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Hydraulic starter on GM Detroit diesel?

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  • Hydraulic starter on GM Detroit diesel?

    I have to go & look at a pumping set tomorrow, which I think has a 3-cyl series 71 or similar 2-stroke diesel.
    The starter is a hydraulic motor which fits in the place of an electric starter motor, run from a hand pump and reservoir, probably with a gas spring. Apparently this starter has jammed in some way, the system is pressurised but it won't work.
    I'm not at all familiar with this type, anyone here ever met them & have any tips?

    Thanks

    Tim

  • #2
    I can remember pumping the hell out of them then tripping the start lever, which sometimes was pretty hard to do and if you pumped enough it would spin over. Does the start lever seem to work?

    John
    My Web Site

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    • #3
      No experience, but I had a browse round at the mention of hydraulic starters wondering if it'd be a viable alternative for my dragbike (it wont, too heavy and extra fluids etc) and found this site, the layout at the bottom suggests the symptoms could be a result of a non functioning control valve :-

      http://hydraulicspneumatics.com/othe...rs-high-torque

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      • #4
        Sorry Tim no direct experience with hydraulic starters, lots with air air starters but that's no help here.

        Here are some links though that may give you some insight into the system, one is a video.

        http://constructioncranes.tpub.com/T...14-P-30045.htm

        http://www.youtube.com/watch?v=jEo7ySCIjJ4

        Can you relieve the system pressure in order to diagnose the "jam", in order to see if perhaps it is a physical blockage in the hydraulic system or the starter motor itself?
        Home, down in the valley behind the Red Angus
        Bad Decisions Make Good Stories​

        Location: British Columbia

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        • #5
          MrFluffy: Hmmm, Drag bike you say?
          Well, a few thoughts come to mind.

          First off, you got a nice pool of 'Not so hydraulic' OIL siting in your motor that might be usable.. probley ruin the seals though. Sure wouldn't hurt to have high oil pressure during startup though.

          Other thoughts are if its a drag bike, can you have external systems? Two quick connects to an external powerpack... of course, then you might as well make a physical quick coupler and have the whole hydraulic starter removable.
          Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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          • #6
            I know from experience that pumping one up by hand will give you a sure enough workout. I used to help unload barges with that pumping system. Sometimes the pressure built by the engine pump would have leaked off, two or three of us would have to take turns on the hand pump to get enough pressure to start the engine.
            Jim

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            • #7
              J harp: Small (chainsaw? lawnmower?) motor + hydraulic pump = Easy starts?
              Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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              • #8
                I'm very familiar with the Berger 'Handraulic' starter which does the same job but rather differently. They use a pair of opposed cylinders with racks working on the end of the engine crankshaft.

                http://www.atlanticdiesel.com/emergency-starting.htm

                I've never dealt with a hydraulic motor starter though.

                Tim

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                • #9
                  Black_Moons; Wouldn't want to use those on a barge load of gasoline, "kaboom" chance too high.
                  Jim

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                  • #10
                    Originally posted by Timleech View Post
                    I have to go & look at a pumping set tomorrow, which I think has a 3-cyl series 71 or similar 2-stroke diesel.
                    The starter is a hydraulic motor which fits in the place of an electric starter motor, run from a hand pump and reservoir, probably with a gas spring. Apparently this starter has jammed in some way, the system is pressurised but it won't work.
                    I'm not at all familiar with this type, anyone here ever met them & have any tips?

                    Thanks

                    Tim
                    Tim,

                    the "air cylinder spring" will probably be a cylinder with pressurised air on one side of a/the diaphram and oil on the other - an "accumulator".

                    If the diaphram is not perished or holed and if the shraeder vavle is OK and if the hydraulics are OK, why not use a petrol-driven compressor to re-charge the accumulator and see how it goes.

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                    • #11
                      Originally posted by oldtiffie View Post
                      Tim,

                      the "air cylinder spring" will probably be a cylinder with pressurised air on one side of a/the diaphram and oil on the other - an "accumulator".

                      If the diaphram is not perished or holed and if the shraeder vavle is OK and if the hydraulics are OK, why not use a petrol-driven compressor to re-charge the accumulator and see how it goes.
                      Tiff

                      My original post refers to the motor not functioning, not a lack of pressure.

