/photos/g6100-heater-box-debris.html

Shot



John Shotwell
Ridgeville Corners, OH
78 Royale Center Kitchen
Re: Heater Box Debris [message #172708 is a reply to message #172707] Sat, 09 June 2012 14:44 Go to previous messageGo to next message
C Boyd is currently offline  C Boyd   United States
Messages: 2629
Registered: April 2006
Karma: 18
Senior Member
Hi Shot. Yep wear gloves, there is a thousand sharp little places in removing the front cover. Just take all the little screws out and carefully pry the front cover off. I`m thinkin they probably got in thru the vents??







JShot wrote on Sat, 09 June 2012 15:21

I know you've seen this problem before- I saw the previous photos on the photo site last week, and thought I'd check out our system today. I really wasn't expecting this - I thought it would be clean and ok. Wrong!
This is where I stopped after a few minutes, and took the pics. With a mirror, I can see that the whole box bottom half is full of this stuff. The three fan speed resistors (ours is a '78) were packed with the straw (I said it's hay, SHE said it's straw).
So, my question - I want to take this box apart. I know I can probably clean it out with a vac through the hole, but I'd rather do it right. The heater core is probably packed solid. Are there any step by step instructions, or tips on the dis-assembly of this heater box?
I know, I haven't checked the manuals, or Gene's site, or called Ken H for help. Anyway, this might be a good refresher course for some of the 'newbies' that hadn't thought about this yet. As always, any help is always appreciated!

http://www.gmcmhphotos.com/photos/g6100-heater-box-debris.html

Shot





C. Boyd
76 Crestmont
East Tennessee
Re: Heater Box Debris [message #172709 is a reply to message #172707] Sat, 09 June 2012 14:49 Go to previous messageGo to next message
Pryzl1 is currently offline  Pryzl1   United States
Messages: 100
Registered: November 2011
Location: Toledo, OH
Karma: 0
Senior Member
If you would like some help, give me a call. I've got a great deal to learn.

John 1976 GMC Eleganza II - "The Never Ending Story" Partial Restoration - a work in progress 455cc NW Ohio Member of the GMCMI, GMC Great Lakers Motorhome Club, GMCES and Dixielanders
Re: Heater Box Debris [message #172710 is a reply to message #172707] Sat, 09 June 2012 14:58 Go to previous messageGo to next message
John Heslinga   Canada
Messages: 632
Registered: February 2011
Location: Edmonton, Alberta, Canada
Karma: 4
Senior Member
John:

On my 74. I did he following to clean out that area .
It allowed me to also make some rubber gasget/seal repairs that I found I needed to improve air flow and cooling. I'll post some pictures later.

Remove:
Radiator over flow bottle
Windshield washer bottle
Front cover
Bottom cover
Clean out stuff.from behind the evaporator
Check heater core with mirror best you can
Repair rubber seals
Replace parts
Replace any caulking


I would have liked to do more service on mine but that would have needed entire box out


Best regards
John H


John and Cathie Heslinga 1974 Canyonlands 260 455, Manny tranny and 1 ton, 3:70 LS, Red Seal Journeyman, DTE, BEd. MEd. Edmonton, Alberta
Re: [GMCnet] Heater Box Debris [message #172734 is a reply to message #172707] Sat, 09 June 2012 19:18 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
John,

Man are you lucky!

One of the things that was noted when brainstormed here and put together the
Fire Prevention Guide was that the resistor network could start a fire in
the heater if it was full of critter crap and from the pictures you've
supplied you got a serious case of it!

If you go to MM X-7725 page 1B-13 you'll find Figure 14 - Evaporator and
Heater Housing Components - Typical. On one of my visits to the COOP we
removed the FACE PANEL and bottom cover to check for critter crap in Double
Trouble.

Looking at the exploded view I note two things: 1) on Double Trouble there
was a steel doubler strip under the bottom cover on the outside directly
under where the evaporator came into contact with the bottom cover. 2) there
were two "sticky strips" on the inside of the bottom cover located directly
under the bottom of the evaporator at the front and rear.

When we reassembled the housing I bent the doubler slightly forming it into
an upside down "U" so it would push up on the middle of the evaporator and
we replaced the "sticky strips." I don't remember what we used.

Regards,
Rob M.

-----Original Message-----
From: Shotwell

I know you've seen this problem before- I saw the previous photos on the
photo site last week, and thought I'd check out our system today. I really
wasn't expecting this - I thought it would be clean and ok. Wrong!
This is where I stopped after a few minutes, and took the pics. With a
mirror, I can see that the whole box bottom half is full of this stuff. The
three fan speed resistors (ours is a '78) were packed with the straw (I said
it's hay, SHE said it's straw).

