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path1's avatar
path1
Explorer
Sep 02, 2015

A/C bolts question

Checked A/C today...

(Short version) Do the bolts that hold the A/C and gasket tight have any other purpose other than keeping a/c tight?


(Long version)Pulled A/C cover on inside to make sure a/c bolts were tight. They were not only tight but over tight IMO. Over tight, as in the heads of the bolts are pulling thru the lower alum bracket that they go thru.

I'm thinking about taking the bolts out and adding a washers, so that stress would be dissipated.

Just wanted to double check here to make sure bolts don't have any other purpose.

Thanks
  • I wouldn't touch it unless you have a new gasket ready. If you start replacing bolts, odds are you will break the seal and with the old one crushed, it likely won't reseal.
  • Hi,

    If your gasket is leaking, then time to replace it. If not leaking, leave well enough alone, and just install fender washers under all the bolts, one at a time, and it should be fine. Any leaks will just get the inside a little damp, and drip through the inside cover to the floor.

    To replace the gasket, you need to disconnect the 120 and 12 volt wires to the unit, place a thick blanket on the roof, and then loosen all the bolts. Move it over to the blanket (to protect the roof) and then replace the gasket. Transfer everything back to the top of the new gasket, and put back the wires / bolts.

    If you do not feel up to the task of moving everything, then for about $200 your local RV dealership can do it for you. The A/C is about 95 - 120 pounds. . . Yes it would take two people. .

    Good luck,

    Fred.
  • Somebody really cranked down on those bolts.

    The 4 corner bolts are to keep A/C Unit attached to roof and apply enough force to make roof gasket seal.

    Over tightening can warp roof, crush gasket and damage A/C pan.
    As you have found out. Wide washers will help keep already damaged area from more damage. New gasket as it has been crushed with hold down bolts that tight.

    Roof gasket should only be compressed to 1/2 of thickness. Hold down bolts are to be 'snug'....finger tighten then just slight snug up with wrench.
    If you have an 'Pound-INCH' torque wrench they are torqued to 20 pounds-inch

    Not 20 pounds-foot -----that would be like how tight you would tighten a 1/4" standard bolt using a box end wrench and hand cranking it tight.
    20 pound-inch is just a slight tweak after finger tight.


    NOW don't confuse the 'terminology'
    Pounds-Foot (pounds-inch) are measurements of 'torque'

    Foot-Pounds are a measurement of 'energy'

    Lots of folks will use 'foot-pounds' when talking about torque just like 'tank vs cylinder' for propane and think they are the same.......but they aren't.
  • Replace the A/C to roof gasket at the same time. The old one is probably crushed too much to ever seal again.
    Art.