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470 head re torque - coolant release

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  • 470 head re torque - coolant release

    evening all.

    i jist re torqued the head on my 470 according to the manual and this post

    https://forums.iboats.com/forum/engi...-torquing-head


    I ran the engine is a full operating temperature and then allowed to cool. I then sequentially released each bolt and re torqued one at a time as per the sequence.

    I noticed that when I am dead two or three of the bolts a small amount of coolant escape from the bolt.

    is this normal or should I be worried ?



    thanks in advance

    ron

  • #2
    Did you put sealant on the bolt threads when you installed them? If not that is why they are leaking. The bolts would need to be removed and sealant applied, Permatex aviation sealant will work. You should drain enough coolant so that there is none in the head and make sure the threaded holes in the block are dry (you don’t want coolant in any blind holes when you put the bolts back in. You might be able to get away with only resealing the leaky bolts, but all should be loosened and retorqued in the proper sequence.
    Terry
    87, 4WINNS H 190
    470/Alpha I

    Comment


    • #3
      Thanks Terry, if I recall correctly I used perfect seal when I installed them yes.

      so long as I don’t have to pull the head again re dealing is not too bad.

      maybe I didn’t use enough perfect seal ?

      Comment


      • #4
        Jist to clarify - do the bolts enter the water jacket ? Is that where the coolant is coming from ?

        Comment


        • #5
          Some of the threaded holes in the block are open to the water jacket at the bottom, so unless you put sealant on the threads, water will weep up passed the threads, especially as it's a closed system and works under pressure when the engine is warm.

          Chris.......
          xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
          The world takes on a whole new perspective when viewed from 100’ below.
          1972 Bertram ‘Bahia Mar’ 20
          2006 Mercruiser 4.3MPI (0W617679) w/Alpha One Gen II (0W829301)
          (Original - 1972 '165' In-line 6. Previous - 1994 4.3LX)


          Comment


          • #6
            Thanks Chris that explains why only two bolts did it. They were both on cyl 2.

            i did use perfect seal but maybe not enough.

            now that they are fully torqued would I be ok leaving them as is or better to perform the retorque in sequence and add more sealant ?

            besring in mind that access to the threads in the block is going to be restricted for cleaning by the head still being in place ?

            Comment


            • #7
              Permatex Aviation sealant on the bolt thread
              NO PERSONAL QUESTIONS, THIS IS WHAT THE FORUM IS FOR.

              Comment


              • #8
                Personally, I would warm the engine, then drain out the coolant until it's below the level of the head and then just remove each bolt, one at a time, and put sealant on the threads and under the bolt head (as per the manual) and re-tighten it to spec.... Refill the coolant and forget about it...

                I realise you can't clean the threads in the bock with the head in place, but as they were cleaned before you put the head on (weren't they ) and I would think that as it's not so long ago you should be fine.

                Chris.......
                xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
                The world takes on a whole new perspective when viewed from 100’ below.
                1972 Bertram ‘Bahia Mar’ 20
                2006 Mercruiser 4.3MPI (0W617679) w/Alpha One Gen II (0W829301)
                (Original - 1972 '165' In-line 6. Previous - 1994 4.3LX)


                Comment


                • #9
                  Thanks both. I have permatex as well as perfect seal.

                  i have a week of decent weather ahead so will do as suggested despite having put perfect seals on the underside of the hex flanges initially.

                  Comment


                  • #10
                    Just thinking out loud here if the engine was still warm enough for the coolant to be pressurised could it have pushed past the threads when I undergone in order to re-tighten them ?

                    Comment


                    • #11
                      Quick question - is there any reason I can’t just re seal and torque the offending bolts or do it have to do all of them in sequence ?

                      Comment


                      • #12
                        Doing just the 'offending bolts' should be fine..
                        xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
                        The world takes on a whole new perspective when viewed from 100’ below.
                        1972 Bertram ‘Bahia Mar’ 20
                        2006 Mercruiser 4.3MPI (0W617679) w/Alpha One Gen II (0W829301)
                        (Original - 1972 '165' In-line 6. Previous - 1994 4.3LX)


                        Comment


                        • #13
                          Did them today and found little or no sealer on the threads but lots in the shaft showing that I did use it initially

                          pics attached

                          Comment


                          • #14
                            I like to use black RTV or permatex #3. I coat the threads, wipe with my fingers so only the valleys of the threads are filled, wait 10 minutes then install the bolts.
                            Cheesehead boating the Gulf Coast of FLA 27.51° N, 82.53° W

                            1988 Cruisers Rogue 2420 -VP 290 DP now powered by custom 468 - https://forums.iboats.com/forum/owner...988-rogue-2420

                            Past Boats
                            1970 Wooster Hellion - Merc 9.8
                            2002 SeaRay 190BR - 5.0 - A1G2 - "Cheeseheads in Paradise"
                            1984 Avanti 170DLI -3.0 stringer- "Ship Happens"

                            What’s behind you doesn’t matter.Enzo Ferrari

                            Comment


                            • #15
                              Sign up today
                              You tacked onto an old thread. I parsed your post off and started a new topic for you.... (Yeah, I'm nice... )

                              In answer to your questions. Yes.
                              It's recommended, to avoid exactly this situation, that you depressurize the cooling system (VERY carefully!) before re-torquing head bolts (due to the very nature of having to loosen them off first)....

                              Chris........
                              xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
                              The world takes on a whole new perspective when viewed from 100’ below.
                              1972 Bertram ‘Bahia Mar’ 20
                              2006 Mercruiser 4.3MPI (0W617679) w/Alpha One Gen II (0W829301)
                              (Original - 1972 '165' In-line 6. Previous - 1994 4.3LX)


                              Comment

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