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weird coolant leak?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Sparky, Feb 17, 2001.

  1. Sparky

    Sparky 1/2 ton status

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    For the past week i have been noticeing the smell of coolant after i drive my truck, but was not able to locate a leak. Today i was finaly able to notice where it was comeing from. The leak appears to be comeing out where the head meets the block, in the front, on the passenger side. I rebuilt the top end of my 350 a couple of months ago, and it was leak free until recently. When I did that i used Felpro metal gaskets and a even amount of copper coat. It has not overheated at all. I was thinking it might be comeing up through the threads on one of the head bolts, but the leak is comeing out just below the head, not at the bolts, and i used lock tite on them also. Does anyone know of any coolant pasage plugs in that area? It is just above the engine mount. If it is infact leaking out from the head gasket, do you think anything like "Bars" leak stop will work? Right now the leak is not fast. Only about a drip every couple of seconds untill it cools down. All suggestions are appreciated. Please help so i dont have to waste my spring break redoing a head gasket. Thanks.

    Sparky

    When all else fails... Check the blinker fluid.
    78 K-5
     
  2. wayne

    wayne 3/4 ton status

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    By the sound of it you might have a head gasket going south. I would not reccomend using a sealer on head gaskets. Thats just my 2 cents worth.

    Happy Trails
    Wayne
     
  3. Sparky

    Sparky 1/2 ton status

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    What do you mean by a sealer? I used "copper coat" on the head gaskets when i put it together, but everyone I have ever talked to suggests that for metal head gaskets. Bars leak stop is an additive you put into the radiator to seal up any leaks. If you were talking about that, why dont you recomend it? If it does not work I have not lost anything right? Let me know. Thanks.

    Sparky

    When all else fails... Check the blinker fluid.
    78 K-5
     
  4. Wallyb

    Wallyb Registered Member

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    I've used bars leak on a couple of vehicles and it has worked, but have been told that it's hard on the heater core, plugs it up I guess.
     
  5. Smitty

    Smitty 1/2 ton status

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    I've always only recommended stop-leak additives as a temporary measure. It might stop the leak but it's something just waiting to go wrong and it'll start leaking at the worst time. If I'm stuck with using a metal gasket it does get a spray coat of Coppercoat before everything goes together. I try to stay away from the metal head gaskets. Kind of partial to the Fel-Pro Perma-Torque gaskets. They seem to hold up and you don't need to retorque them.

    Smitty
     
  6. bablazer73

    bablazer73 1/2 ton status

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    Its very possable that it's coming from a head bolt. all the head bolts go into the water jacket. I use permatex aviation sealant on headbolts when installing them. If your good and carfull, you might be able to pull bolts out 1 at a time and reseal them.

    your right. I don't understand the jeep thing!
     
  7. jimmyjack

    jimmyjack 1/2 ton status

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    I used copper coat once before and ended up with a head gasket leakleak. I heard that sometimes it will get a "blem" ie a fingerprint, a wrinkle, smudge that won't let it seat smoothly. I was told to use a thin film of grease on the head, block and both sides of the gaskets AND the bolts. It squeezes out evenly when its torqued down. I've done it on 3 different engines, even with the perma torque gaskets and never have had a leak. Good Luck.

    creepin' and crawlin'

    Jim
     
  8. blazercrazy

    blazercrazy Registered Member

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    I have better luck without any sealant on the gaskets

    Make sure your truck is the muddy one! [​IMG]
     
  9. DMK

    DMK 1/2 ton status

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    I was always told not to use anything on head gaskets or any other metal gaskets. My 57 buick uses metal gaskets at intake, head, and oil filter adapter used no sealer and have no leaks.
     
  10. HarryH3

    HarryH3 1 ton status Author

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    If you're lucky, the Loc-Tite is your problem. You really need to use a sealant, not a thread locker, on the head bolts. I used the Permatex Aviation Sealer mentioned above on mine. It's really gooey, sticky black stuff that never hardens, so it seals VERY well. Without the sealant, coolant will wick its way up the bolt threads and come out wherever it can find an exit.

    I'd try removing just one head bolt at a time, apply sealant to the threads and retorque the bolt properly. Do them in the same order as the head bolt tightening sequence. Be sure you drain ALL the coolant from the engine before you begin by pulling the plugs on the side of the block.

    Of course, the proper way to do it would be to pull the heads, replace the gaskets, seal the bolts and reinstall everything. NOT my idea of a fun afternoon! [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
     
  11. Stoopalini

    Stoopalini 1/2 ton status

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    I will never use any form of stop-leak additive ever again! I used it in a car I once owned and everything seems fine ....... until a few years down the road when the water pump went out, hoses started rotting, thermostat got stuck, etc, etc, etc.

    The stop leak will stay in your system pretty much for life. It is designed to seal any small hole/space in the system. it will gunk up your thermostat and water pump too and I can only imagine what it does to the water channels in the engine.

    Does the leak drip when the engine is running? or only after you shut it off? I had an issue with a coolant leak that only appeared after I turned my engine off. It turned out to be a stuck thermostat that wasn't letting the pressure even out within the system.

    Just athought ......... Good Luck,

    Thomas.

    -- '84 K5 Blazer --
    <A target="_blank" HREF=http://Stoopalini.coloradok5.com>http://Stoopalini.coloradok5.com</A>
     

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