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  1. #1
    Join Date
    Aug 2009
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    Sydney, NSW, Australia
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    Default Anyone got a idea on a DIY press?

    I have been working on a jetski motor which took on water and hydro locked it was than stored for 4 weeks, i have it torn down but i am having difficulty removing 2 rusty piston pins, last night i bought a 6 ton shop press but unfortunately the piston cant reach out far enough to fit in the press plus trying to lift the jetskis motor up to the press height is difficult as its heavy

    i seen a guy on youtube use a huge industrial C clamp with a huge impact drive bolt to drive a piston pin out does anyone have a idea of a basic press that will work? something i can build needs to handle my pneumatic impact wrench 400ft/lb

  2. #2
    Join Date
    Jun 2007
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    I normally soaked in the the 50/50 Autotran fluid+ acetone for awhile then put a bit of heat on it seems to work. This badly seized 60 years old piston came apart with the same method.

    20180203_120203.jpg

    20180203_131148.jpg

    20180203_131754.jpg

  3. #3
    Join Date
    Oct 2004
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    Southern Highlands NSW
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    1,894

    Default

    I've heard of someone using an hydraulic fitting in the spark plug thread, and using a press pump to loosen a stuck piston.
    No good if the ports are open though.

  4. #4
    Join Date
    Apr 2012
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    Healesville
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    If it is the gudgeon pins that you are talking about removing then you should be able to make yourself a puller with a long bolt through the centre of the gudgeon pin and suitable spacer for it to slide into as the gudgeon pin is extracted when the bolt is tightened.

  5. #5
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    this worked for me too if you don't need to save the piston.
    20170212_143956.jpg

    20170212_155327.jpg

  6. #6
    Join Date
    Jan 2004
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    Mackay North Qld
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    Default

    Quote Originally Posted by gazza2009au View Post
    I am having difficulty removing 2 rusty piston pins,

    Without a pic to guide us it pretty hard to imagine the configuration for those of us who have not seen a stripped down jet ski motor.
    We will assume you are trying to save the pistons.

    I googled and came up with this pic from which you could scale to the dimensions required.

    It is not too hard or too expensive to make assuming it can fit under the area of the barrel skirts.

    I would guess some 25 x 5 x3 flat, some 25 x 10 bar, some threaded bar and nuts and some taps to suit, should see you through if it fits in the assembly.

    Grahame

    Gudgeon pin pusher.jpg

  7. #7
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    Default

    Sorry I didn't read your post probably. How about something like this?

    20160529_192414.jpg

    20160530_210224.jpg

  8. #8
    Join Date
    Oct 2007
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    Sydney
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    Default

    Surely you would be removing the piston anyway and then the gudgeon pin can be pressed out?

  9. #9
    Join Date
    Aug 2009
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    Sydney, NSW, Australia
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    Default

    Here are the pics thanks for the help so far guys i appreciate it, the bottom half of the motor is now sitting in the shed so i can work on it, what is stuck is the pin that goes thru the piston this is a floating pin meaning it just pushes in with your finger there is also a needle bearing inside of this piston on the conrod this bearing is rusted from the salt water that entered the motor now since the bearing is rusted this is what is seizing it all together

    so far i tried the whole bolt to press out the pin i was using one of those 12volt impact wrenches for car wheel nuts the pin moved all of 1mm so i think i need the big guns my 400ft/lb pneumatic impact gun and some sort of pin pusher

    i already have the cylinders removed i had to set up a press to press them off
    Attached Images Attached Images

  10. #10
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    Default

    since the piston is gone, cut it open to expose the pin, that would make it easier to get to the wrist pin itself?

    20170212_155425.jpg

  11. #11
    Join Date
    Aug 2009
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    Default

    Here are some bit better pictures showing all the positions i can move the conrods in i need a smallish press but it needs to be super strong to withstand the full 400ft/lb of torque from the rattle gun i think the press and rattle gun is my only option as not to bend the conrods if i were to use a breaker bar on the press

    one picture shows up the piston skirt and it shows the seized rusty piston pin and needle bearing, since this motor was hydro locked its possible those piston pins are bent hence they are taking a crap load of force to move
    Attached Images Attached Images

  12. #12
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    Quote Originally Posted by jackaroo View Post
    since the piston is gone, cut it open to expose the pin, that would make it easier to get to the wrist pin itself?

    20170212_155425.jpg
    Jack i thought about doing that it would be the lease work involved but it would be delicate if i was to nick the conrod i may as well just cut it in half, how did u approach your piston with the grinder?

  13. #13
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    Apr 2012
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    Default

    I would be patient and soak them for a week or so.
    Chances are that you are gunna need new rods because of the pitting in the small end, crank pins likely also.
    I reckon you should be able to get them out with a bolt and some spacers tho, without the need for a rattle gun

  14. #14
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    It was a drastic decision but u chose the grinder over 2 hours making a press the heat from the grinder helped a lot in freeing up the stiffness, the first piston i cut in a manner where i kept the cutting disc away from the conrod it took around 10-15 cuts than it peeled away the second piston i realised i could just do one long successful cut from side-top-side than wiggle each half back and forth it came loose

    after i had the first piston off i realized the conrods were cactus so i just lightly hammered out the pin and bearings, i don't think the little end of the conrods can be honed but the bearings were not overly rusted either so i'll drop the crankshaft into a specialist and see what old mate says

    so now its done no press were needed but i would still like one of those big heavy duty C clamp presses for future use
    Attached Images Attached Images

  15. #15
    Join Date
    Nov 2008
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    North Brisbane. Qld. Australia
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    70
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    Default

    Have a look on eBay etc for Ball Joint Press Tool.

    I have this type which I bought to do Ford ball joints on my niece's car. The C clamp needed a bit of work to true up the faces though. Only used it the once so far but should work on other things. Got it for $90 IIRC.

    https://www.ebay.com.au/itm/21-pc-Un...4AAOSwN2VZTRA1
    Nev.

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