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Hydraulic pump?????


Bunky

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I would say whatever you can find that's cheap. The one I have on my 9020 loader/b.hoe was salvaged from a PTO rotary air compressor. I wasn't even sure it would do the job but it works good. I think a look at surplus center website would turn up a good bargain. I always thought about using a two stage pump, but I probably would break something then. (3000 psi compared to 1500-2000). About 12 GPM would do the job. I made a quick attaching jackshaft/lovejoy assembly that mounts under the engine and drives from the front elec. clutch PTO. This way you can start the tractor without the hyd. oil dragging along. This makes a big difference when it's 10 deg. out.
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Hydrolic components have ratings set up to work with the load reqired of them ie, flow, presure, and hp input. Most pumps do not have a relief valve built into the pump. They rely on an external relief vavle usually built into the valve body that you control the flow with.As for two stag pumps, the second stage does not duble the presure, it cuts the load in half by switching the flow inside the pump so the same powerplant can produce the reqired presure. Let me see if I can say it simpler. By example lots of wood splitters have 8 HP engines with 2 stage pumps producing around 20 tons of force on the wedge. Now the working presure veries under wich part of the stroke needs the matching load. The force of presure comes from the diamiter of the cyl. Thats why the splitter cyl. are so big around. It takes a lot of FLOW to move that big cyl. so both stages of the pump act like piggyback pumps and pump ruffly twice what the same size single stage pump would. It also takes more power to pump that much oil, but remember you haven't built any real presure yet just moveing the cyl. before you hit the wood. As the wedge encouters the wood and the working presure increses and the flow reqirment decreases, the pump has a flow control valve that shfts and cuts off one section of the pump makeing it a single stage pump for building high presure. The reason for this is low presure flow doesn't reqire large HP, but large flow at high presure reqires great HP. Remember the relief valve is located in the control valve on most systems and is always set to designed specs. You never use the relief valve until high PRESURE is built up in the system. Both 1 and2 stage pumps are able to produce the same presure, but we would all be cold waiting for a single stage pump to move that big cyl. enough to get the wedge to the wood. The use of the 2 stage pump give you the most out of a smaller engine and still get propper presure. Most standard hyd. systems relief valves are set at 2000 to 2500 psi. Hydrosatic trans. circuts can go as high as 6000 psi but the componets in these systems are made for this presure. All reief valves are set with presure gauges in the system while under load. Under no circumstances should anyone change these settings without knowing what they are doing. A busted hose at any presure is a mess, one at 1000 psi or more is life threatning. I know this has been rather long winded but I tried to cover the prpper info so you could understand that your ? is not clearcut. For your answer a small single stage pump is probably what you need at about 10 Gallons per minute. Hope this helps, Dave.
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I am a real novice on this subject. No, I don't know anything at all about it LOL:(. I thought that the question posed was what pump? Where do you get them? Will a power steering pump work for some simple applications? All I would want to do is lift a snow blade or turn it from one side to the other. Once had an M Farmall that had an after market, home made system on it that used a 5 gallon oil reservoir. Would I need something like that? Lots of questions here:D Dan
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Well I just wanted to know what people where using on the there tractors for a pump if they have a loader or other hydraulic ran apperatus's.......... I'm looking into building me a loader or maybe a rear lift of some sort someday and wanted to know what I would need for a pump...
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I am planning to use a power steering pump from a Chevy. I have two in the garage. 1500psi bypass is internal and they pump about 2 gallons per minute. May be a little slow, but I have lots of time. A friend has two homemade tractors with hydraulics using power steering pumps. They power a forklift and two different dump trailers that he has made. He swears by them. If he needs more force, he modifys the bypass valve to raise the pressure.
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Dave Thanks for the easy to understand explination. Thats exactly why I am learning to love this sight. I learn something every visit. John
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Here's the specs for the L-12 loader: Pump capacity: 1-1/2 GPM @ 2000 RPM Relief valve setting: 1500 PSI Note that it does not have dual-action lift cylinders on the arms (gravity brings the bucket down), and only one dual-action cylinder to dump the bucket. http://www.simpletractors.com/attachments/l-12_specs.htm
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