Help needed with A/C drip

[nickcrowhurst]

My trailer seems determined to drip water from the rear streetside corner of the interior ceiling cut-out when and after the A/C has been running. The A/C is a Coleman Delta TX.
Two years ago I traced the drip to a split in that corner of the drip pan. I sealed this from inside the trailer, and enjoyed a drip free few months. Success!
The next year the drip returned, and I traced this to a blocked drain tube. I blew up the tube, received a face full of dirt and water, and the drip went away. Success!
This year, the drip is back. I can see no split in the tray (although vision is very restricted). My 2 year old repair is good. The drain tube is clear. I went on the roof, removed the cover, grille, and steel panels that hide the cooling radiator and fan motors. I cleared out leaves, and a mud-daubers nest, but could not see the drain pan, or the drain tube. I replaced the panels, grill and cover. By getting my long-suffering, angelic and beautiful wife to lie on the ground and blow up the tube I eventually traced the point where the drain tube exits from the drip tray. It is on the streetside, half way along the ceiling cut-out, and mainly obscured by electrical wiring. There is no sign of a leak at the junction. The drip is from the outside of the pan, and I can catch a glimpse of the wood between the roof and ceiling. This is wet. This corner is clearly a low point, and the symptoms indicate to me an overflowing drip tray, or a crack in the drip tray in some invisible place, or perhaps condensation where there should not be condensation. That being said, I can't seem to access it from below, or above. I'm full-timing, in a field, so removing the unit from the roof would be distinctly challenging. I presume I would then have to turn the roof unit over to gain access to the drip pan. Alternatively, perhaps by removing the interior ceiling unit, I could access more of the drip pan. However, this would involve breaking the joint between the ceiling and roof joints, and this I am reluctant to do. The joint is sealed with some non-hardening sealant. The literature on the unit does not show sufficient detail for me to understand the best means of dismantling.
Does anyone have any guidance for me on how to trace this leak, before I start more internal demolition. I will be away from the computer until Monday, but meanwhile I would be grateful for some guidance. Thanks.
Nick.

[john hd]

nick

i deleted your duplicate thread.

good luck on finding your leak! you may have to have the entire unit removed to find the source of the leak. sounds like a hidden problem!

john

[Condoluminum]

Nick

We had similar leak in our '88, with the TX, and were sure it was the drain tube until getting help here, and discovering it also leaked water inside when it was raining... Hmmm.. The foam square gasket seal on roof under A/C unit is prone to drying out and cracking, after which it is no longer waterproof... Easy test is to sit inside and have friend outside with hose spray water at unit from all sides and see what comes inside... If it leaks when shut down, it is probably a gasket...

Cure was to have shop unbolt and lift unit, replace gasket, and re-attach to roof.. Bingo, no more leaking or dripping rain or shine... If you have good access, ladders and strength, you could try it, but labor about an hour, and gasket cost about $20...

John McG

[nickcrowhurst]

Thanks to both Johns. I hadn't thought about the main gasket, as the unit drips in dry weather, but if condensation forms on any part of the outside of the unit, it could end up passing through this gasket. I will first try tightening the bolts that squeeze together the roof and ceiling units. Also, I'm looking to replace the sun-decayed outside cover, but the RV catalogue I use lists dozens of AC units and the replacement covers, but not for The Coleman Delta TX. Any ideas on a supplier, anyone? Thanks again.
Nick.

[genearnold]

Nick,

I have a drip-pan problem with my rear A/C. I bought the trailer in May, 1999 and the first hot-weather trip I took to Nebraska I discovered an overflowing drip-pan that soaked the foot of the bed. I tried to fix it but couldn’t so I took it to my Airstream shop to have them install a new pan. When I returned to pick up the trailer they told me they didn’t finish the job since to remove the outside unit might destroy it as it was gooped with Vulkum.

I’ve put up with it. It is OK in low humidity desert areas but I never use it where I really need it. I have a friend who is the shop manager at another service shop and he is willing to help me take care of the problem now that the off-season is here and he has more time. I’m aware that in repairing it I may end up buying a new A/C.

