Skip to main content ↑ ↓
Topic: Roof A/C seal. (Read 905 times) previous topic - next topic

Roof A/C seal.

How hard is it to lift the roof air condition unit out to replace the seal? (89 GV with Coleman units) It leaks terribly and it rains here every day. If I do take it apart can a home depot dense foam weather strip work in place of the factory part?
I'm sure I"m not the first to face this.. You folks always come to the rescue!
Andy 1989 U300 40'

Re: Roof A/C seal.

Reply #1 –
My '89 GV front Coleman AC leaked bad also. Turned out the four bolts were way way loose!!  I tightened them (from inside the coach) and the leak stopped. Of course, it depends on whether your seal is shot or still good. I don't know how others would do it but I would think you could loosen the four corner bolts from in the coach, after removing the inside cover. Then make a platform high enough to mount  a couple of jacks (plus a piece of plywood on top of them) and raise the AC just enough to replace the foam seal. A seal made just for your AC is not that expensive and is a better bet than fabricating something yourself. Leaks cause a lot of damage!

Method described above is for one man, with a bad back, and having to do the repair outside.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Roof A/C seal.

Reply #2 –
I replaced mine with a part I got from dometic.  It is a crushable gasket that you can not tighten down too much but have to have it tight enough not to leak. I do not know if coleman is different but I would think they are similar.
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Roof A/C seal.

Reply #3 –
Sealed mine down using the old gasket and clear RTV, so far so good been thru several thunderstorms in Camp Verde.
Steve & Nancy Snow
1987 GV 40'

Re: Roof A/C seal.

Reply #4 –
did mine too on the old 93 GV we had and I just took the inside cover off then tightened down the hold down bolts and it stopped leaking. I did not care if I damaged it more as when spring came I took the unit off the roof (easy job) by just lifting it up and laying it on its side. I then cleaned the seal up and caulked it both sides, no more leaks. Try just doing the bolts first at least to stop the water.
John H
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Roof A/C seal.

Reply #5 –
It is easy. You don't remove the unit, you roll it up on it's side. Remove old gasket, install new and lower it right back in place.
1994 U280, Build 4490
Deming, NM.

Re: Roof A/C seal.

Reply #6 –
Here's a heads up.  When servicing you Roof Top AC unit identify brand and model number you have.  While on your travels keep a eye open for discarded similar units at local RV Shops. What you want is the fan motor that works.  Good used ones should be about $25.00, where as a new one is $200. Coleman and Dometic never built these units to be used by Full Timers.
Steve & Nancy Snow
1987 GV 40'

Re: Roof A/C seal.

Reply #7 –
Particularly with two people, it is very easy.  The A/C unit (non-ducted) is not that heavy, but is bulky.

Turn off 120 VAC power.  Remove the ceiling unit (inside coach).  Remove the 4 hold down bolts holding the lower unit to the upper unit.

Go up on the roof.  I take a piece of plywood to set the A/C on while I clean up the gasket area.

Install new gasket.  Tighten down until gasket is about 1/2 compressed.  DO NOT OVER-TIGHTEN.

Particularly if this is the OE gasket, don't even waste time with it-- gaskets are inexpensive-- water leaks are NOT.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020
 

Re: Roof A/C seal.

Reply #8 –
You Guys rock!! I dug in during the 20 minutes it will be nice here this week. As you guys said it really isn't that hard of a job. Undid the four bolts and lifted the unit up and moved it out of the way. I didn't have time to get a gasket so I fabricated one out of a garage door seal and some good ol RTV. Thanks for all your suggestions!
Andy 1989 U300 40'