Forum Discussion

sparkydave's avatar
sparkydave
Explorer
Aug 27, 2018

A/C gasket leaked

Fortunately, not much leaked. After a heavy rain Saturday, a slow drip came from one of the plastic screws that holds the filter screens on (Coleman Mach 3). After I got home, it appears the foam gasket has sagged, and the edges have gaps in them. New one on order.

Do these gaskets usually require regular replacement? I installed the A/C about 8 years ago, and the foam was very springy. Now whatever tension was holding the foam firmly against the roof is gone.
  • Roof Top A/C Units bounce/get jarred/vibrate from traveling down the road

    There are 4 'hold down' bolts that keep the unit up on roof

    They loosen over time and need to be tightened

    Remove ceiling grill cover and SNUG up on the 4 bolts

    SNUG (40 INCH Pounds)

    IF you over-tighten THEN you will need to replace roof gasket otherwise they last for very long time. (Mine is 12 yrs old and still doesn't leak)
    IF you over-tighten THEN you will block off the Evap Coil drip pan drain holes and condensation will leak inside RV
    IF you over-tighten you can warp RV roof causing puddles to accumulate

    SNUG ...
  • Tightening the bolts sounds like bad advice, they were tightened to compress the gasket to a specific spacing. Now that the foam has sagged, the unit is sitting too close to the roof and the bolts are loose. Sure, tightening them might help it seal again, but there's probably a good reason there's a plastic gauge to show the spacing from the roof, and the installation instructions were very specific on getting that height correct.

    I'll ask again, "Do these gaskets usually require regular replacement?".
  • sparkydave wrote:
    Tightening the bolts sounds like bad advice, they were tightened to compress the gasket to a specific spacing. Now that the foam has sagged, the unit is sitting too close to the roof and the bolts are loose. Sure, tightening them might help it seal again, but there's probably a good reason there's a plastic gauge to show the spacing from the roof, and the installation instructions were very specific on getting that height correct.

    I'll ask again, "Do these gaskets usually require regular replacement?".


    OK....don't check the hold-down bolts
    Buy new gasket
  • Old-Biscuit wrote:

    OK....don't check the hold-down bolts
    Buy new gasket


    OK, I will.

    "After I got home, it appears the foam gasket has sagged, and the edges have gaps in them. New one on order."
  • My first pup had ac, my second pup no way. I had many problems with mine freezing, bouncing, dripping, you name it.