Author Topic: 4905 air conditioner  (Read 12389 times)

larryh

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4905 air conditioner
« on: June 26, 2006, 08:23:55 AM »
On my bus everything works but needs a charge and can find nobody to service R22 refrigerant. Has anybody converted over to 134A their self.?

Do I have to charge compressor seperate from condenser and do I need two kits to do it?

Any input will be appreciated?

Larry Higuera

Offline TomC

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Re: 4905 air conditioner
« Reply #1 on: June 26, 2006, 08:44:52 AM »
Usually the change over will involve completely evacuating the system, changing the reciever dryer and the oil in the compressor to 134A compatable.  Rinse the system with Nitrogen, and also change the charging ports to the 134A type.  Shouldn't be a problem since R22 is rather corrosive as compared to 134A (R22 requires you use copper tubing compared to 134a that uses regular neoprene type hoses).  Maybe Nick will chime in here.  Good Luck, TomC
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Offline roadrunnertex

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Re: 4905 air conditioner
« Reply #2 on: June 26, 2006, 10:24:49 AM »
R-22 is (NOT) interchanglable with R134.
R-22 will out cool any R-134 system that was converted.
Different system pressures with R-22/R-134.The suction and discharge pressures are higher with R-22.
R-22 should be easy to find a few years ago I bought a 30 pound cylinder of R-22 at Sam's.
jlv

 


Ncbob

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Re: 4905 air conditioner
« Reply #3 on: June 26, 2006, 01:01:21 PM »
Nothing current on the R-22?  I need some to charge the A/C in my boat.  Nick....Help??????

Offline roadrunnertex

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Re: 4905 air conditioner
« Reply #4 on: June 27, 2006, 06:16:08 AM »

The P8M4905A GMC Coaches( HAVE) R-22 installed from the factory.
If you read the GM P8M4905A maintenance manual it states this as a fact.
jlv

Offline roadrunnertex

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Re: 4905 air conditioner
« Reply #5 on: June 27, 2006, 06:43:42 AM »
System capacity aprox. 60 pounds R-22.
jlv

Offline Buffalo SpaceShip

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Re: 4905 air conditioner
« Reply #6 on: June 27, 2006, 09:42:26 AM »
Larry,
I'd keep it R-22, for sure. From the prices I've seen by Google-ing for refrigerants, R-134A is almost twice the cost. AFAIK, R-22 has not been phased-out the way R-12 has, so it's still affordable, and superior to R-134A.

The biggest question is whether to keep your coach air system maintained or just pull it all out. From Da Books, it seems the biggest sections of maint. are always the coach A/C systems. And yours was designed to keep 49 passengers chilled in a leaky, multi-window bus... not an insulated, skinned-over coach (if that's what yours is). So the compressor will likely cycle on and off quite a bit in RV service... or freeze you out of the bus. 60# of R-22 will set you back a few hundred $ and chasing down those leaks, winterizing, testing, and keeping all 60# of that precious fluid from leaking out will be an ongoing part of your PM.

Plus, as you know, the coach air can only be used when rolling down the highway and not when parked. And the compressor and condensor compartments are great places to put stuff like batteries and gensets. Some busnuts use the term "free A/C" or "if it ain't broke don't trash it" as justifications for keeping the coach A/C intact... but the former is never the case (those compressors rob some serious HP) and the latter seldom is... like in your case. The only way they don't "get broke" is to "keep fixin' em".

Anyways, I'm not trying to throw rocks or anything, just giving some food for thought. Please keep us posted on your system and its progress.

Brian Brown
4108-216

Brian Brown
4108-216 w/ V730
Longmont, CO

larryh

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Re: 4905 air conditioner
« Reply #7 on: June 27, 2006, 10:17:14 AM »
Brian

No insult taken just your two cents worth and a honest opinion. This bus was a trailways bus originally and has been owned by two church groups and kept CA. Hiway Patrol inspected each yr.
The owner told me they had to have it charged each summer and tuned up but that everything was operational as far as he knew. My decision is to keep it and get to know something else for yearly maintenance. Or to change out now. I'm in the process of stripping it out now and getting ready to convert. My plans are to keep the original windows as much as possible no plans to raise roof etc. I want to keep the Buffalo appearance as much as possible outside . now the inside will be a different story. I am a diesel mechanic of 47+ yrs so maintenance is a piece of cake for me. and I'm more than willing to help others on this group.

Larry Higuera

Offline Buffalo SpaceShip

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Re: 4905 air conditioner
« Reply #8 on: June 27, 2006, 10:32:28 AM »
Larry, your knowlege and experience will be a great asset to this board and its users!

I LOVE the Buffs... esp. the stock ones with the humps. Mine was capped front and back before I got it, so I'm stuck with the "Space Ship" look.

Please keep us posted on your progress. And take lots of pics. And as you get to know your coach A/C system and its workings, you'll be a great help to those that choose to keep their systems intact.

Thanks,
Brian
Brian Brown
4108-216 w/ V730
Longmont, CO

Offline DavidInWilmNC

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Re: 4905 air conditioner
« Reply #9 on: June 27, 2006, 10:52:59 AM »
  .

Offline Nick Badame Refrig/ACC

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Re: 4905 air conditioner
« Reply #10 on: June 27, 2006, 10:59:31 AM »
Guy's

I modified some postings here!  This subject was getting out of hand. When it does, I will delete!!!!