Hope yours is not hard to fix.

Gene

[nickcrowhurst]

Gene and John, I followed up John's suggestion. I removed the internal plastic cover and the self tapping screws that held a large steel cover plate. Removing this plate then revealed the three 9/16th inch bolts which hold the roof and ceiling units together. According to the installation manual, these should be tightened to 5 ft lbs on installation. As my gasket is probably fifteen years old, I tightened the bolts a little more (9/16th socket and 3 inch extension on a ratchet wrench) until they were "snug", but not tight. I could hear the old gasket crumbling a little as I tightened the bolts. The evening was warm and humid. I ran the A/C for an hour. Water dripped twice a second from the overflow pipe, and there was only the smallest dampness where the original drip has been. Thjank you, John. This may be a worthwhile maintenance item for A/C units, and it's only a ten minute task. A proper repair will doubtless involve fitting a new gasket.
Nick

[Condoluminum]

Nick-

If gasket material made crunching sounds, then the soft pliable foam material has lived past the end of its useful life... When it gets hard and crunchy and cracked, it does not achieve its original objective of keeping water on same side it started...

When and if you can get a ladder and plywood platform, you are going to need to unbolt the unit, lift a few inches, and replace the square main gasket... They are available at most RV shops (happily even Airstream uses standard 14 inch square unit..) and it's good to have it in hand, in case some tools and help should happen along... If not, with scheduling, it's less than a 1 hour job at a service center..

John McG

[nickcrowhurst]

John, yes, you're quite right, of course. I'll get a new gasket, but I'll put off the evil day as long as I can. That unit weighs 100 pounds, and lifting it alone while standing on the roof is an interesting challenge. I have access to two 10 foot high step ladders. I could sling an 8 by 2 between them with a tackle in the center. Getting a dealer to do it would be very sensible, but we forum members like to be independent! Thanks again.
Nick

[Pick]

Nick, if you need a hand with that, let me know. Be glad to help you

[nickcrowhurst]

Originally Posted by Pick

Nick, if you need a hand with that, let me know. Be glad to help you

Mike, many thanks for that. When we've got over a cold bug, we'll come and find you. I'll PM you soon. Nick

[nickcrowhurst]

Yesterday I bit on the bullet, and replaced the Coleman Delta T/X A/C roof gasket. Procedure, carried out in the middle of a field, solo:-
1. Disconnect 110v supply after switching fridge to gas.
2. Remove knobs, 2 screws, and hence the inside plastic cover.
3. Remove the 6 screws holding the steel plate that is revealed, lower the plate a few inches, disconnect the connector for the heat strip wiring. Put the plate aside.
4. Disconnect the two electric connectors on the street side of the unit.
5. Disconnect the two wire nuts and earth wire on the kerb side of the unit. Release the cable strain relief, and pull the wires through the hole.
6. Draw with a pencil on the ceiling round the inside unit so that you can replicate the position on re-assembly. With a ratchet and 3 or more inch extension with a 9/16th inch socket, release the three looooong bolts that secure the indoor section of the A/C to the roof section, and carefully put it aside.
7. Climb up on the roof of the trailer. I can park my truck alongside the the trailer, and hop off the side of the truck bed on to the roof by pulling on the awning rail. There are many better ways, well documented on the forum! I prefer to stand on the transverse rivet lines when up there. Remove the 4 obvious domed nuts securing the shroud. Lift the shroud off, up and then forwards. Put it aside.
8. With leather gloves on, take hold off the whole unit by strong points, and gently tilt it on its street side edge until it is almost in balance. Prop up the unit with a piece or two of timber, backed up by perhaps a gallon fuel can to cushion it if it slips. Use whatever you feel will adequately hold the unit. It is heavy!
9. Sweep out or vacuum out all the old leaves and dirt revealed. Pay particular attention to any drain pan and tube.
10. Peel off the old gasket, use a knife gently to slice off any recalcitrant pieces, and then clean the gasket area with mineral spirits.
11. Take the 14 inch square gasket with its backing paper still on. Slide it down towards the opening in the roof, and wriggle the dangling electric wires through the hole in the center of the gasket
12. Peel off the gasket backing paper, and carefully apply the new gasket to the old gasket location.
13. Gently lower the unit back down onto the roof in its correct position. Breath a sigh of relief. Don't replace the shroud at this point.
14. Off the roof, and back inside, replace all the parts and wiring connections in the reverse order from dismantling. The three long bolts are slowly tightened in rotation to 5 ft pounds (60 inch pounds). This is very low, so as not to over-crush the foam gasket. Checking this torque every couple of years is on my preventative maintenance list.
15. Reconnect the 110v supply, and operate the unit. At this stage, I found the fan was fouling its shroud, and making a harsh scraping. I disconnected the 110v electric supply, went up on the roof, waggled the fan motor on its very sloppy mountings until I could rotate the fan manually with no friction, went down to reconnect the 110v, tested the unit to find the noise had gone. Smiled.
16. 110v disconnected. Back on the roof. Shroud installed. 110v reconnected. Job finished.

