Armstrong AC, how to recharge it

[Jim in Pima]

My 1975 Armstrong AC is giving up the ghost, last summer I would get
a faint odor of oil when it started, then by fall it was not cooling well
and locked up on start sometimes.
I really would like to keep it going, having seen the effort to replace it
I would like to get it recharged before the compressor is gone.
Can I ad R22 and oil and sealer to it by myself. Get a few more year
of service from it.? What equipment would I need. I live in a area where
it is doubtful I could find a professional to climb on the roof of the Airstream.
(my wife is not pleased about me doing it at 78)
Thanks

[TG Twinkie]

If you have a local heating and air conditioning shop. They may be willing to do the repairs. Not an RV shop. You would probably have to take the unit off of the trailer and take it to the shop.
It won't be a cheap fix. But from what I understand. If you can get it repaired (sounds like a new compressor is in order) it will be a better and more reliable unit than the new ones on the market today. After all look how long it has lasted.

[adonh]

I am not an expert on the old Armstrong AC so maybe someone will respond to the possibility of recharging it. I am not sure where Pima AZ is in relationship to Tucson but Oasis RV in Tucson is an old time Airstream dealer. They don't sell new Airstreams any more but they still service older Airstreams. You may want to contact them. They did some extensive work on my 1976 AS early last year and they do a great job. Good luck.

http://www.oasisrv.com



Don

[TomW]

My '67 Overlander's web site details some of my efforts at keeping the original Armstrong unit kicking out ice cubes:

1967 Airstream Overlander

Tom

[Inland RV Center, In]

Originally Posted by Jim in Pima

My 1975 Armstrong AC is giving up the ghost, last summer I would get
a faint odor of oil when it started, then by fall it was not cooling well
and locked up on start sometimes.
I really would like to keep it going, having seen the effort to replace it
I would like to get it recharged before the compressor is gone.
Can I ad R22 and oil and sealer to it by myself. Get a few more year
of service from it.? What equipment would I need. I live in a area where
it is doubtful I could find a professional to climb on the roof of the Airstream.
(my wife is not pleased about me doing it at 78)
Thanks

First, locate the possible leak.

Then the unit can very easily and quickly be recharged with some oil if necessary and R-22.

Your AC can be serviced on the roof without any issues as that's how it has been done foer almost 50 years.

As long as there is still some pressure left in the system, all you will need is a set of hoses with gauges and a container of R-22.

be prepared however, that for the general public to obtain Frean of any kind, is very very difficult because of todays Federal laws.

Total time, other than fixing a leak, 30 minutes.

Andy

[BIGED52]

Truck services like ThermoKing or others that service trailer cooling units andor those are located at truck stops may be willing to help you out and some even come to you. Taking the unit off the trailer would not interest me unless it was to replace it with new. However, as I was told by a local service center "Keep your old Armstrong unit as long as you are able to get it serviced as they cool twice as well as any of the newer units." I am inclined to believe that statement to be correct from what I have learned about the newer A/C units. Adding Freon to your unit should only be done by an A/C qualified technician. Ed

[Aage]

Here is a great thread on the Armstrong unit. The member that wrote it not only increased its output as an AC, but also turned it into a heat pump.

http://www.airforums.com/forums/f427...dor-76432.html

[Jim in Pima]

Back again, attempts to find the info I need as hard to come by
I found R22 and sealer on ebay, entire kit, but vendor will not say it it fits the Armstrong. I have the AS 1975 service manual that includes the AC but not a word on recharging it. Where and what is the recharge port, is it the same size as the ones on a auto? Like to find out before I remove the shroud.
PS, I live in the boonies, and if I want this fixed, I have to do it.
Thanks

[mopariac]

Originally Posted by Jim in Pima

Back again, attempts to find the info I need as hard to come by
I found R22 and sealer on ebay, entire kit, but vendor will not say it it fits the Armstrong. I have the AS 1975 service manual that includes the AC but not a word on recharging it. Where and what is the recharge port, is it the same size as the ones on a auto? Like to find out before I remove the shroud.
PS, I live in the boonies, and if I want this fixed, I have to do it.
Thanks

Jim,
I have about the same AC and last summer it locked up after it wasn't cooling as good as it use to. I thought I would have to replace it or have it recharged too. When it locked up, it shook the whole trailer like someone slammed on the brakes.

I took the inside cover off and inspected the evaporator radiator and it was almost completely block by years of dust and grime. I got a can of degreaser, soft brush and a small AC rib comb and worked on cleaning as much as I could to see if it helped. I blocked the drainage hose so it wouldn't fill with debree and block it up and fixed a small tarp that collected all of the cleaning water and sludge. I also used a spray bottle for rinsing, using hot water after I cleaned.

Guess what!!! It works like a dream again. Started right up and cooled off better than before. I would give it a shot before you try anything else.


Before I cleaned it, I was trying to find someone that knew what to do with recharging and all I found out is that these units are similar to house units and can be recharged, but you have to add a fitting on one side or another and evacuate the complete system before recharging and put in a certain weight of freon and that's all I needed to know before I knew I wasn't going to tackle it by myself.


Let me know if it works for you...I'm hoping it does.

