Armstrong A/C water leak

[TomW]

My Overlander has developed a roof top leak which unfortunately, appears to originate at the original Armstrong air conditioner. The water actually leaks out at the upper trim on the street side bedroom window. I blame the A/C because all the roof top seams & vent stacks have been sealed within the past eight months, and the three roof vents were sealed this past Saturday. A monsoon we had here last night deposited around two cups of water in the drip pan previously set at the window.

I’m struggling with the best way to deal with the leak. Here is what I think is accurate information: The Armstrong units are made in two sections. The outside part has the compressor, double-shaft fan motor, electrical connections, and condenser coils. The inside part only has the evaporator coils, drip pan, and a fan blade.

There are only two cut holes in the roof. The 1-inch diameter fan blade shaft, and the 3-inch diameter wiring/Freon line pass-through. Neither of these leak.

It is my understanding that the roof-top part is held on by a lot of rivets. Removing it, in addition to the hassle of drilling out a bunch of rivets, would also involve breaking the Freon connections.

When the motor was replaced earlier this year, I took the opportunity to Vulkem anything the area that had leak path potential. There isn’t much.

I’m concerned that something may have gone bad wrong (like a skin tear) since the leak developed during our recent 1400 mile trip to Disneyworld.

Plans are to pull the A/C shroud at the next dry opportunity & reassess.

Am I missing anything? Has anyone had a similar experience with an Armstrong air conditioner?

Thanks,
Tom

[thenewkid64]

Tom,

The only things I can guess would be either a rivet pulled loose or failed. Or that the shaft seal where it goes through the roof has cracked, or torn.

Pull the exterior shroud. The problem may be apparent.

[rluhr]

Tom, if the leak appears to be coming from the upper part of the streetside windows, it may be a hinge leak. Look closely when it is leaking. If you have the same hinge design as on my '68, rainwater will come in and drip off the end of the hinge or the top of the actuator arm.

On the other hand, if the leak is from the seam around the window frame, you have a leak elsewhere in the upper part of the trailer body, which may include the A/C.

-- RL

[garry]

There is a drip pan drain line from the AC that comes out at the wheel well.
I had a leak and cleaning out the drain line fixed the leak. The leak will show up in different places depending on how your AS is leaning.
Do a search and there is a good discription on the exact location of the drain line.

Garry

[TomW]

Originally Posted by rluhr

...Look closely when it is leaking...

Yeah, I was REALLY hoping the leak had something to do with the window. Unfortunately, I confirmed that the water is run-off from the inner skin, and does not originate at the window.

The thought of possibly having to break freon lines has me so angst-ridden that if it were not for the fact that my wall insulation is getting soaked, I half thought about installing some sort of gutter to catch the water. Talk about a bandaid!

Brett - from other posts, I gather you have removed a roof unit similar to mine in the past. Do you recall approximately how many rivets you dealt with, and more importantly, was there Vulkem or something between the A/C & the skin?

Thanks,
Tom

[rluhr]

Originally Posted by tcwilliams

I confirmed that the water is run-off from the inner skin, and does not originate at the window.

Forget it, Tom, the trailer is a total loss. I'll take it off your hands in exchange for a batch of your great fried chicken.

(see attached picture of Tom in his beautiful cherry-interior vintage trailer)

[thenewkid64]

Originally Posted by tcwilliams

Brett - from other posts, I gather you have removed a roof unit similar to mine in the past. Do you recall approximately how many rivets you dealt with, and more importantly, was there Vulkem or something between the A/C & the skin?

Sorry I cannot shed much more light on the issue, but I will do a brain dump

The may be vulcem between the AC and the skin. There will be for sure where the rivets enter the skin. I have no clue ow many, I remember installing an Armstrong form 76 and it had about 60 rivets. The thing is that the AC was not always a factory installed option. More often that not the dealer installed it as part of the sale, this is also why there used to be multiple awning makers that made them for Airstreams, the dealer added these too, not the factory. It could be that the unit is held on with screws instead of rivets too, on missing fastener could be your source.

That being the case, the unit IS field serviceable by a home AC person. The unit has service ports and is designed to be worked on. Unlike many of the newer (not Dometic) units. If you had to remove it and reinstall it, I would be sure to find a local AC guy that will commit to working on it. You may be able to get them to come out and discharge the system and seal it, so you can work on the roof, then you reinstall it and have then come hook it back up and recharge it. Not fun, but maintains the vintage unit, and reduces the total cost to a couple of service calls, and some freon. The reason you want to seal the unit is to maintain the integrity of the dryer and compressor. Your humid air getting to the internals will cause problems down the road.

If the leak is consistent from the same window, your leak is likely on that side of the coach.

[TomW]

The rain let up enough yesterday long enough for me to pull the A/C shroud, and look things over.

