step by step ac gasket replacement

Discussion in 'Heating / Cooling Systems' started by andleton, Jul 22, 2010.

  1. andleton

    andleton "Happy Campers"

    Messages:
    149
    Likes Received:
    0
    Joined:
    Aug 31, 2009
    Location:
    Roanoke Rapids, NC
    My coleman ac mach 3 is leaking around the gasket.Does anyone know where I can get step by step instructions on how to replace it.Any help is greatly appreciated.
     
  2. awsandlin

    awsandlin Active Member

    Messages:
    1,333
    Likes Received:
    12
    Joined:
    Mar 3, 2008
    It is really not too hard to do. The hard thing is just getting your A/C off.

    From inside, you need to remove the complete cover, which means you will need to disconnect the wiring.

    At that point you should find some long bolts that hold the A/C unit to the roof. There should be four of those. You need to remove them.

    Next, you have to get the unit off the roof. You really should get some one to help you with this part. The unit will weigh somewhere between 100 and 150 pounds, not real bad but it is hard to manover. You could get you a small sheet, say 4 X 4 of plywood to set the unit on and work it over to the edge where you can then get it off the camper.

    Now, clean the roof and clean the bottom of the unit where the gasket goes. Clean it very well. There are also some leveling gaskets that will come with your kit. Toss the old ones, but just make a note of where they are so you can put the new ones back in the same place.

    Now that everything is clean, you are ready to put it all back together. This is where you need to be careful that everything sets in place without damage to your new gasket. You don't want to slide the unit back in place with the new gasket, but rather set the unit back in place. Again, you need some help on this and a good plan.

    Once the unit is back on, raise your roof and go back inside. Replace your four bolts. You should tighten them down so that the gasket is displaced by 60%. I don't know how you tell that, but you get the idea. Basically, you don't want to tighten your new gasket down into a pancake.

    Put everything back together inside and then go camping.

    There is some stuff that sort of makes an air duct that you may need to repace with some duct tape, (true A/C duct tape). Also, the metal piece that sets in the cut out really does not have to come out unless you need to clean it.
     
  3. andleton

    andleton "Happy Campers"

    Messages:
    149
    Likes Received:
    0
    Joined:
    Aug 31, 2009
    Location:
    Roanoke Rapids, NC
    Thanks so much for your help awsandlin.It is good to know there are still people who are willing to help others.Thanks again,greg
     
  4. awsandlin

    awsandlin Active Member

    Messages:
    1,333
    Likes Received:
    12
    Joined:
    Mar 3, 2008
    You are certainly welcome. I hope all goes well for you when you change out your gasket. Please tell us how it goes.
     
  5. twstdpear

    twstdpear Party like it's 2012!

    Messages:
    585
    Likes Received:
    4
    Joined:
    Jan 18, 2009
    Location:
    Northern VA
    I noticed a leak recently due to my bolts backing off, which apparently happened during our FL trip at the end of August. Re-tightening the bolts didn't help, so I replaced the A/C gasket today. It is as easy as awsandlin says it is. It'd probably have been a little easier if we didn't have a highwall, which just made getting to the roof a little more complicated as well as getting the A/C off the roof.

    Instead of plywood, I wound up using a thick, heavy duty cardboard box from something we purchased recently. The box was cut down so it would lay flat in a double layer. Since my A/C shroud seems to mostly be cosmetic, I decided to remove it. After that, I nestled the box right next to the A/C, rolled the A/C over on its side, spun the cardboard to move the A/C close to the side of the camper with the bottom facing out and my dad helped me lift it down. I don't think you necessarily HAVE to lift it down, especially with it spun around so you can access the A/C's bottom while standing on the ground.

    I found it a bit easier to do the inside work by lying on the bunks with the roof up only 15"-18" or so and was very deliberate and careful about how I moved around to make sure there was no damage since that's not the normal weight carrying position for the bunks. This granted me enough leverage to fine-tune my placement of the A/C since it was close, but not quite perfect.

    Having done this, I offer four pieces of advice:

    Also, make sure to use some BLUE Loctite to keep the long screws in place. They will have a tendency to back off slowly otherwise and then you'll get leaks. The screws on the outside cover should also have some Loctite applied to them.

    To remove the old gasket and adhesive, I found a tape/label remover at the BORG called "Mostenbocker's Lift Off 2". It's amazing for removing goopy tape, labels, and adhesive residue, and isn't noxious like goof off. (BORG = Big Orange Retail Giant = Home Depot)

    Replace the foam levelling/support pieces as well as the gasket. The new one may not be the same thickness as the original was originally, or it might have different compression characteristics. My new one was made out of Micro-cell (aka Minicel or Minicell) foam and seems like it was a good bit thicker, and I think it was a better quality gasket than the original, too.

    Test the seal on your gasket before trusting it. Fully set up your pup and really drench your roof and A/C with water from the hose, and if possible leave it set up until a heavy rain storm passes. My old gasket felt dry after the hose and before a heavy rain storm, but wet afterwards. It wasn't actually dripping, but I didn't want to chance anything.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.