Well, finally got around to getting the Extra Hvy Duty engine puller operational and even tho I knew the hydraulic bottle jack was questionable,,,IT don't jack up or down,,,,,

 It has like a two piece piston of several small pieces instead of the usual and customary straight piston with the seal at end of piston. I got some pics so maybe someone can ID that jack or know where to call to buy a kit. There is NO name on jack. There is some numbers on base right by the pump mechanism ,,,2-73. Also 511-7 on big nut on cylinder. On bottom of base is 1121-1001

  

I have 12-ton HW bottle jack that has that jointed piston.  I have looked for one and have about given up as the one I found so far, they wanted more for than I could buy a couple new off brand 12-ton jacks for.  Total for rebuild parts cost was looking like better than 3X the price of a new jack.  I would like to fix it, but it is one of those where you have to ask, is it worth it.  For now, I have 2 new 12-ton jacks to use. You might want to look at modifying a new jack to take its place.

   Yeah Tom and Jim,,thats kinda what I figured,,,I musta looked at several Million images of  bottle jacks and not find one that might come close to having the similar dual piston insides ,,,and after asking myself "If" it was such good idea,,,,why didn't it get copied???  My guess is this antique will find it's way to the junk pile and Joe will find his way to Harbor Freight.,,, Many THANKS for ya'lls efforts 

don't knock ALL 'Made in China' stuff. neighbour bought one of those 8T engine pulling hoist jacks from as he NEEDED it PDQ....We pulled a SBC350,let it up over night,still up next day. For giggles we left it there...days past...3 weeks+ STILL up high ! Only came down cause he sold the engine.

So SOME things from China are well made !

Guy gives me a 20T bottle jack ( N.D.GOOD.. scrap..). It was new, he used it all summer moving a barn,so outside in the hot sun... After 2-3 weeks of moving it here,there, everywhere, finally look at it. ADD some oil.been GREAT ever since. I'm thinking the hot sun on a black jack turn the oil into fumes and it vented away...

I remember years ago there were a couple guys that had repair businesses fixing jacks and air tools.   They came around every couple weeks to pick up things for repair and returned them to you on the next visit, cleaned, painted if needed and ready to go, for less than the cost of a replacement.  Same with the route salesmen for the auto parts stores. They picked things up, took them back to the store's shop, and returned them to you.  Many stores had their own shops and did engine work, relined clutches and brakes, speedometers, tachs, and proofmeters.  Those people/things are few and far between now, at least around here.

 Yeah Jim,,that sure looks like the piece I was looking for but like you say,,,$99.68 is too steep plus the rest of kit plus S&P,  is definitely too much when  you could buy 2 or maybe 3 new Jacks at HF for same money,,,,ole Shameless may call me Cheep all the time but I like to refer myself as Frugal,,, THanks for that link!

OH and just remembered a friend thaT has a tire shop just down the road was telling me that he used to have one of them traveling repair guys pick up his floor jacks, repair em and bring them back all ready to work until He could go the HF and buy brand new floor jacks for much less money than the repair guy was charging him,,,,,

I certainly won't say it couldn't be done.  I will say HW made a different 12-ton model that looks the similar that uses a straight solid pump piston.  However, I can't find any info they can be interchanged, and I am too "fugal" as Joe says to buy one just to find out they won't interchange.  I figure my risk of failure is less with the new HF jack.

 Hey Jim and Steve,,seeing as how very much I like to play with my lathe,,I may just try  to machine a one piece piston for the HW when I get bored with my other projects (I've always thought "Variety is the Spice of life",,,,

 As a fact of the matter, Thad, I DO have another engine puller and like your's had been at my friend's  field for  so long I had plumb forgot ,,sheeesh,,talk about "Friends",,,!! So, went over there and there it was,,,on it's side with the long travel cylinder removed and laying on the frame,,, SO,,careful to not say too much to my "EX Friend" for fear of landing in the county jail, I loaded it up and got it home,,,,,As I expected, the cylinder was froze up as he had pulled the packing out the top and then left it exposed to weathwer for a few years,,,,,!!!A-Hole,,,!! That puller is a light duty model made by either Autozone or Napa can't remember for sure and the extended forks are only 5 feet long where this big bruiser's extended forks are 6'10" long and the upper frame is 1/2" metal, where the btm frame is 3/8"  Ya'll know that "The younger we get ,,the more we remember," and just happened I had bought a nice 20 ton Duralast bottle jack at a yard sale a few years back,,SO I dug it out and still works like a charm, so I'm gonna use it as it ain't doing nobody no good under the cabinet in garage,,,!!