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Old 06-10-2018, 05:01 AM   #1
FloridaFlockers
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Roof Leak Around AC Unit

We have a 2017 3820FK and less than 2 weeks ago we both retired (quit for now) and became full timers. Till a week ago our rig had only moved a few miles since we bought it. Then we headed out and our 1st trip was 400 miles stopping in Tallahassee for a week or so. Till recently we've had no rain leaks. So that's the setup. Then 2 days ago it poured down rain and noticed a leak, a few drips at a time, from the ceiling in back over the bed. Although not 100% certain betting the water is coming from around the rear AC unit. Got up there looked around and can see the foam gasket(?) under the AC unit. Did some searching and read all the good words about Dicor 501 sealant so bought 2 tubes to try to make a new bead around the base of the AC unit. The problem I have is that I can't get tube far enough into the gap to ensure a proper bead. The truth is I could care less about a sexy looking bead if I could just get a good seal. Thinking the real fix would be to lift the AC unit and install a new gasket and since we are under warranty till Aug could just go to CW and say fix it but.... so far with 2 other CWs (Charleston & Myrtle Beach) we have had nothing but miserable experiences. To compound it now we are FT, can't be homeless for weeks/months waiting for CW to repair, and we did not buy from the Tallahassee CW. So cutting to the chase..... anyone have any experience with the home spray in sealants/insulation like Dow Spray Foam? Will it bond to the rubber roof? Have used it at home and know it will fill the gaps but not certain it will bond to the rubber roof. Nor do I want to damage the rubber material in the event I do have to return to CW. Thanks, Joe
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Old 06-10-2018, 05:49 AM   #2
WeBeFulltime
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If I was faced with this I WOULD NOT under any circumstances try to seal it myself using the methods you mentioned nor would I take it to ANY CW for repair! I would ask around and locate a reputable RV repair business that makes "house calls". You should get better results and have almost zero down time.
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Old 06-10-2018, 06:38 AM   #3
1retired06
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Agree. Likely leak candidate could be a compromised seal, and unit must be pulled to verify and correct. Not that hard if you are handy. May also be the AC unit simply needs to be tightened up. For quiet system, lag bolts at the roof. For traditional, four long bolts inside the unit after pulling the vent. Might also check drain holes for possible block, by removing the cover and inspecting.
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Old 06-10-2018, 10:44 AM   #4
jimcol
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1retired06 gives some good advice. Past post have indicated the factory either over tightens the units compressing the gasket too much or under tightens them, both leading to leaks. Checking the drain holes in the A/C pan is also a good advice. Not hard for them to get blocked by leaves or other debris. Another common source for a leak over the bed is the OTA antennae. The boot covering the coax where it goes through the mount/roof gets pulled off. Couple of dabs of silicone caulk before putting the boot back in place generally fixes this issue.
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Old 06-10-2018, 10:57 AM   #5
DQDick
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CW is also not the only Montana dealer. Call Keystone Customer service, explain your situation and ask for a list of dealers near you. Call them and explain your situation and see if you can find one that will accomodate you.
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Old 06-10-2018, 04:48 PM   #6
Thunderman
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Tighten those 4 bolts holding the a/c down. This is not uncommon.
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Old 06-18-2018, 06:47 AM   #7
FloridaFlockers
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Time for an update, decided to go with a local RV outfit (Fla Ga RV Repair) and pay out of pocket (even though still under warranty) vs going back to CW. Called them on a Sunday and they were out in about 2hrs. Tech went up and said AC bolts were not tightened down. Once again, this forum provided great insight, read above posts. I watched and when he tightened 4 bolts the AC unit dropped about 1/2" all around. A day later another downpour, and leak was significantly reduced but still a leak. Called them back and this time owner + helper came out. They figured that while it was loose some debris might have been lodged under the foam gasket. They pulled the unit (that was simple) and inspected the gasket and wiped the rubber roof clean. Some of the rubber roof around the leading edge was wavy and they were concerned about putting it back down and there being a seep point. So they slightly lifted the rubber roof around the holes and slipped a 1" Wide x 1/16"(?) Thick rubber material around all 4 sides + the middle. The rubber material slid under the rubber roof created a slight rise for the AC unit to sit on. So between the thorough clean, slight rise, and reseat no more leak and we've had plenty of rain in the FL Panhandle to OPs check the fix. Just to clarify, the rubber material slid under the rubber roof creates sort of a dam around the AC unit.
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Old 06-18-2018, 06:51 AM   #8
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Good to hear you got it fixed.
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