So, my question - I want to take this box apart. I know I can probably clean
it out with a vac through the hole, but I'd rather do it right. The heater
core is probably packed solid. Are there any step by step instructions, or
tips on the dis-assembly of this heater box?
I know, I haven't checked the manuals, or Gene's site, or called Ken H for
help. Anyway, this might be a good refresher course for some of the
'newbies' that hadn't thought about this yet. As always, any help is always
appreciated!

http://www.gmcmhphotos.com/photos/g6100-heater-box-debris.html

Shot


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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
Re: Heater Box Debris [message #172740 is a reply to message #172707] Sat, 09 June 2012 20:00 Go to previous messageGo to next message
Dennis S is currently offline  Dennis S   United States
Messages: 3046
Registered: November 2005
Karma: 2
Senior Member
Shot,

There is this photo album by idrob...

he does more than you may be planning but it has good photos.

http://www.gmcmhphotos.com/photos/g4048-dash-ac-cleaning-and-repair.html

In my experience, once you remove all the fasteners you will think it is still attached -- the duct sealer is very strong and you may have to work in from an edge with a putty knife.

Dennis

JShot wrote on Sat, 09 June 2012 14:21

I know you've seen this problem before- I saw the previous photos on the photo site last week, and thought I'd check out our system today. I really wasn't expecting this - I thought it would be clean and ok. Wrong!
This is where I stopped after a few minutes, and took the pics. With a mirror, I can see that the whole box bottom half is full of this stuff. The three fan speed resistors (ours is a '78) were packed with the straw (I said it's hay, SHE said it's straw).
So, my question - I want to take this box apart. I know I can probably clean it out with a vac through the hole, but I'd rather do it right. The heater core is probably packed solid. Are there any step by step instructions, or tips on the dis-assembly of this heater box?
I know, I haven't checked the manuals, or Gene's site, or called Ken H for help. Anyway, this might be a good refresher course for some of the 'newbies' that hadn't thought about this yet. As always, any help is always appreciated!

http://www.gmcmhphotos.com/photos/g6100-heater-box-debris.html

Shot





Dennis S
73 Painted Desert 230
Memphis TN Metro
Re: Heater Box Debris [message #172742 is a reply to message #172707] Sat, 09 June 2012 20:26 Go to previous messageGo to next message
JShot is currently offline  JShot   United States
Messages: 485
Registered: October 2006
Location: NW Ohio
Karma: 0
Senior Member
Charlie - I got the front cover off. The two cores look very clean from the front. Beats me how that stuff gets in behind there...

John H - I had to remove all that you noted. I didn't realize the bottom would come off, but it did.

Rob - Yes, the doubler was there, and slightly bent DOWN in the middle. If the holes are centered, I'll just replace it with the crown up - good advice! And it looks like there is/was a foam strip all around the circumference of the evaporator on the inside of that bottom cover. Now all I have to do is find replacement foam for the doors, etc - boy, that old foam stuff is nasty!

Dennis - thanks for the link. I have seen those before, but couldn't find them today. The ones I saw this week were of the resistors removed, and looking like what I found today. I really hate to tear into it any more, but I know I should as long as I'm this far. Now that the bottom is off, I'll look tomorrow with a mirror at the back side of the evap and see what's there. Because I posted a few days ago about the a/c system cycling on and off every 20 seconds (low on Duracool), maybe it's just a good time to look at it all and replace the things idrob did.

Thanks for all the comments and advice

Shot



John Shotwell
Ridgeville Corners, OH
78 Royale Center Kitchen
Re: [GMCnet] Heater Box Debris [message #172750 is a reply to message #172742] Sat, 09 June 2012 20:53 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
John,

Don't stop now. You can only get to the aft side of the evaporator and
truly clean it by removing the evaporator. It will probably be firmly
"glued" to the panel at the top and require a putty knife, possibly aided
with a heat gun, to break it loose. Then you can pivot it left toward the
hoses so you can clean it.

I don't recall whether your '78 has an outside air opening; if it does,
consider putting <1/2" hardware cloth over it to keep critters out in the
future. If you had a 75'/'76 I'd say close it completely and implement the
recirculate-only mods. With that port closed, any future visitors will
have to enter through the cockpit -- if you really want to make them
unwelcome, you could cover the openings through the firewall while you've
got it all apart.

