Jinma 385 head gasket repair

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    • August 19, 2013 at 11:25 am #30804
      donaldl
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        Gentlemen;Added a pint of water to my cooling system last month.Then sent a sample of my oil to Blackstone Labs for analysis.They called to warn me that there was atifreeze in the sample,(they have great customer service).

          So I made a leak down tester out of an old glow plug and pressure tested all three cylinders.The middle cylinder is leaking to the water jacket and front cylinder.

        When I pull the head; can I remove any material from the surface if I have to?

        Should I use new head bolts?

        Checked another post and they don't recommend copper head gasket spray.

        Can anybody tell me why ?

        Anything else I might need to know?

                                                                 Thanks, Don L.

      • August 19, 2013 at 2:06 pm #36331
        Affordable
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          Did you purchase the tractor new ? Did you do a head re-torque at 50 hours ?

           

          Most of the time that's what the problem is, you can have the head ground some if needed,

           

          Tommy

          Affordable Tractor Sales

          “Your Jinma Parts Superstore”

          http://www.affordabletractorsalesco.com

        • August 19, 2013 at 4:45 pm #36332
          RichWaugh
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            Just so you don't get confused, what Tommy said shouldn't be interpreted to mean that you can just go in and re-torque your existing head gasket and be okay – you can't.  It needs to be replaced with a new one.  And then you do need to do are-torque and valve lash adjustment at 50 hours.

            There is no need for any gasket compound with most modern head gaskets and it is easy to gook up things with too much of the stuff so I recommend not using any.  In the way old days, copper compound was good for conducting heat away form the head on flathead engines, but these days they use water jackets.  (grin)

            Unless your head is more than .005″ out of planar, I'd just put it back on with a new gasket.

          • August 19, 2013 at 6:33 pm #36333
            Bob Rooks
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              I'm glad to see someone else using oil analysis too.

              The minimal cost is easily justified.

              Account deleted.

            • August 20, 2013 at 10:56 am #36334
              donaldl
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                Gentlemen;Thanks for all the responses.

                    The oil analysis had paid for itself  with my 2010 truck as it allows me to have less oil  and filter changes .

                  Hopefully it will have been used early enough  in this situation with my tractor.

                                                                                     Don L.

              • August 20, 2013 at 7:44 pm #36335
                DavidPrivett
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                  I think that the reusal of the cylinder head bolts would be ok ,no difference that I know of reusing the head bolts than retorqueing the head. If there is any hard junk on them I would be careful and run a tap in the block and a die on the bolts,but make sure that when you do this that there is no unusal amount of metal being taken off.Stop if there is,some difference in thread pitching I have seen.Though mostly threads are cut to loose.

                • August 23, 2013 at 2:26 pm #36338
                  donaldl
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                    Mr.Privett;  I did find the rear left head bolt galled.I recontoured the treads on the bolt to an angle and tapped that bolts original hole to allow for” finger tightness”.Only three threads are involved so I hope that will suffice.Don

                  • August 28, 2013 at 6:13 pm #36351
                    DavidPrivett
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                      if possible use a bottom tap instead of a taper tap ,I assume that the effected threads were at the end of the bolt placing the problem at the bottom of the hole.also check the hole depth maybe the bolt is bottoming out.

                    • August 29, 2013 at 4:07 pm #36352
                      donaldl
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                        Mr.Privett;That galled bolt was located in the same hole the rear head indexing sleeve is in (the sleeve helps align the installation of the head). Both the front and rear sleeve were “self tapped ” because they were slightly smaller than threads on the bolts.I cleaned those sleeves of all roughness but did not have the “bottom tap” that you recommended.

                           The bolt did take the 105 torque recommendation with good feel.I will let the forum know if the status changes on the 50 hour retorque. Don L

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