Announcement

Collapse
No announcement yet.

Enerpac P39 hand pump tear down, tool and Qs

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Enerpac P39 hand pump tear down, tool and Qs

    Right, this thing has been quietly leaking ever since I got it working a few years ago - I picked it and the Enerpac 10t benchtop press it was attached to from my uni as they didn't want to fix the blown piston seal. Replaced the seals in the piston and it was all good, until it gave up the ghost recently. Piston now extends and retracts with the hand pump, so something's off and it wasn't fluid level.

    Bought a seal kit and not much seems to add up, plus I can't get the check valve screw out. Also made a tool to get a retaining ring out, which I'm rather proud off.

    First - anyone taken one of these apart before? The piston seals consist of (from outside>in): one threaded ring, 4 stacked split rubber washers, another threaded ring, 4 what look like cork washers, then a forming ring at the very bottom. The seal kit included an o-ring and a teflon washer, plus one square of uncut cork and the parts list makes no mention of the 4 cork washers only the o-ring and teflon washer. Any ideas?

    cork washers



    forming ring

  • #2
    the 2nd threaded ring needed a pin spanner I didn't have, so i made one

    piece of scrap with a handy hole in one end turned to size and 2 holes drilled and tapped in the end


    screws threaded in and cut to length


    worked a treat!

    Comment


    • #3
      Second question. I can't get the check valve screw out - any tips?

      it's this one, near the front left foot


      I've scrapped off the paint around the screw, tried a few cycles of MAP torch heat/ freeze spray cool and then had a go with the impact screwdriver (the one you smack with a mallet). No joy, just an increasingly mangled screwdriver slot. Gave up before I screwed it up and dabbed some acetone:PS fluid on it as I heard that works well.

      More of the same tomorrow or...?

      I'd rather not have to make another one, but it shouldn't be too terrible if it has a standard thread. Might even be able to adapt a hex head or socket cap screw, man I hate slotted screws.

      Comment


      • #4
        swedish pattern pipe wrench. works good on stuff like that.
        san jose, ca. usa

        Comment


        • #5
          Sorry....obvious question. Enerpac customer service or service department has been of no help?

          Maybe Youtube?
          https://www.youtube.com/watch?v=Sq-Yrb39ucg

          Comment


          • #6
            I have the same pump with a Blackhawk logo on it.The washers you are holding are actually V-packing.

            http://www.veepacking.com/

            That metal ring is the the bottom male adapter and the spanner nut should have the top female adapter machined in it,or it takes a separate top female adapter ring.

            It may be that you have an older version of the P39 and the newer version takes the seals in the kit you bought.

            Oh,forgot to add,that relief valve screw IIRC has a copper seal ring.Mine required one hit from an impact screwdriver to break it loose.
            Last edited by wierdscience; 12-24-2016, 12:07 PM.
            I just need one more tool,just one!

            Comment


            • #7
              I rely extensively on a repair shop in Seattle for things like this. The place is amazing. Back in the '60s southwest Capitol Hill was essentially Seattle's Auto Row. There were tens if not dozens of repair shops. You could get leaf springs re-arced, your headliner recovered, new linings on your brake shoes or clutch plates, and many other things. There were also a lot of car dealers in the area. Back then I was a teenager who was into fixing things. A local gas station mechanic (widely worshiped by the local youth) told me to take something hydraulic down to this particular repair shop. I've been going there ever since. The auto stuff is nearly all gone now. Back then, they made a good living rebuilding stuff like floor jacks or pneumatic impact wrenches. Today they look just the same, and mostly it's the same guys working there, now old graybeards with infinite wisdom and experience. To first order they know everything about Enerpac stuff. If you lose faith, ship your pump to them and they'll rebuild it for you. They stock every part for a P39.

              Universal Repair Shop
              1611 Boylston Avenue
              Seattle, WA 98122
              (206) 322-2726
              http://www.d1060332-14740.customer.c...repairshop.net

              Hopefully you have the instruction and parts manuals, if not, post back or PM me.

              That stuck screw is worrisome. I might try heating the area and then using your impact screwdriver while it is hot, in case some numbnuts used thread locker.

              Worst case, used P39 pumps don't cost too much used. I had one I tried to flog for about a year with no luck, even at near giveaway prices. Nowadays people think Harbor Freight or Jet hydraulic stuff is the same quality as Enerpac, so aren't willing to pay for the latter.

              metalmagpie

              Comment


              • #8
                I had a bunch of those pumps apart before, Blackhawk is the same thing. Leather packings and the form ring.
                If I remember correctly there is a check ball in the piston well and two different size ones under that screw on the side I think the smaller one goes in first..
                There is also a small ball in the hole where the valve goes. Sometime when you take these things apart stuff falls out and then you have to figure out where it all goes. I had to make a couple different spanner wrenches for mine also. A lot of time a leaky seal can be cured just by tightening the spanner that presses the leather seals together. A lot of people tighten the outer spanner thinking that will cure it but that one is just a dust wiper.

                JL.................
                Last edited by JoeLee; 12-24-2016, 02:57 PM.

                Comment


                • #9
                  Originally posted by gambler View Post
                  swedish pattern pipe wrench. works good on stuff like that.
                  neat, never heard of one of those before not sure how it would have helped get that ring out, but it's something to bear in mind for the future!

                  Originally posted by reggie_obe View Post
                  Sorry....obvious question. Enerpac customer service or service department has been of no help?