The shroud screws directly to the top of the unit, and to angled pieces of aluminum at the bottom. The angled pieces are connected to the unit. After removing the angled pieces, I found five, very rusty sheet metal on screws on each side of the unit which serve to screw it to the roof. Coupled with the three screws on each forward & aft end, there appear to be 16 screws holding the unit to the roof.

One particular screw had not been installed correctly, and the unit was obviously loose at that location. I managed to install a Vulkemed Olympic rivet before it got too dark to continue.

We had another monsoon last night (flood warnings & everything). This morning I went out to find that, although the leak had been seriously curtailed, it was not totally gone. But I feel encouraged because the last rain left at least two cups of water in my drip pail, and this morning I had maybe a tablespoon.

The screws are rusted/eroded to the point that there are no screwdriver features left. I think if I replace all the screws with either new screws or Olympic rivets, I should be okay.

Comments?

Thanks,
Tom

[thenewkid64]

Originally Posted by tcwilliams

The screws are rusted/eroded to the point that there are no screwdriver features left. I think if I replace all the screws with either new screws or Olympic rivets, I should be okay.

Comments?

Tom,

Based on the picture and the blue outlined section , I would do all of or some of:

A: Remove all fasteners on that side and try to seal under the flange as well as check for other penetrations of the roof.

B: Use a slightly larger screw in place of the current ones, and maybe add a few more. Drilling out the rivets to R&R the AC will be a bear.

And.....

C: See if there is a way to fix the "low spot" on the roof. Any time water is allowed to pool, there is a greater risk of penetration to the interior.

I would be willing to bet that the shanks on the extremely rusted screws are all shrunk, or corroded/rusted to the point that they are allowing water to pass, allowing the now minor leak. The trip to FL and the associated towing could have created enough vibration that the screws now leak. Since they are steel, you may have to grind them off form the top and pot them with vulcem. Then add new screws into new holes to fasten the AC back to the roof. The one blessing is that this is all under the shroud, so no matter how messy the repair is you will be the only one that knows

[TomW]

Originally Posted by thenewkid64

...B: Use a slightly larger screw in place of the current ones, and maybe add a few more. Drilling out the rivets to R&R the AC will be a bear.

And.....

C: See if there is a way to fix the "low spot" on the roof...

In somewhat of a dichotomy, new screws should make future R&R easier (as long as the screws don’t rust too bad), but Olympic rivets would ensure I would not have to deal with rusted fasteners eroding away again. I would like to think that I will be able to keep this air conditioner running indefinitely, but who knows if that will be the case. Yeah, I know, life’s tough.

I went with an Olympic rivet for the one screw addressed because the bad fastener was in the “puddle zone”. The hope was that the rivet’s legs would help pull some of the depression out. It helped.

I agree that it would be much better if the puddle were not there. But since I am not inclined at this time to pull the inner skin to add cross-members, the only other solution that comes to mind would be a ridiculous looking miniature “arch of St. Louis” over the roof-top unit complete with guy wires. Do you have a better idea?

Thanks,
Tom

[thenewkid64]

Originally Posted by tcwilliams

I agree that it would be much better if the puddle were not there. But since I am not inclined at this time to pull the inner skin to add cross-members, the only other solution that comes to mind would be a ridiculous looking miniature “arch of St. Louis” over the roof-top unit complete with guy wires. Do you have a better idea?

All I can say is build it in Aluminum instead of Stainless Steel!

The question that this poses is "what caused the low spot?" Was it the way the AC was installed? is it the weight of said AC? would removing all of the fasteners on that side and adding a sister piece of stiffer aluminum riveted to the skin and positioned under the AC flange, help to lift the low spot?


I truly believe once you replace the fasteners with new, and add generous amounts of sealant while doing so, the leak will go away. I would still check this on a yearly basis though to be sure that the rivets are holding.

[TomW]

Originally Posted by thenewkid64

...The question that this poses is "what caused the low spot?" Was it the way the AC was installed? is it the weight of said AC? would removing all of the fasteners on that side and adding a sister piece of stiffer aluminum riveted to the skin and positioned under the AC flange, help to lift the low spot?...

Unfortunately, the A/C unit sits too far inside the two main ribs to scab in any stiffener pieces. I guess I could, and modify the shroud to allow the pieces to extend, but am worried it would look bad.

I too wonder why there is a puddle zone. At first I thought a less-less-svelte technician had serviced the unit in the past. But a post that discussed hail damage diminishing over time reminded me that the roof panels are in tension. Even with the added dead weight of the compressor, one would think all the stresses associated with the Airstream just plain sitting in the driveway would keep the roof-top level. Then I remembered the way my Overlander sat for 23 years.

The PO had placed jack stands under the frame right at the bumper. Deep depressions in his asphalt driveway indicated the stands had been there for quite some time. When I took possession of my Overlander, it had one very obvious flat tire.