Tharon

[adonh]

When I bought my 1976 31' Sovereign back in 2000 it still had the old Armstrong AC. When I first plugged it in not much happened very little air and and not cold. I found the same thing a previous post found, dirt in the coils. What a mess to clean. But I also found something else, the squirrel cage blower was turning when the power was on but it was just spinning on the shaft. The small allen screw that held it to the shaft had loosened over the years and once I tightened it and cleaned the coils it worked just fine.

[Jammer]

Jim,

Two things. If your unit is starting hard it is probably because the compressor is beginning to fail. Refrigerant loss would typically cause easy starts but weak cooling. Unlike automotive A/C, it's rare for RV air conditioners to develop leaks.

Second, I believe that by 1975, Armstrong A/C was using the standard 14" square roof hole in use today. If that is the case you are probably better off, IMO, replacing the entire unit if the compressor is bad.

All that said, here is the answer to your questions.

Armstrong A/Cs, like most RV air conditioners, were not equipped with charging valves when new. In production, the systems were charged through a copper stub that was then swaged closed once charging was complete. The usual strategy for service, then as now, was to install line taps like these:

Amazon.com: Line Tap Valve by Sealed Unit Parts Co., Inc.: Everything Else

They are also sometimes called piercing valves since they work by using a sharp, hollow needle to pierce the soft copper refrigerant line.

It is possible to purchase R-22 refrigerant. If you pay a fee and pass a test you can get an EPA license to purchase with any refrigerant you wish. The tests are available on-line and are not difficult to pass. For some refrigerants you don't need a license. I'm not sure whether R-22 requires one or not.

Finally, if you do decide to hire someone to repair the air conditioner in place, I would suggest contacting a commercial refrigeration contractor as they will have the skills and equipment to do the job.

[idroba]

Originally Posted by Jim in Pima

My 1975 Armstrong AC is giving up the ghost, (snip)
I would like to get it recharged before the compressor is gone.
Can I ad R22 and oil and sealer to it by myself. Get a few more year
of service from it.? What equipment would I need. I live in a area where
it is doubtful I could find a professional to climb on the roof of the Airstream.
(my wife is not pleased about me doing it at 78)
Thanks

Apparently some have found just cleaning the coils, motor and fan may help these old units but if it actually does need service of the refrigerant cycle I doubt that you can do it yourself for several reasons.

1. The refrigerant is not available to the do it yourself person any more. You must be a licensed refrigeration mechanic to purchase it. I am not sure what refrigerant you found on ebay, if it is actual R22 or some mickey mouse replacement. Sealants just don't work.

2. Most all of the AC units have no service ports on them, and one would have to be added, not easy to find them, or do that. There is a clamp on type available but they commonly leak. Only brazed or soldered on ones hold up.

3. The charge is very critical and without proper tools to measure it, whatever you put in is a guess.

4. The gages and hoses to connect to the system are an additional expense, probably around $100 even at Harbor Freight.

Yes, it can probably be serviced by a well equipped and knowledgable shop, but they most likely would want it off the AS so they could to it on their bench. The cost of removal and replacement, plus the shop costs may well exceed the cost of a new unit.

So, you might try cleaning and inspection of the exterior coils and motor, but if that does not work further self repairs may be beyond your reach.

However, best of luck in whatever you do. The comments above are from my experiences and are my opinions.

[TomW]

Originally Posted by idroba

...However, best of luck in whatever you do. The comments above are from my experiences and are my opinions.

Outstanding post, idroba. You conveyed what I wanted to post in a much better way.

Kudos.

Tom

[Inland RV Center, In]

Originally Posted by Jammer

Jim,

Two things. If your unit is starting hard it is probably because the compressor is beginning to fail. Refrigerant loss would typically cause easy starts but weak cooling. Unlike automotive A/C, it's rare for RV air conditioners to develop leaks.

Second, I believe that by 1975, Armstrong A/C was using the standard 14" square roof hole in use today. If that is the case you are probably better off, IMO, replacing the entire unit if the compressor is bad.

1. A start capacitor will also cause a hard or no start issue.

2. Airstream has never used a vent opening for an AC.

Andy

[Jim in Pima]

Thanks to all for the great reply's, So I think the plan of attack will be to make
sure the interior coils are clean, take off the shroud and clean it out, and I suspect that is full of stuff. It will soon (to soon) be hot here, over 100F most spring and summer days.

[Jim in Pima]

forgot to mention, I have a terrible problem with DESERT WRENS. They find the worse
places to build a nest, my truck was acting terrible until I found they had moved into
the air intake, leave the shop door open and by dust they have moved in.
They also moved into a roof vent on the camper I had left open. I think they
may have a home in the AC, make another hardware cloth screen

[TomW]

Birds & squirrels were known to come down my Overlander's fridge vent when the original owner still had it. I screened it off under the cover during the refurb will no ill effect on fridge operation.

Tom

[texasbound]

Originally Posted by Inland RV Center, In

1. A start capacitor will also cause a hard or no start issue.

2. Airstream has never used a vent opening for an AC.

Andy

Andy,

What AC options do you have in stock for my 74 sovereign? I'm looking for 15k.

Thanx

[Ncrango]

Hi,

For the Armstrong 14 unit, does anyone have an idea of the approximate capacity of R22 in the system?

[TomW]

What year Airstream does a 14 unit go on?

Tom