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Head Gasket Replacement Advice

Discussion in '40- & 55-Series Tech' started by Rick '79 FJ40, Feb 23, 2007.

  1. Rick '79 FJ40

    Rick '79 FJ40 SILVER Star

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    I am pretty sure my '79 FJ40 has blown a head gasket. I have been noticing that a little coolant has been disappearing for a while, but could see no evidence on the plugs. I also noticed that I got some white smoke/steam out the pipe when I first cranked it up in the morning. It was running great until last weekend when I cranked it after sitting for a couple of weeks. It was running rough and didn't get much better after warming up. I drove it about 15 minutes and it got where it was idling rough so I took it back home. I haven't looked at the oil yet, but I'm pretty sure it will have water in it.

    I have searched the threads on here, but I haven't found one that has all of the info that I am looking for. Mainly, is there a kit of gaskets that Toyota sells that has everything I need for doing the job, or do I need to assemble all of the gaskets individually? If the latter, what gaskets do I need besides the head gasket?

    I assume I need:
    Head Gasket
    Manifold Gasket
    Water Pump Gasket
    Thermostat Housing Gasket
    Valve Cover Gasket

    But what about:
    Timing Cover Gasket
    Side Plate Gasket
    Anything else?

    I would also like to get advice on what would be good to do while I have the head off. I have heard to do a valve job, obvioulsy clean up the head and have it checked (magnafluxed?) for cracks, maybe decked?

    I was told that I might need to do a ring job and hone the cylindrers so that the improved compression from the valve job doesn't cause ring blow-by. Is this doable without taking the engine out? I assume I would have to drop the pan, so I'd need a new pan gasket. Would this be a good time to replace the rod bearings? And is there anything else that would be a good idea to replace? Push Rods? Valves? Valve guides? Oil pump?

    My goal is to do the least work necessary, while getting the most bang for the buck. I don't want to have to do anything like this again in the near future, and I want my truc to be as reliable as possible (obviously).

    If anyone has a writeup on this, hopefully with pictures,I would really appreciate a link.

    Thanks for any help you guys can give me!
     
  2. KLF

    KLF Frame waxer SILVER Star

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    Only advice I can provide:

    I would never start on such an ambitous project without doing a leak-down test first. It would be like going into open heart surgery without even taking your blood pressure reading first. You may find that the HG is not leaking at all. Or there may be something else wrong that you should fix at the same time, such as excessive ring blow-by.

    Just something to consider...
     
  3. Rick '79 FJ40

    Rick '79 FJ40 SILVER Star

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    Thanks for the advice. I plan to do a lot more checking, I just wante dto start the information gathering process as soon as possible so I know what I am looking at if I find I need to do it. I figure, even if I don't need to do it, it doesn't hurt to learn as much as you can.

    Thanks!
     
  4. Buckwheat

    Buckwheat

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    Leak down

    tests the cylinders for integrity. Are you sure you're not referring to a cooling system pressure test? If you're losing water, that is the place to start. Blown head gaskets usually cause overheating, so if that ain't happening, it could be a crack. You could have a cracked head which just pisses a little water into the cylinder when cold & more when hot, or you could have nothing - water does evaporate over time. The white smoke you need to worry about is when you have clouds of it out your tailpipe, not a minor amount on startup. That is condensation burning off. Don't assume the worst. Thoroughly diagnose the problem before starting, like the man said, on a head gasket job. If you got a misfire, figure out what's causing it first! The engine can be overhauled in the vehicle & gaskets come in head sets, overhaul sets, however you want them. :cool:
     
  5. KLF

    KLF Frame waxer SILVER Star

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    Nope, I mean a leakdown test. A coolant pressure test won't always find a leaking HG, sometimes it take more pressure to detect a leak.

    Not always. I've repaired several blown HGs that never overheated. The 22RE in my son's 4Runner had coolant pouring down the side of the block, but never once ran hot. A friend's Subaru was eating coolant, but ran fine. But as soon as I put the leakdown tester on #3 cylinder and hit the pressure, coolant geysered out the radiator. Neither smoked a bit either.

    Bingo.

    Rick: good of you to learn as much as you can before tearing in. I remember languishing over spending the $50 on a leakdown tester, I figured I'd only use it once, it would be a waste of money. I think I've since used it 6-8 times, very handy tool. Maybe get a buddy to split the cost so it doesn't hurt as bad.
     
  6. grant5127

    grant5127

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    you need to broaden your spectrum........:idea:
     
  7. Rick '79 FJ40

    Rick '79 FJ40 SILVER Star

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    I have a compression tester, what is the difference between a leakdown tester and a compression tester?

    Thanks for the help!
     
  8. grant5127

    grant5127

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