Several months ago, I wondered if the fact that the jack stands were supporting the load contributed to how good my axles appear to be. They may have. But now I wonder if the Overlander was trying to fold up like a book, and the puddle zone around the A/C is the net result. Now that we are actively enjoying our Airstream though, maybe the puddle zone will disappear. Yes, I find that hard to believe too!

Tom

[till]

Tom,
This tread has been a real adventure. I to have the same depression at the rear of my Armstrong AC. You can see the depression at my foot. Now I'm wondering if that is the source of one of my mid trailer leaks.
As for fastening what about Stainless steel screws?? When my interior skin comes out I will post my findings to this thread.

[TomW]

Originally Posted by till

...As for fastening what about Stainless steel screws??...

Thanks Tedd; I hate it when I lose sight of the obvious.

Tom

[john hd]

looks like those will do the trick!

john

[TomW]

Nice day here today in Alabama - mid fifties & clear. Perfect weather for a roof repair.

The sixteen screws holding the unit to the roof all came out with vice-grips without too much trouble. Most of them had to break loose, so I figured those were still sealing. If you look carefully at the picture below, you can see rust on the shanks of the screws in the puddle zone. Those particular screws did not put up much of a fight coming out.

Whatever putty Airstream used to seal between the roof & the unit was still pliable. After removing the screws, I ran a putty knife around the sealing surfaces. The putty had de-bonded only in the “puddle zone” where the screws had loosened. And it was only between the putty & the unit, not the roof & the putty.

Instead of removing the putty, I cleaned everything & injected Vulkem between the sealing surfaces & into anywhere I thought water might go. Even with the screws removed, the unit would not lift up high enough to do a good job removing all the putty, so it was left in place. Also, it appears to me that running a bead of Vulkem would have been easier for the factory to originally do. Since they chose putty, I decided they may have been considering some aspect I have overlooked.

The original screws were 10X1/2 pan head sheet metal screws. All I could find locally in stainless steel were 10X3/4, but the extra 1/4 inch won’t hurt anything.

The shroud was re-installed with 8X1/2 pan head stainless steel sheet metal screws.

I feel pretty good about this repair solving my leak problem. If nothing else it means Rluhr will have to wait until another rally to get another batch of my fried chicken!

Tom

[thenewkid64]

Tom,

Sounds like a good repair that should last for another 30 years!

Are you going to leak test it with the garden hose, or wait for the rains?

[TomW]

Originally Posted by thenewkid64

...Are you going to leak test it with the garden hose, or wait for the rains?

Test it ?!?! Why would it leak after all that effort?

I don't know; It's kind of like looking at the bulletin board after a test you think you did really good on. Too often I used to see a grade I did not like too much.

Though with Vulkem's cure time, I have a lot of time to make up my mind.

Update: It's been about a month with occasional rain except for yesterday when it poured AND there were tornado warnings out due to the wind. This morning I checked the interior, and everything was dry. I believe I will declare success & move on.

Tom

[till]

In post #13 I said that I would post my findings about the dreaded "AC sag"

Well this is what I uncovered. There are two extra supports that run along the roof line from about the galley to the bath. These are just out board from the two main ribs that run down the center axis of the trailer. (I will try to up load photos to my album under damage found.) The two supports just under the compressor section (aft on the AC unit) have poped out rivets. Also, two 4 foot sections of main roof brace are cracked almost in half. Plus all but one rivet poped out. The only way I see to fix this is by removing the cieling skin and getting in at the poped out rivets and broken braces.

[TomW]

My Overlander has been out on the road for eight years & 35,000 miles now, and we're now starting to experience the new stuff installed during the refurbishment wearing out.

There's one, original, from-the-day-it-was-new problem I never addressed until now that has now been fixed - the Bay Breeze sweating on one of the single beds. For some reason I lived with it; no longer - It was fixed this last weekend.

The Factory did not install any stringers between the ribs between which the A/C is mounted. The unit is mounted considerably closer to the FWD rib than the aft. Settling occurred which left the unit kicked-back looking forward. As a consequence, all the cold condensate collected aft could not drain easily, and allowed sweat to build up.

There is no easy remedy to the lack of support not incorportated in 1967.

Jump forward to this weekend, and my bubble-level tells me the unit leans toward the street-side by a quarter-bubble, and aft by a quarter-bubble.



Airstream's placement of one of the condensate drain-tubes on the curb side (LH in the image) of the unit was obviously destined to remain dry. Moving the drain to the aft part of the unit appeared to be in order. Drilling the pilot hole afforded excitment.



I had to wait through almost two cups of condensate before the next step.

The curb-side fitting was relocated, and new copper fitted & painted to drain the works.



Nothing like a good improvement on sixties technology.

Tom