Nick Badame
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Offline DavidInWilmNC

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Re: 4905 air conditioner
« Reply #11 on: June 27, 2006, 11:08:13 AM »
On my bus everything works but needs a charge and can find nobody to service R22 refrigerant. Has anybody converted over to 134A their self.?

Do I have to charge compressor seperate from condenser and do I need two kits to do it?

Any input will be appreciated?

Larry Higuera
Larry, you DID say any input would be appreciated.  Christy (and her husband Larry) own a heating and air business and are generally very helpful.  I don't know much about servicing bus A/C units, and I didn't get the idea that you did either.  Questions like "Do I have to charge compressor seperate from condenser and do I need two kits to do it?" don't really indicate a knowledge of these systems.  Her post was meant to keep from causing problems or hurting yourself, not as an insult.  She indicates this in the last line of her poste "Please do not be offended as this post, as is not intended to denigrate you,   it is merely meant to save you from hurting yourself or your a/c system."

I ask a lot of questions on this and the BNO board.  I sometimes get answers that I don't agree with.  I do try to respond politely to those that bother to post.  When people take time out of their day to try and help me, how can I be anything other than appreciative? 

David

Now this is silly.  It doesn't make a heck of a lot of sense for me to refer to two posts that are no longer available (have been deleted).  Although I understand we want this to be a friendly place, we are all adults and need to learn to get along in a civil fashion without posts being deleted.  I know that Christy didn't mean to sound bad in her post; I wonder if she'll take the time to post again, since hers, that contained a good bit of general info has been kicked to the curb (deleted).    >:(

Offline Nick Badame Refrig/ACC

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Re: 4905 air conditioner
« Reply #12 on: June 27, 2006, 11:21:11 AM »
David,

I'm sorry you feel that way, We certainly don't want anyone to feel uncomfortable here.

But, This board will not put up with any childish mud slinging!

My job is to keep this board clean and tasteful, And Thats What I Will Do!

If something is deleted here, it is first been discussed between Two Moderators before any action is taken.

Reguards
Nick-
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Offline Christyhicks

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Re: 4905 air conditioner
« Reply #13 on: June 27, 2006, 11:40:01 AM »
So, I guess I missed way out on something. . I thought someone was talking about their R-12 bus air system, converting it to R134.  If I sounded stupid or something, I apologize, but I guess I didn't realize that he was talking OTR air.  I sure did my best to be polite, just concerned if they were talking about rooftop a/c units or the OTR air that originally had 12. 

I didn't see any other posts, so I don't know what was said after mine, as I just now checked the site, so I just will assume that I must have insulted someone or said something someone took wrong.  If so, I apologize. 

Believe it or not, we run across quite a few people who think that R-22 and R-12 are the same thing and are interchangeable.  I personally know of someone who insisted that their home and truck used the same freon, going so far as to trying to put R-22 in it and destroying a compressor.  I realize now that being unfamiliar with new busses, I didn't realize that OTR a/c units had R-22 in, and if they did, why someone would choose to go to R134, which is again, why my brain was saying R-12. 

So, if I said something wrong, I apologize, but if someone doesn't mind, could you contact me privately, and let me know what all I said wrong, because I thought I was making it clear I meant no offense, and since I didn't see any of the other posts, I'm assuming I was the one who said something offensive.  I'd prefer not to let it happen again.  Christy Hicks
If chased by a bear, you don't need to run faster than the bear, just faster than your companion!

Offline DrivingMissLazy

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Re: 4905 air conditioner
« Reply #14 on: June 27, 2006, 12:09:35 PM »
Christy, in my opinion you did not say anything that was, or should have been, taken as offensive. Your post had a lot of good information in it which would be valuable to all the readers of the board. I know I learned something from it. Again, in my opinion, you have nothing to feel bad about or apoligize for. Keep up the great posts!

Richard

So, I guess I missed way out on something. . I thought someone was talking about their R-12 bus air system, converting it to R134.  If I sounded stupid or something, I apologize, but I guess I didn't realize that he was talking OTR air.  I sure did my best to be polite, just concerned if they were talking about rooftop a/c units or the OTR air that originally had 12. 

I didn't see any other posts, so I don't know what was said after mine, as I just now checked the site, so I just will assume that I must have insulted someone or said something someone took wrong.  If so, I apologize. 

Believe it or not, we run across quite a few people who think that R-22 and R-12 are the same thing and are interchangeable.  I personally know of someone who insisted that their home and truck used the same freon, going so far as to trying to put R-22 in it and destroying a compressor.  I realize now that being unfamiliar with new busses, I didn't realize that OTR a/c units had R-22 in, and if they did, why someone would choose to go to R134, which is again, why my brain was saying R-12. 

So, if I said something wrong, I apologize, but if someone doesn't mind, could you contact me privately, and let me know what all I said wrong, because I thought I was making it clear I meant no offense, and since I didn't see any of the other posts, I'm assuming I was the one who said something offensive.  I'd prefer not to let it happen again.  Christy Hicks
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body. But rather to skid in sideways, chocolate in one hand, a good Reisling in the other, body thoroughly used up, totally worn out and screaming:  WOO HOO, what a ride

 

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