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Seized Bolt Removal: Solutions

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  • Seized Bolt Removal: Solutions

    I recently broke the head off one of my rear subframe trunnion bolts. After soaking it in WD-40 and breaking an easy-out I decided it was time to call for help. Chuck suggested I pose the question of the best way to remove these stubborn bolts in other forums. I have posted some my findings here - hopefully these pieces of advice will help others.

    --------------------------------------------

    "The April/May 2007 edition of Machinist's Workshop did a test of penetrating oils where they measured the force required to loosen rusty test devices. Buy the issue if you want to see how they did the test. The results reported were interesting. The lower the number of pounds the better. Mighty interesting results for simple acetone and tranny fluid!"

    Penetrating oil . Average load .. Price per fluid ounce
    None .................. 516 pounds .
    WD-40 .............. 238 pounds ... $0.25
    PB Blaster ......... 214 pounds .. $0.35
    Liquid Wrench ... 127 pounds .. $0.21
    Kano Kroil ........ 106 pounds .. $0.75
    ATF-Acetone mix.. 53 pounds .. $0.10

    --------------------------------------------

    "What wound up working on mine was the application of penetrating oil, and then the repeated welding of a nut to the exposed end of the bolt. Each time the nut was welded on was an extreme heat cycle. The big benefit was that you could turn the bolt in a bit, then back it out a little more until the nut sheared off again. Frustrating but if you have a competent welder helping it does get the bolt out eventually.."

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    "We have bolted up the trunion and, using it as a guide, drilled the bolt (5/15") with not more than 7/32" bit and tap hole when last of bolt is removed.

    When restoring and using new heeel board or new heelboard ends, make sure the captive nuts are adequately welded and Never-Sieze the bolts."


    -Eric
    British eyes... only

  • #2
    No offense intended to you Eric or the other forums but here are my thoughts and experiences on penetrants and subframe bolts.

    The "scientifically rusted" bolts in the Machinist's Workshop test bear little resemblance to bolts and nuts that have been weathering on a car for 30 or 40 years. The acetone / transmission fluid mix is an ok penetrant and since it's cheap you can afford to have a quart or a gallon to drop rusted parts in for a few days. I suspect that the reason the acetone / transmission fluid mix had a low torque value is because it was the best lubricant not the best penetrant.

    Kroil and GM 1052627 Heat Valve Lubricant are two penetrants that I have used for almost 30 years and they have worked on bolts that haven't moved for as long as I have been alive.

    On most Mini bodyshells there are holes in the sill near the heel board that will allow you to spray penetrant on the captive nuts. You're spraying blindly, so you have to spray a lot but it does help.

    When welding a nut on to a broken bolt multiple heat cycles aren't generally needed. The nut breaking off is usually because there either wasn't enough current (heat) being used on the MIG welder or there wasn't enough bolt left to attach the nut to. If you're careful with the MIG welder you can build up the broken end of the bolt so that there is enough material to overlap the inside of the nut. This will make a much stronger weld. Once the bolt starts to move additional heat doesn't really help, at this point you're just working against the rust in the threads. This is a good time to use the cheap penetrant.

    Cheers,

    Kelley
    If you can afford the car, you can afford the manual...

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    • #3
      Thanks for the info Kelley. Do you happen to know where I might be able to pick up some Kroil around here?
      British eyes... only

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      • #4
        I can't remember how I found mine. Think I searched on line, or I stumbled onto it at my favorite nut and bolt shop. I use Kroil sparingly and only on those jobs where the part better not break...like those horrible rear subframe bolts.
        The more I know about Minis, the more I know I don't know about Minis.

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        • #5
          I believe Tacoma screw products has Kroil.

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          • #6
            I buy Kroil at garage sales, not very helpful is it? The GM Heat Valve Lubricant is available at most parts desks at GM/Chevy dealers. I use the GM stuff more than Kroil but if one doesn't seem to be working very well I'll try the other.

            Kelley
            If you can afford the car, you can afford the manual...

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            • #7
              From an uncle who restored Model T's - Mix equal parts stove oil or diesel and Type "F" (Ford) automatic transmission fluid in a squirt bottle (like restaurant ketchup bottle). Not sure why it is Type F, I think it has to do with more friction additive in it. (Lot less flammable than Acetone too.)

              A little heat, followed by a Big Ford Hammer tapping downward on the bolt head while it is cooling. While it is still warm enough you just about can't touch it. Squirt the diesel/ATF on it. If you get smoke it was probably too hot. I've used this to cold soak frozen nuts/bolts, takes a little longer.

              Sounds like a good candidate for anti-seize on reassembly.
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              • #8
                Found Kroil at Tacoma Screw. Thanks, that's a great store!

                Also found a great deal on it here:

                2 King sized cans delivered for $12
                http://www.kanolabs.com/HF-Deal/

                I didn't want to wait, so I paid $13 for 1-10oz can at TS.
                Last edited by 4BritishEyesOnly; 05-14-2010, 08:55 AM.
                British eyes... only

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                • #9
                  This is a great thread, thanks for the tips.

                  I find careful use of the proper profanity after the nut breaks, combined with an angry dance, and sometimes hurling tools works well, But that's just me.

                  I'm all for getting the mini owner bulk discount for Kroil.

                  Greg

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                  • #10
                    Used to hurl tools in fits of rage. Until I watched a coworker take a half inch ratchet, extension and socket in the mouth. After bouncing them off the concrete floor taking out three top front teeth, chipping a few others. Instant Billy Bob Teef! His gurlfriend wus real impressed when she seen him wif his new grill work!

                    Worst part, he had to lie to get workman's comp to cover his significant dental work.
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