Lars L Posted February 10, 2010 Share Posted February 10, 2010 In an attempt to get a little more speed out of my 9000 lbs MileMarker I opened up the orifice of the pump by 1 mm. The pump is used only for the winch and is a Saginaw "canned ham" pump out of some US pickup truck. Now, when revving the engine, the winch drum is moving without me touching the controls. Is this what would be expected if the flow is greater than the valve block, sitting on the winch motor, can handle? So when the flow increases over a certain level, it doesn't have anywhere else to go than into the winch motor? Quote Link to comment Share on other sites More sharing options...
BogMonster Posted February 11, 2010 Share Posted February 11, 2010 I wouldn't have thought so, off should be off Quote Link to comment Share on other sites More sharing options...
Lars L Posted February 11, 2010 Author Share Posted February 11, 2010 Yep, it's somewhat strange... I also e-mailed MileMarker with the same question and the reply was that there might be some debris in the valve. Then I don't know if he meant the valve on the pump or on the winch... When testing yesterday, the winch worked exactly as before with the engine idling. Crisp response when pushing the buttons on the remote control. And I could clearly see that it spooled faster when I increased the engine revs a little. But when the revs got too high, the winch slowed down to less than normal. When revving the engine, the drum moves without my input and the direction of rotation seems to be random... I'll test more later today. Quote Link to comment Share on other sites More sharing options...
Milemarker Type S Posted February 11, 2010 Share Posted February 11, 2010 I would say that you may have a small amount of debris inside the solenoid valve (possibly from drilling out the hole)- this may stop the valve spool moving to the fully closed position- hence the winch rotating slowly as a small amount of flow is leaking accross the ports. The additional flow from the pump (even with it drilled out) is not going to be to much for the original valve to handle- without the flap disc the valve can quite happily flow up to a maximum of 27 l/min. The valve is very easy to strip and then give a good clean out- just make sure that it is all very very clean when reassembled. It is also possible that one or more of the o rings inside the valve is worn or damaged- all can be replaced easily when the valve is stripped. HTH Si Quote Link to comment Share on other sites More sharing options...
Lars L Posted February 11, 2010 Author Share Posted February 11, 2010 I have taken the winch off today, removed the valve block and blown the internals backwards with compressed air and with open valves. Tomorrow will start with disassembling of the solenoid valve. A good benefit of being selfemployed... The pump orifice was cleaned before it came back, but who knows... Anyway, the winch went backwards at higher engine revs, so it was not random. Increasing the revs when running the winch inwards made it suddenly go slower, possibly indicating that oil was pushed into the wrong port as well. And yes, it could easily be seen that it went faster than before, especially at a little higher revs than normal idle. Quote Link to comment Share on other sites More sharing options...
Lars L Posted February 15, 2010 Author Share Posted February 15, 2010 By now I have taken the valve block and valve apart, rinsed it, blown it dry and carefully checked for any kind of debris. So now it's as clean as it can be. And it's still going backwards at higher engine revs... I have done what can be done and it's still not working properly. Next thing might be to put in a manual valve that directs the fluid back to the pump instead of taking the route via the winch valve and just switch it over when it's time to use the winch. I can easily see that drilling out the pump made a difference regarding speed and I don't want to loose that. Quote Link to comment Share on other sites More sharing options...
Milemarker Type S Posted February 15, 2010 Share Posted February 15, 2010 Did you check/ change the o ring seals inside the valve?- If not then that would be my next move. As I said before the flow though the valve, as long as it does not exceed the maximum flowrate, should not cause fluid to be leaking across to the winch ports as is clearly happening. I take it the winch works in both directions when you want it to? Quote Link to comment Share on other sites More sharing options...
Lars L Posted February 16, 2010 Author Share Posted February 16, 2010 Everything looked fine through the magnifying glass. The winch works exactly as it should at lower engine revs. Then I don't know about the flow rate of my pump. I drilled it up to get more speed, which I also got, and then these problems started. When looking at that spindly valve, I'm thinking that couldn't it be possible that being fed more flow than it can handle, actually could push the valve stem to one side just a wee bit and let a little oil pass... Manual valve for redirection when not in use or a magnetic clutch on the pump might be the solution. BTW, thanks for your inputs! Quote Link to comment Share on other sites More sharing options...
TD5 power Posted February 16, 2010 Share Posted February 16, 2010 hi what diameter hose are you using for the return side of the system as if this is too small it may allow pressure to back up causing strange valve problems. HTH matt Quote Link to comment Share on other sites More sharing options...
Lars L Posted February 16, 2010 Author Share Posted February 16, 2010 I'm using the one that was supplied with the winch. Originally intended to go between winch and steering box, but since this is a stand alone system, I used it for the return. The JIS couplings are the smallest size AFAIK, so the hose might be 1/4"? Maybe you have a point here... Noticed you are from Banbury. Been there... Quote Link to comment Share on other sites More sharing options...
Lars L Posted February 17, 2010 Author Share Posted February 17, 2010 And now - success! No drum moving without me wanting it to. I have installed a manual valve right after/before the pump between the pressure and return hoses. When this is open, the flow goes directly back to the pump without disturbing the valve block on the winch. Closing it will make the oil flow down to the winch and its valves as before. Now it's time to mate my hand throttle to the 200Tdi... Quote Link to comment Share on other sites More sharing options...
TD5 power Posted February 17, 2010 Share Posted February 17, 2010 hi although you found a solution, if the return is really 1/4" hose then that is way to small and will be holding the performance of the winch back. I would look at upping the pressure side to 3/8" and the return 1/2" you should be able to find a local ag engineer or hydraulics place to make the hoses up for you. Bit of a long trip all the way over hear from sweden Matt Quote Link to comment Share on other sites More sharing options...
Lars L Posted February 17, 2010 Author Share Posted February 17, 2010 Might be a future project, I'm fed up right now with dripping ATF oil. Quote Link to comment Share on other sites More sharing options...
calle-fas Posted February 18, 2010 Share Posted February 18, 2010 I would really recommend you to fix the return line. We used restraining valves to control the speed on a hydraulic powered sorting tool for an excavator. The problem was that both valves was two-way. We ended up blowing the motor when one of the valves was accidentally a little tighter than the other, this allowing more input than the retun could handle. Now we have a leak line (at least that's what it's called in Sweden ) in addition to the return line. We have also changed both the valves so that they only restrain pressure. Oh and by the way. Hydroscand will do just anything related to hydraulics. Dunlop Hiflex are good too. Quote Link to comment Share on other sites More sharing options...
Lars L Posted February 19, 2010 Author Share Posted February 19, 2010 My hydraulics business goes to Swedol - discount, you know. I don't really think that the size of the return line is the problem. The normal setup for this winch is pump - winch - steering box - back to pump. So with a standard setup, there is no option to use anything but a pressure hose. Anyway, my manual valve simply creates a bypass directly back to the pump, so there are no restrictions or one way valves in my system. Well, I'm not closing any doors, I will test a bigger diameter return hose later. Quote Link to comment Share on other sites More sharing options...
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