                  Maybe Youtube?
                  https://www.youtube.com/watch?v=Sq-Yrb39ucg
                  not an obvious Q, hadn't thought to do that at all! I'll give 'em a call after Christmas, as well as the repair shop Metalmagpie mentioned.

                  nothing on youtube about tearing down a P39 unfortunately

                  Originally posted by wierdscience View Post
                  I have the same pump with a Blackhawk logo on it.The washers you are holding are actually V-packing.

                  http://www.veepacking.com/

                  That metal ring is the the bottom male adapter and the spanner nut should have the top female adapter machined in it,or it takes a separate top female adapter ring.

                  It may be that you have an older version of the P39 and the newer version takes the seals in the kit you bought.

                  Oh,forgot to add,that relief valve screw IIRC has a copper seal ring.Mine required one hit from an impact screwdriver to break it loose.
                  thanks! yep, that's exactly how it is - the spanner nut has a matching female recess in it. My guess is the same as yours, that it's a much older unit.

                  still no luck with the screw, even after another couple of heat/freeze cycles and a whack with the impact screwdriver.

                  Originally posted by metalmagpie View Post
                  To first order they know everything about Enerpac stuff. If you lose faith, ship your pump to them and they'll rebuild it for you. They stock every part for a P39.

                  Universal Repair Shop
                  1611 Boylston Avenue
                  Seattle, WA 98122
                  (206) 322-2726
                  http://www.d1060332-14740.customer.c...repairshop.net

                  Hopefully you have the instruction and parts manuals, if not, post back or PM me.

                  That stuck screw is worrisome. I might try heating the area and then using your impact screwdriver while it is hot, in case some numbnuts used thread locker.

                  Worst case, used P39 pumps don't cost too much used. I had one I tried to flog for about a year with no luck, even at near giveaway prices. Nowadays people think Harbor Freight or Jet hydraulic stuff is the same quality as Enerpac, so aren't willing to pay for the latter.

                  metalmagpie
                  thanks for tip, I'll definitely give them a call after Christmas. I have the instruction and part manuals, thanks.

                  yeah, I'm worried about that screw. I really don't want to have to use a LH drill to drill it out, but there's a good chance that one of the balls under it is causing the problem. I'll give it a few more days of acetone/PS fluid and heat/ freeze cycles. I'll try giving it a whack while it's hot too.

                  I'll keep my eyes open for a replacement pump, but I don't hold out much hope - tools are in short supply and vastly overpriced around here.

                  Originally posted by JoeLee View Post
                  I had a bunch of those pumps apart before, Blackhawk is the same thing. Leather packings and the form ring.
                  If I remember correctly there is a check ball in the piston well and two different size ones under that screw on the side I think the smaller one goes in first..
                  There is also a small ball in the hole where the valve goes. Sometime when you take these things apart stuff falls out and then you have to figure out where it all goes. I had to make a couple different spanner wrenches for mine also. A lot of time a leaky seal can be cured just by tightening the spanner that presses the leather seals together. A lot of people tighten the outer spanner thinking that will cure it but that one is just a dust wiper.

                  JL.................
                  thanks Joe. Yep, there's a spring and 2 different size balls under the screw I can't get out and a ball plus a couple of cork seals under the release valve.

                  good point about tightening up the collar against the v-pack seals. I did exactly what you said and tightened up the outer one before to no effect. Now I have the tool and the knowledge (sort of), I'll try snugging up the seals a little tighter before I look into replacements.

                  Comment


                  • #10
                    Try http://seattle.craigslist.org/see/tls/5932216359.html

                    Comment


                    • #11
                      Thanks, 9h+ round trip though I'm almost as far from Seattle as you can get and still be in Washington..

                      The photos did help remind me how to get the quick connect could off though, which was very helpful. You can forget about in 5 years!

                      Comment


                      • #12
                        finally got the check valve screw out. Not proud to say it, but I drilled it out. I used a small drill to make a pilot hole 1/2in or so deep, then a 1/4in left hand drill. After going about 3/8 of the way in the screw moved a bit. I could then tap it round with a punch and mallet.




                        I put it back temporarily by pressing a T40 torx bit into the hole, but I'll either buy or make a new one sometime soon

                        The copper washers under the screw were really mashed and I couldn't get the bottom one out, so I cut it out with a counterbore


                        then fished out the 2 balls and spring. The lower ball required a bunch of extra magnets to reach down far enough.


                        put it back together, refilled it and it sort of works. Goes down nicely, holds pressure but the ram doesn't want to retract either fast nor fully. I don't know if it was too cold in the garage (it was about 10-15F when I tried it) and the hydraulic jack oil was too viscous or if there was something I didn't do right. I did hold the hand pump above the cylinder while pumping/ opening it to get rid of any air in the system, but that didn't make any difference.

                        Well, at least it's mostly working now, which is better than not working at all!

                        Comment


                        • #13
                          If the ram doesn't retract one possibility is that you have too much fluid in the system. You might try removing a quarter cup or so and see if it goes farther. If not, you may have damage in your ram.

                          metalmagpie

                          Comment


                          • #14
                            good point, I hadn't thought of that. I did use the dipstick on the fill cap, but it would be easy enough to pour some out and see what effect it has. Grade of hydraulic fluid shouldn't have an effect, should it? The ram retraction is done by a spring in the ram. My wife just got me a quart of whatever jack fluid they had at HD.

                            Comment


                            • #15
                              Originally posted by mattthemuppet View Post
                              Grade of hydraulic fluid shouldn't have an effect, should it? ... My wife just got me a quart of whatever jack fluid they had at HD.
                              Maybe.

                              Perchance has an SAE wgt oil been used where an ISO wgt is specified?

                              .

                              Comment

                              Working...
                              X