                      The system works at up of 2000 psi,I'd be surprised if a Schrader valve would cope with that. The Berger type has a Nitrogen-filled gas spring, but they work at over 4000 psi. I don't know what the accumulator consists of in this case, it is substantially bigger than the Berger type but superficially similar external construction.

                      I spent some time playing with it this afternoon, my conclusion was that the motor assembly needs to be stripped & checked but that will have to wait for another day. It's GM's own product, unfortunately the engine manual goes into a lot of detail on overhauling the electric starter motors but no reference to the hydraulic type.

                      Tim

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                      • #12
                        Mr Fluffy: We have drag bikes that start by one inch, 12 volt impacts. This might be what you need. This impact provides the torque needed to remove 2400/24 ? tires off trucks, Wayne.

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                        • #13
                          Originally posted by wtrueman View Post
                          Mr Fluffy: We have drag bikes that start by one inch, 12 volt impacts. This might be what you need. This impact provides the torque needed to remove 2400/24 ? tires off trucks, Wayne.
                          I can't say I've ever seen a 12 volt 1 inch drive impact for removing truck wheels, not saying they don't exist, just all of the ones I've seen were 1 inch air operated.
                          I wouldn't think you'd want an impact trying to turn the engine over. Would it not just hammer rather than turn?
                          Have you got a link to that? You've piqued my curiosity.

                          As far as drag bike starters goes all I've ever seen were the 12 or 24 volt cart mounted or hand held units with spine drives or 3/4" sq. drives and overrunning clutches. These usually connect directly to the engine's crank.

                          Like this 12 volt one:

                          Home, down in the valley behind the Red Angus
                          Bad Decisions Make Good Stories​

                          Location: British Columbia

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                          • #14
                            Well, I eventually got to sorting this job.

                            It turned out that there were two issues. The unit had not been run for four years, sitting on the dockside (salty atmosphere).
                            The starter is a pre-engaged device, with the same nose as the electric version. The pinion slides on splines on the main shaft, and is pulled into engagement with the ring gear by a lever which also operates the hydraulic control valve. The pinion was seized (rusted) onto the splines, so as well as not being able to engage it prevented the hydraulic motor from receiving any power.
                            The whole thing was duly stripped, cleaned, greased, reassembled.
                            Then came the next issue - pumping by hand, the accumulator went very quickly up to max pressure (3000 psi). The accumulator is a cylinder with Nitrogen at one end, and oil at the other, with a free piston between the two. It didn't take long to establish that there was no gas in the cylinder, in fact the charging valve was damaged.
                            Luckily it had a Schrader part number still visible, and I was able to find one, NOS, on US ebay.




                            Then I needed a way to couple a gas supply to this valve, luckily the adapter turns out to be one which is commonly used for charging struts on light aircraft. As private flying is a much bigger thing in the US than here, the simplest way to get one was by mail order from across the pond.
                            When these parts arrived, I had to make up some kit for charging the accumulator to 1250 psi from a Nitrogen cylinder:-



                            The regulator isn't in use as such, it's just a convenient way to connect the high-pressure control valve to the cylinder and provide a contents gauge.

                            That job done - there was just enough gas in the smallest size of cylinder to charge it - two of us spent a happy couple of hours pumping up the accumulator by hand - takes maybe 20 minutes and is hard going by the end - and discharging it again through the starter in a matter of moments. We charged it fully at least four times, probably five, the hand pump is set up so that it's a sideways movement across the body, my arms and shoulders will be sore in the morning. Eventually it fired up, and ran smoothly, after which I restarted it several times which it did really easily on only a fraction of a charge from the accumulator.

                            Edit - machining content - I had to make that gauge tee myself because I couldn't readily find anything ready-made to do the job and withstand the pressure. It's 1/4" NPT inlet and for the gauge, and 1/8" NPT out. I just went for major overkill on size to be sure it's adequate. The proportions are greater than those of the control valve, which is marked as suitable for 4000 psi.

                            Tim
                            Last edited by Timleech; 11-23-2012, 02:53 PM.

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                            • #15
                              Some guys get all the cool jobs, well done.
                              mark costello-Low speed steel

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