Home Forum Ask A Member Distorted/leaking thermostat covers

Viewing 10 posts - 1 through 10 (of 15 total)
  • Author
    Posts
  • #1464
    johnyrude200
    Participant

      I have been running into a lot of these situations, but of course don’t find out until after I’ve replaced the thermostat and gasket, only to see water start gushing out of the 0.5mm gap.

      Any recommendations/tips to help reuse the same cover. I have been seeing many of them distorted and try sanding/lapping them down, but that doesn’t seem to work very well.

      #15731
      chinewalker
      Participant

        US Member

        Double up the gaskets?

        #15732
        chris-p
        Participant

          Any particular motor? Are you using gasket sealing compound? As stated, worst case, double em up.

          #15733
          legendre
          Participant
            quote johnyrude200:

            I have been seeing many of them distorted and try sanding/lapping them down, but that doesn’t seem to work very well.

            Are these housings steel stampings or aluminum / zinc castings? Warped steel can be a headache, trying to re-form a precision surface.

            But if they’re cast, then you must have some flaw in your lapping process. Either you’re not going far enough, and they still have excessive warping – or a flaw in your tools / technique isn’t producing the desired flat and uniform surface.

            As you’re lapping, do you follow your progress, checking with feeler gauges?

            #15745
            Mumbles
            Participant

              This problem is common with the three bolt cast aluminum housings. Since they can’t be lapped or machined because of a protrusion on them, I have resorted to mounting them in the press and VERY LIGHTLY apply some pressure to coax them back to their original shape. Being cast, they will break in a heart beat so light pressure is the key here.

              #15749
              johnyrude200
              Participant

                Thanks Mumbles, they seem to be common on the 6, 10, and 18-20-25 thermostat covers. They distort at the ‘thin’ side (starboard side), and those 3 screws really don’t do that great of a job of tightening the cover down.

                Legendre – I am using a straight edge and holding it across the surface of the cover to see where the warp is. Just one of those deals that when you disturb something that has been set for 40 years, you trigger 3 other issues in the process. Better me I guess than the next guy.

                #15750
                legendre
                Participant
                  quote Mumbles:

                  This problem is common with the three bolt cast aluminum housings. Since they can’t be lapped or machined because of a protrusion on them (…)

                  You can’t even mill them true? How was it done at the factory?

                  Could someone please provide a photo or drawing of this part, I’m curious what feature prevents a straightforward lapping..?

                  #15753
                  Mumbles
                  Participant

                    #15782
                    david-bartlett
                    Participant

                      I have seen this where people store their motor lying down in freezing temps. A bit of left over water can freeze and cause the cover to deform. Another good reason not to lie the motors down during unheated storage.

                      #15785
                      dan-in-tn
                      Participant

                        US Member

                        The way I remember this working is the part sticking out of the casting holds the thermostat down in place. The OEM gasket is already very thick. Doubling the gasket makes the thermostat loose and leaky. Now if you are removing the thermostat then it doesn’t matter, but that is another discussion. Removing material around the outside surface only will make the casting dig into the thermostat and warp it at the screws. Just something else to think about when you are dealing with this irritating part.

                        Dan in TN

                      Viewing 10 posts - 1 through 10 (of 15 total)
                      • You must be logged in to reply to this topic.