Or you could just do this:
http://www.gmcmhphotos.com/photos/g5280-dash-air-conditioning-redesign.html
or
http://goo.gl/iEmh4

:-)

Ken H.



On Sat, Jun 9, 2012 at 9:26 PM, John Shotwell wrote:

>
>
> Charlie - I got the front cover off. The two cores look very clean from
> the front. Beats me how that stuff gets in behind there...
>
> John H - I had to remove all that you noted. I didn't realize the bottom
> would come off, but it did.
>
> Rob - Yes, the doubler was there, and slightly bent DOWN in the middle. If
> the holes are centered, I'll just replace it with the crown up - good
> advice! And it looks like there is/was a foam strip all around the
> circumference of the evaporator on the inside of that bottom cover. Now all
> I have to do is find replacement foam for the doors, etc - boy, that old
> foam stuff is nasty!
>
> Dennis - thanks for the link. I have seen those before, but couldn't find
> them today. The ones I saw this week were of the resistors removed, and
> looking like what I found today. I really hate to tear into it any more,
> but I know I should as long as I'm this far. Now that the bottom is off,
> I'll look tomorrow with a mirror at the back side of the evap and see
> what's there. Because I posted a few days ago about the a/c system cycling
> on and off every 20 seconds (low on Duracool), maybe it's just a good time
> to look at it all and replace the things idrob did.
>
> Thanks for all the comments and advice
>
> Shot
>
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] Heater Box Debris [message #172751 is a reply to message #172742] Sat, 09 June 2012 20:58 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
John,

I reckon the critters carry it in through the A/C outlets and wind up making
their nests there.

Re the foam - IIRC JimB had some thin white colored Styrofoam sheet that was
used to package parts.

Going through the system end to end sounds like a damn good idea to me!
Hopefully you will be good to go for the whole summer!

Regards,
Rob M.

-----Original Message-----
From: John Shotwell

Charlie - I got the front cover off. The two cores look very clean from the
front. Beats me how that stuff gets in behind there...

John H - I had to remove all that you noted. I didn't realize the bottom
would come off, but it did.

Rob - Yes, the doubler was there, and slightly bent DOWN in the middle. If
the holes are centered, I'll just replace it with the crown up - good
advice! And it looks like there is/was a foam strip all around the
circumference of the evaporator on the inside of that bottom cover. Now all
I have to do is find replacement foam for the doors, etc - boy, that old
foam stuff is nasty!

Dennis - thanks for the link. I have seen those before, but couldn't find
them today. The ones I saw this week were of the resistors removed, and
looking like what I found today. I really hate to tear into it any more, but
I know I should as long as I'm this far. Now that the bottom is off, I'll
look tomorrow with a mirror at the back side of the evap and see what's
there. Because I posted a few days ago about the a/c system cycling on and
off every 20 seconds (low on Duracool), maybe it's just a good time to look
at it all and replace the things idrob did.

Thanks for all the comments and advice

Shot


--
John Shotwell
Ridgeville Corners, OH
78 Royale Center Kitchen
Web Site: GMCmhRegistry.com /
Email: john@gmcmhregistry.com
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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
Re: [GMCnet] Heater Box Debris [message #172758 is a reply to message #172750] Sat, 09 June 2012 21:55 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
John,

I meant to mention: The best thing I've found to pad the A/C doors is
pickup truck camper shell sealer. I found some that's about 1/4" thick
soft closed-cell foam with adhesive on one side and plastic, possibly
Mylar, on the other. It's about 1-1/2" wide, so a couple of strips
completely covers a door. The plastic keeps the door from sticking.

Ken H.
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] Heater Box Debris [message #172765 is a reply to message #172758] Sun, 10 June 2012 00:51 Go to previous message
sgltrac is currently offline  sgltrac   United States
Messages: 2797
Registered: April 2011
Karma: 1
Senior Member
That is the same stuff I used in the heater box on the Pig Ken

Sully
77 royale

Sent from my iPhone

On Jun 9, 2012, at 7:55 PM, Ken Henderson <hend4800@bellsouth.net> wrote:

> John,
>
> I meant to mention: The best thing I've found to pad the A/C doors is
> pickup truck camper shell sealer. I found some that's about 1/4" thick
> soft closed-cell foam with adhesive on one side and plastic, possibly
> Mylar, on the other. It's about 1-1/2" wide, so a couple of strips
> completely covers a door. The plastic keeps the door from sticking.
>
> Ken H.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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Sully 77 Royale basket case. Future motorhome land speed record holder(bucket list) Seattle, Wa.
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