# electric over hydraulic



## ropensaddle (Mar 30, 2007)

I have a one ton dump with an electric over hydraulic pump that started leaking. It leaks bad my question is could the power steering pump be plumbed to operate the cylinder? It is a single acting cylinder with vent, thought of plumbing a valve to power up off steering pump. Don't know how to get it down with no return line some kind of bypass? Also will the pump pressure operatethe cylinder? Was not impressed with electric when was working had loads that needed help to dump! I staked up four foot sides for chips but when loaded pump struggled and stalled a few times !!!1


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## Husky137 (Mar 30, 2007)

I don't know anything about plumbing into your power steering but your problem with dumping has to do with the pump and not the electric motor. I have a six ton hoist on my one ton truck that is electric over hydraulic. It has never balked at anything I've dumped. You need a stronger hydraulic pump.


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## ropensaddle (Mar 30, 2007)

Thanks, before someone got the wrong idea was going to be
a separate steering pump! I sometimes forget people do not read minds lol.


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## Husky137 (Mar 30, 2007)

Just make sure your dump body and other hoist hardware is strong enough to handle the load, if you go with stronger pump.


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## ShoerFast (Mar 30, 2007)

P S Pumps are rotary-vain type pumps, and not a lot of pressure, but a good volume, Electric ~ Hyd pumps, are usually garroter style, higher pressure. 

Just about every time, fixing what worked, will work the best!


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## ASEMASTER (Mar 31, 2007)

*ps. pump*

power steering pumps generate 1700 psi .


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## infomet (Mar 31, 2007)

This sounds fishy to me! What do you mean by "single acting with vent"?
If it's a hydraulic cylinder, you have to have a return line. Otherwise, fluid would be lost immediately! Are you sure you don't have an air cylinder?

These people sell kits to tap into the vehicle steering system. http://www.winchesplus.com/winchmenu.html

There's no reason to have a separate pump, as long as the engine can run while dumping. They will also likely know the spec's of your truck pump.

If you can find the spec's on the electric unit, you can design the new one accordingly. Obviously you have to have enough fluid stored to fill the cylinder, which you can calculate using the measured diameter and length.

You can incorporate an accumulator to get more flow and raise the dump more quickly. An accumulator is a bladder tank pressurized by the pump and kept ready for use. They may be a little dangerous for use under a truck. All the dumps I've used (very few) have had PTO driven pumps.

Of course the whole trouble may be caused by the original unit being worn out!


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## sawyerDave (Apr 4, 2007)

*Hydraulic pump*

Infomet might be a little confused here. You can rig up a single acting cylinder, and you can use a power steering pump to power it. A single acting cylinder has one hose plumbed from the valve to the cylinder. The other hose connection is fitted with a vent. The valve you use will have 3 ports. 1 from pump output, 1 to cylinder, and 1 to return on pump/reservoir. I personally haven't tried this for a dump application, but I have picked up many a snow plow with this set up. A good source of hyd parts is Surpluscenter.com :blob4:  :blob4: :fart:


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## infomet (Apr 5, 2007)

Yep, I was off the track!
I never thought of leaving one side open to the air.
There won't be any oil on the rod side, as long as the rings hold.
I'd love to find a table giving the pressure ratings and flow rate vs RPM for common power steering pumps. Hey, if one had a good source (friendly junkyard) one could use more than one pump to get more flow.


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## sawyerDave (Apr 5, 2007)

*Hydraulic info*

Infomet: A good source for this type of info is the surpluscenter.com catalog. Whenever I come across a hydraulic pump at an auction cheap, I buy it, then look it up in the catalog to see if I can ID the pump make. Sometimes you get lucky and can find the numbers, and figure out displacement, pressure etc. I don't use too many auto type pumps, because the pressures just aren't high enough for the applications that I work with.


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## CylinderService (Apr 6, 2007)

Most power steering pumps don't have enough flow and/or pressure to run things like small dump bodies or logsplitters , otherwise everyone would be using them and the junkyards would be bare! 
The force on a cylinder is the result of pressure of the pump applied to the cylinder's piston. PSI from the pump x piston area = force. If the truck won't dump a heavy load, you need either more pressure from the pump, or a larger cylinder. You might be able to increase pump pressure by setting the relief valve higher, but use a gauge in the line so you don't set it too high.
Don't get confused though, usually a "bigger" pump puts out more Flow (GPM), not more Pressure (PSI). That will move the cylinder faster, but won't help with force.

Don the Hydraulics Guy


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## ropensaddle (Apr 8, 2007)

Bought a electric over today sales man told me my pump was problem!
Not; the new pump stalls as well, dump bed is 9 foot on a one ton and sides staked up four feet with ply wood and channel for support it does ok if its just chips but wood stalls. I guess it,s cylinder? It was one of those dump scissor kits I think I,m not impressed and am thinking of using my other one ton 78 f 350 granny with pto so can have more options and building dump bed that really dumps, this getting frustrating and costly for a chip truck that I only use when can,t get grapple to brush or when not enough to warrant use of grapple! The 78 is bad boy has in out winch, and set up for gin poles and was going to keep it for that. The granny four is tough and the pto winch will pull anything hate to change but need a good one ton dump that doesn't stall


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## CylinderService (Apr 9, 2007)

*Dump truck won't dump*

Not to put too sharp a point on it, but I think a gauge would have been cheaper than a pump.
If it won't lift with 2500 PSI on it, then you need a larger bore cylinder, or maybe 2 cylinders instead of one. If you're not getting 2500 PSI, try increasing the relief setting. If it won't go that high, the pump may be worn out. That isn't the only possibility though. 
But of course, no matter what you do, the structure must be strong enough to handle the additional load, so the cylinder doesn't just drive its way through the bottom of the box. 

Don


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## infomet (Apr 9, 2007)

Yea, if a new pump is stalling, there can't be much wrong.
Cylinder seems to be in the business, but increasing the relief setting won't help a stalled pump, if stalled means stopped and not running.
Do you really mean stalled out, or do you mean the pump is running and nothing is moving? That would be running on the relief valve.
I got some wood from a yard man a few days ago. He hauled it in an F250 or 350 dually diesel with a four foot high dump bed. The bed was heavy built and EASILY dumped the full load of green white oak...a cord or a little more.
She was stacked full at the front but not quite full at the back. I forgot about this post and didn't look at the machinery, but I'll bet it was a PTO rig because I don't remember the pump whining. Worked beautifully.
Now I have some hours of splitting to do. I was sorry I didn't catch them until the big oak was bucked up. It had about 30 feet of straight, clear trunk, a crime to burn up!

Can you return the new pump?
I'll bet a bigger cylinder is $500 or more, unless you can find a used one.


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