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gordon23 · 08-23-2009, 12:14 PM

Have a water leak around the rear A/c (small coleman unit) over the bed.

Person told me to replace the foam gasket it sits on.

Is there a page anyone has found that would help me do it right.

thanks......"again"

TXiceman · 08-23-2009, 12:40 PM

never seen a site with the instructions. Just use the installation instructions for a guide. First buy a new gasket and use no adhesives.

Basically you will need to remove the inside cover and trim first. Trip the breaker to the A/C unit and then open the connection box for the power. Check to be sure the power is off with a meter. Now disconnect the power at the terminal strip or the wire nuts and pull the power wire back out of the way.

Now locate the four hold down bolts and take them out. Place some wood or plywood up on the roof to support your weight if it is not a load bearing roof. Lift the A/C unit up and tilt it back or over to a side. It is best to have a helper here to steady the unit while you pull off the old gasket. Clean up the area on the A/C and roof. Set the gasket on the roof centered over the opening. Now pick the A/C unit up and set it down directly on the gasket and center it in the opening. Now back inside.

Check to see that it still centered in the opening and reassemble the hold down clamps and bolts. Go around and tighten the bolts evenly and compress the gasket evenly. Do not over tighten. Check the installation instructions to see how much to tighten the bolts. Some have springs in compression to maintain pressure on the gasket.

Hook the power back up and put on the inside trim and you are finished. In about a month, it is a good idea to check the bolts to see if they are still tight.

You have to be careful tightening the bolts as on the newer units, the pan is pretty thin and is easily warped and the fan will then hit the venturi or the fan housing.

Ken

Vetrncwby · 08-23-2009, 12:59 PM

Thats how I did it!

Triker56 · 08-23-2009, 02:44 PM

You may want to tighten the bolts down some first to see if leak stops.
Not too much needed.

Also check the drain pan on roof for being plugged.

gordon23 · 08-23-2009, 05:40 PM

I don't have the new gasket yet.(Sunday you know and why would RV parts be open in the middle of summer on a Sunday, just when people have time off work to do things) I know that's a useless bit of Bitc....ing.

Anyway, you say not to use silicon etc to seal the contact with the roof. Or the a/c I guess. But my MH is older and has a very pebbly surface to it. Not sure how else to describe it but thought a bead of silicon of the roof first would help fill the hills small gaps. I was thinking that this is why it leaked, as the foam got dried out and doesn't compress into the bumpy surface that well.

Can you comment on this aspect of the repair. thanks.

JimM68 · 08-23-2009, 08:18 PM

I wouldn't use any goop on it. The gasket was made to seal without goop.
If I did use goop up there, it would be goop made especially for use on a rubber rv roof.

Ray,IN · 08-23-2009, 08:42 PM

No adhesive! First check something. Remove the shroud and clean the water collection pans under the condenser and evaporator coils( take care not to bend any coil radiating fins).Insure the drain holes are clear from each pan, and the large pan that holds the entire unit. Then run the unit to check for that leak. If the leak persists then you can move to replacing the foam gasket_exactly as Ken said. The reason I say no adhesive is that this foam may melt upon contact with some adhesives/sealants.

TXiceman · 08-24-2009, 05:49 AM

The gasket is made soft and to seal without any adhesives. But as suggested, try tightening the bolts just a bit and see if the leak stops and also make sure the drains are clear.

Ken

gordon23 · 08-31-2009, 06:48 PM

Phew........just finished the gasket replacement on both A/C's and I have a couple of alternative suggestions that came from the RV service centre in town.

1. As several have said.........no goop!!!
2. When you are ready to apply the new gasket just peel the sticky side protection and carefully apply it to the unit that is sitting on it's side. This needs attention to keeping the gasket straight and put it where it makes contact with the roof. ie) any gasket hanging over the edge of the cut-out in the roof is not doing any good.

3. be sure to use a spacer under front and back if it does not have a serviceable one still there. This prevents over compressing the gasket which destroys it's water barrier effect. This is closed cell foam and works best if compressed to about half it's new dimension. Snug up a half turn or so after a couple of days on the four long bolts.

Note: The guy that fixed my front unit (probably years ago) pulled down so hard on the front two bolts that the gasket was paper thin. As it aged it became next to useless as a water barrier. Poor method doesn't show up until years later but can cause a lot of grief and water damage to the headliner, underlay etc. etc. Been there now.

So I'm set for rain,sleet, whatever. Off to the next fix-it.

as usual thanks for the help guys