Snowplow hydraulics

   / Snowplow hydraulics
  • Thread Starter
#11  
Hoses and fittings are all 1/4". Hi and lo pressure hoses are 20" long, hose to cylinder is about 4 ft. When used on the old Ferguson tractor, the cylinder hose was about 6 ft, but still only 1/4". Small hoses, but pump is only 5 gpm. One more thought--oil at time of test was cold. FWIW supply lines for FEL are 3/8"
 
   / Snowplow hydraulics #12  
In order for a single acting cylinder to collapse, the oil must return to the tank. The speed of that is dependent upon the amount of fluid that can pass through the smallest opening and the force applied to collapse the ram. Cam
 
   / Snowplow hydraulics
  • Thread Starter
#13  
In order for a single acting cylinder to collapse, the oil must return to the tank. The speed of that is dependent upon the amount of fluid that can pass through the smallest opening and the force applied to collapse the ram. Cam
I'll see how things work after a real-life plowing exercise. We had a few inches of heavy wet snow in December--before I got the plow, but it has all melted, and there is none in the forecast. I may need to upgrade the return line to 3/8"
 
   / Snowplow hydraulics
  • Thread Starter
#14  
Update--We have had two storms which required plowing. The hydraulics worked OK, but slow enough to indicate something just isn't right. Unrelated to this issue I plumbed a coupler into the work hose so I could completely separate the valve from the plow. Now there is pressure to the work port in both handle positions, and the cylinder will not collapse----however, if I shut off the engine and push the handle forward, the cylinder collapses just as I would expect. In reviewing the valve instructions, they said there is a plug in the outlet which must be removed if it is to act as an open spool. I removed the fitting in the outlet and could see there is no plug and the operating spool is clearly visible. I have reviewed the tractor manual re: hydraulic manifold and know the valve is plumbed correctly---tractor out to valve in, valve out to tractor in. I know I could remove the newly-installed coupler and return to original configuration, but I don't see how my problems are related to that. All I can think of is that there is some manufacturing defect or internal adjustment needed. Thoughts and recommendations requested.
 
   / Snowplow hydraulics #15  
Update--We have had two storms which required plowing. The hydraulics worked OK, but slow enough to indicate something just isn't right. Unrelated to this issue I plumbed a coupler into the work hose so I could completely separate the valve from the plow. Now there is pressure to the work port in both handle positions, and the cylinder will not collapse----however, if I shut off the engine and push the handle forward, the cylinder collapses just as I would expect. In reviewing the valve instructions, they said there is a plug in the outlet which must be removed if it is to act as an open spool. I removed the fitting in the outlet and could see there is no plug and the operating spool is clearly visible. I have reviewed the tractor manual re: hydraulic manifold and know the valve is plumbed correctly---tractor out to valve in, valve out to tractor in. I know I could remove the newly-installed coupler and return to original configuration, but I don't see how my problems are related to that. All I can think of is that there is some manufacturing defect or internal adjustment needed. Thoughts and recommendations requested.
No idea how you plumbed it or what is going on based off your description
Pictures showing what is plumbed and where would be a big first start
 
   / Snowplow hydraulics
  • Thread Starter
#16  
Would love to send pics, but my computer died and I don't know how to download shots from my ipad to my wife's laptop. Fortunately, there is no snow in the forecast, so will have to wait til computer is repaired to continue this discussion.
 
   / Snowplow hydraulics
  • Thread Starter
#17  
Update.2 Here are pics of valve and plumbing. The connector shown in #2 was previously a quick coupler, but it wasn't defective. As shown everything works, but cylinder still collapses slower than it should. Shut off engine, and it collapses quickly.
 

Attachments

  • IMG_1630.JPG
    IMG_1630.JPG
    2.7 MB · Views: 53
  • IMG_1631.JPG
    IMG_1631.JPG
    2.7 MB · Views: 53
  • IMG_1632.JPG
    IMG_1632.JPG
    2.3 MB · Views: 57
  • IMG_1633.JPG
    IMG_1633.JPG
    2.4 MB · Views: 56
  • IMG_1634.JPG
    IMG_1634.JPG
    2.2 MB · Views: 65
   / Snowplow hydraulics #19  
Thoughts and recommendations requested.
You've made this far more complicated than it needs to be. Get rid of the new valve. Simply swap the single acting cylinder for a double acting one.
 
   / Snowplow hydraulics #20  
I'm not sure how you have plumbed your valve, but I suspect that you have plumbed it as a power beyond.
This valve does not have that capability.

"Brand new PRINCE. RD2500 series. Hydraulic control valve for operating single acting cylinders. Monoblock high tensile strength gray cast iron body. Hard chrome plated spools. Open center with conversion plug for closed center applications. Load checks."

This valve can be used in an open center system, or a conversion plug added for a closed center system.
On your system which is open center the pressure feed needs to enter the valve at the Pressure port, then the return or T port must have unrestricted flow back to the tractors tank or reservoir the work port will go to your cylinder.
In normal operation all hydraulic flow will just pass through the valve from the pump to the tank with no restriction.
When the handle is operated to work the cylinder the valve piston is closing the flow through the valve and redirecting it to your cylinder.
When the handle is returned to neutral the flow is again directed to the tank and the fluid is locked to the cylinder. When the handle is operated to allow the cylinder to retract that flow is added to the flow that is passing through the valve from your pump.

The reason it will drop faster when the engine off is that you have no flow from the pump going through that small return line.

A double acting cylinder is not needed and will not work with that valve.
 
 
Top