The machine worked ok and then parked for 4 months and now when started the hydraulics are NOT working, suspect pilot act needs bleeding. However as the operator interlock micro switch wiring is suspect I fed 24vdc directly from batteries to pilot solenoid valve and it "clicks when power applied" so sounds like its working ok but still no Hydraulics, does anyone have a schematic for the pilot hydraulics or can anyone indicate where to bleed the pilot cct. I believe the PH hydraulics run at 700psi what fittings do I need for the pressure test points ? any help would be appreciated greatly
Hi Helipilot Kobelco typically used inverted BSP fittings and bspp threaded ports, 1/4 and 3/8 for a lot of the pilot system. you should have a 1/4" bspp plug coming off the pilot pump pressure fitting for a connection of a test point and for bleeding. Best regards
Thanks Kobe, can you indicate where to check the pressure, I have attached ac couple of photos the first is the pilot pump and I think the pressure regulator for the pilot CCT where should I connect the gauge ? and what pressure should I expect ? The second picture is the pilot interlock solenoid, as you can see Ive fed this directly from the battery to eliminate the interlock wiring/switch, where can I connect the gauge to see if its working ? Thanks again for your response Regards Helipilot
Is that the UK’s version of UL underground burial house wire? Why the Orange and Blue colors? Is this the same machine with the chewed up final?
I have attached and labeled your pic of the location for testing the pilot pump pressure test point plug. These threads should be 1/4 or 3/8 bspp from memory. I will need too double check the location for the pilot lockout solenoid as the one in the pic you have sent doesn't look familiar to me and it is not in the location that I remember them to be. That being said, I'm less familiar with the -4 models as that was not a model found in my area of the globe. I'm familiar with mark 3 and 5 models and the -3 is somewhat identical to your model. I will come back to you on this. The pilot pressure spec is 700 psi max @2400 engine rpm. The pilot pressure adjustment should be on the block you see in the pic on the right side of the pump mounted on the sidewall. There may also be a small screen filter in there as well. Best regards
Please see attachment below regarding your query on the lever lock solenoid. In the attachment you will see that the manifold for the lever lock solenoid is different to the one in your pic and is located under or behind the cab area. You may need to verify if your system has been modified and that you are checking the correct solenoid. If you need to test the lever lock hydraulically then you can place a test point in line with its pressure output port or place the test point directly into the solenoids output port, then operate the lever lock and verify the pilot pressure on the gauge. The solenoid manifolds ports are usually labeled P, T , A1, A2, A3 etc. Hope this helps Best regards
Kobe Thanks for the response, I will check the pilot pressure at the pump and work along from there. Harleyhappy, you are correct, that is the machine that "chewed the Hydash drive" its my son-in-laws machine and whilst he's a brilliant joiner/builder he's not a mechanic and we need to get the machine working so we can sort out the Hydash drive. Im an ex underground sparky and its not my finest work but the domestic cable on the solenoid was all we had to hand when I was there and is only a temp install to eliminate the interlock micro and wiring. I will get the pressure washer to it this weekend and see if the ports are labeled and start testing the pilot hydraulics as advised. We've had this machine for private use over ten years and been a very reliable machine helping build both my son-in-laws house and mine and as we have not been able to get any professional local help all advice is very much appreciated. Helipilot
Kobe Steel I assume the pilot hyd. pressure is held at 700psi by the pressure regulator just prior to the Tank return line ? if so is it possible to bleed the pilot hydraulics by simply loosing the "P" line on the regulator or is my toooo basic ? any chance that have a circuit diagram so I can try and figure it out ? Thanks Helipilot
Hi Helipilot Yes the pilot pressure is maintained by the pilot relief valve setting, see document attached for this adjustment. For any pilot lines that you may need to bleed air from can be loosened and bleed from its fitting but I would recommend bleeding by keeping the emergency stop cable out and only jogging the engine over and not starting as its gets very messy and even low pressure pilot oil can still cause serious injury if it hits you. It takes around 100 psi of oil pressure to pierce the human body and the pilot system operates at 7 times that. The only schematic I have is from the 120 mark 3 version but this should be very similar to the system you have. Sorry but the quality is not the best, see attached Best regards
Kobe Steel Brilliant, thanks for the info and safety advice. Ill let you know how we get on when I get over to the machine next week. Regards Helipilot
Kobe. Steel thanks again for the info/support/advice, So this morning I went over to the machine and started pressure testing along the pilot Hyd line and at the pump the pressure was as shown in picture *1, 450-500psi (High RPM's) !!! next line checked was the solenoid valve (picture *2) , its this valve that I thought was the pilot safety isolation valve powered from the micro switch on the interlock lever on the operators seat. However after chasing g the hyd lines it transpires that this solenoid valve is for the Quick hitch bucket ram DOH!! and so obviously not the safety interlock valve we are looking for. I removed the cover plate from under the machine cab area and found this Picture *3 and its clear that this is the safety interlock solenoid as it had Pilot hyd lines to it and following the wiring all the way back to the microswitch. I assume in its unpowered state the P port is open to the T port and therefore pilot hyd pressure is "dumped" back to the tank, and when powered (interlock lever lowered and micro switch made) the solenoid is energised and pilot hyd pressure is ported to the controls and actuators are supplied, if so is this the reason why the pilot hyd pressure is low ? and when powered up will the pressure reading at the pump increase due to the restricted flow ? . I removed the 24v coil from the solenoid and when tested found it open circuit !!!. Im now searching for a replacement coil (Picture 4) if anyone knows where to get one please advise asap. the name/part number on the solenoid is Uchida Rexroth 4WE6D-60M0/AG24NFAD Best regards Helipilot
The pilot lever lock and 2 speed spool configurations I have seen in the past look different to the coil and spool assembly in your pic #3. see below parts diagram for lever lock and 2 speed block and coil set up I'm referring to. This is usually also found under the cab. Typically the pilot pressure line is normally closed at the p port of the lever lock and travel 2 speed spools when the coils are not energized. Pilot circuit pressure must remain at all times at the pilot pump when the engine is running and be relieved to tank via the pilot pressure relief valve only. Best regards