LW6 Bachoe problem

Forum Forums Tractor Implements LW6 Bachoe problem

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    • #30356
      streetrod
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        Hi , I has imported 2 LW6 units from China ,with hydraulic pump amounted on a pto gearbox , after assembly and filling them with grade 46 hydraulic fluid ,I install one on my tractor … nothing works , I have inverted the hoses on pump and miracle all the cylinders opérates as it should, but after one minute the pump shaft seal blows and a massive fluid leak under the pump gearbox , is somebody  can tell me what is wrong ? thanks  

      • #32756
        Bob Rooks
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          More than likely the relief valve is dirty and stuck so you dead-headed the pump. My guess is that you didn't flush the system first before you put it into service, so now that will have to be performed – after you clean out the reservoir and relief valve, and repair or replace the pump. Also be sure to have the correct relief valve setting when it's reassembled ~2,200 psig. Sorry.

          embarassed

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        • #32757
          streetrod
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            Hi ,

            Thanks you for fast reply ,I`m searching for a new pump and it seems most dealers are out of stock, I Think the problem occurs when I try to move the left big joystick , these backhoes are very cheap and bad welded , so there are the last…

          • #32760
            Bob Rooks
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              Check the nameplate on the pump, if it has a “CBN” number it is the same one used on the tractors, or at least it would be interchangeable. You need about 6-7 GPM and about 2,300 psi. You can also install a Prince PTO pump that slips over the splined shaft and runs in the 540 r/m range – no overdrive (“gearbox”) necessary (it's what I did).

              So, what happens when you move the left control? Are you moving it front to back or side to side?

               

              “…so there are the last…”

              What does that mean??

               

              Is this your first backhoe? Are you a certified five-position welder?

               

              Curious why you used AW46 hydraulic oil instead of AW32? Are you on the equator?

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            • #32761
              PrairieDog
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                Streetrod, let's go back to your original problem before you waste more money.

                First, you should not have interchanged the hoses.  As Bob Rooks said, the reason you had the first problem was probably due to dirt or some other problem in the relief valve.  It is possible to disassemble the inlet valving and inspect & clean, althugh you really do have to keep very close track of what goes where (take lots of photos).   And if you are removing any adjustment screw (like, one that adjusts the pressure setting) make sure you count the number of turns as you disassemble it and make sure you put it back in its original postion.

                When you interchanged the hoses, I believe you eliminated the relief valve from the circuit, thereby dead-heading the pump and causing the damage. 

                If you don't reconnect the pump in its proper (original) configuration you will just destroy another pump.

                Prairie Dog

              • #32786
                lenbo
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                  Streetrod

                  I have a like new (factory) pump that I took off my 354 for my LW-7. I replaced it with a Prince PTO pump. It was like night and day runing my BH with the Prince. If you are in a bind and can't get another pump. I'll give you my factory pump, just let me know and I'll ship it to you. My advise is to evently redo your hydraulic hoses from the reserviour tank to the pump & pump to the controls, and get a Prince pump.

                   

                  Len

                • #32798
                  streetrod
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                    Hi,

                    the reason why I have inverted the hoses is the 2 backhoes have the same problem and they are brand new… ,somebody told me maybe the hoses has been installed the wrong way because the gearbox turn in opposite direction??? these 2 backhoes are the first I have ordered from my supplier in China ,and I will not reorder any in the future due to this bad experience ,by now ,I have imported 15 Jinma tractors without any problems ,exept little oil leaks sometimes

                    I`m not a mechanic ,not more a hydraulic tech ,but usually i can solve lot of problems by myself ,but this time I admit its very expensive to try

                    I will buy a Prince pump as recommended and try to clean the relief valve ,and change oil for aw 32

                    also ,sorry for my bad english ,I`m a French canadian living in Quebec Canada

                    Thanks

                  • #32799
                    Bob Rooks
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                      The tractor engine is SAE standard left hand rotation (LHR). The upper tang drive PTO is straight through so therefore turns at engine speed and rotation, counter-clockwise, viewed as if you were standing at the rear facing forward. The CBN series hydraulic pumps are co-designed to attach to this PTO with four mounting bolts. In this configuration the pump suction will be on the left side regardless if the pump drive gear is on top or bottom, and will run at engine speed.

                      The lower splined PTO has two speeds, 540 and 720 or 1,000 r/m which changes the speed and rotation (clockwise) from that of the engine's through gear reduction. In order for the splined PTO to produce the rated speeds, the engine speed must be increased proportionately. The “gearbox” is actually an overdrive transmission which also changes (increases) the speed and direction (counter-clockwise) of rotation of the pump. This closely, if not exactly, resembles the original four bolt mounting scheme in performance – the advantage is that it slips on and off of the splined shaft.

                      The Prince pump is much more robust and simply slips on and off the splined PTO shaft without the need for a transmission. In my case the pump stays on the PTO shaft all the time (it's kinda heavy), I just uncouple the quick-connect fittings, and disengage the PTO.

                      cool

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