Nick.

[Condoluminum]

Nick-

Thanks for update on replacing A/C foam gasket.. I'd say "sounds like fun.." but it really didn't.. I'm amazed you were able to plan ahead and take pieces of lumber, gas can, knife, mineral spirits, whisk broom and other items onto roof first try... Somehow I suspect several climbs up and down onto roof during external phase of project...

The one missing item was the "Hose Test"... Did you have the courage to spray a water hose at the unit after completion to assure the problem with water leaking in had indeed been addressed?

John McG

[nickcrowhurst]

John, you're quite right, the post omits the descents for the brush and other forgotten items! The old gasket didn't leak after I had tightened it, but I replaced it because I could hear it was brittle. I was surprised to see that the old gasket had disappeared, or had never been fitted, to the rear edge of the unit. I was able to take the opportunity to make a better job of a crack repair in the plastic base plate that stays on the roof, and to clean out the condensate reservoir. Unfortunately, leaves and debris can only be cleared from this reservoir when the unit is removed from the roof. I haven't tested for waterproofness as my inch pound torque wrench is a thousand miles away, so I have guessed the torque. The torque wrench I carry with me is foot pounds, and insufficiently accurate in that range. I won't be taking the trailer out of its pole barn until I've checked the torque.
I'm still trying to find a replacement shroud for a Coleman Delta TX. Anyone??
Nick.

[nickcrowhurst]

An important addition to item 12 on my action list at post #1 :
If the trailer is fitted with an Airstream drain pan below the air conditioner, with the hose drain down between the skins, drain holes need to be cut in the 14" square gasket to allow condensate to drain from the whole Airstream pan to the small reservoir drained by the tube. The small reservoir is within the area surrounded by the 14" square gasket. I cut a 1.5 inch section out of the rear section gasket, near each corner. If the air conditioner is fitted direct to the roof of the trailer, without the extra drain pan, the gasket is all that keeps rain and condensate out of the trailer, so it must remain intact. Don't ask me when or how I discovered this.
Nick

[nickcrowhurst]

Just a reminder that a routine maintenance task, perhaps once every year, should be to tighten the bolts holding the air conditioner onto the roof of the trailer. On my Coleman Delta unit:
1 Remove the slide-off control knobs on the front of the unit.
2. Unscrew the two screws that hold the inner plastic shroud, and remove the shroud.
3. Remove the 6 self-tapping screws that hold the large steel cover on the unit. Lower the plate carefully, and it will hang on the wiring tube that is revealed.
4. This gives access to the heads of the three securing bolts. With a 9/16th socket, and an extension drive, tighten the bolts gently to only 60 inch pounds (5 foot pounds). This produced nasty crunching sounds as the foam gasket was compressed, even on my 9 month old gasket.
5. Reverse 1,2, and 3 to re-instate the device.

Performing this ten minute task could prevent rain water leak problems.
Nick.