Pronovost trailer hydraulic question

[sailnseagulls]

Ron,
Yes, that's exactly what my remotes are. One of the spools also has a float position. I was thinking that if I connected to one of its' ports, that I could use the float position to lower the dump.
I saw that the trailers that did not come with the optional manual pump had two hoses on the cylinders to connect to the tractor. Am I right in guessing that the advantage to this is that you then would not depend on gravity to lower and would not be using the tractor fluid to raise as it is sort of a closed system ?

 

[sailnseagulls]

Hi Al,
My trailer is the P-503 model but works exactly the same way.
I'd like to see a pic of the valve your dealer put in the line. My understanding is that you then just turn it depending on whether you want to use the pump or tractor to raise.
Do you think I could avoid this by putting a QC on the manual pump with a male end QC on the hose ? Then simply connect the hose to the tractor or to the pump as needed?
I see what you mean about using the shut off on the pump itself and not needing a valve but rather just a "T" in the hose.
I was just thinking that I couldn't screw up if I didn't have both tractor and manual pump connected at the same time.
Thanks for your thoughts.

 

[sailnseagulls]

Mad,
Thanks for your help. I have read most of your posts and have gained a lot of knowledge from you.
I'm thinking that I would be pretty safe in using the dump with the one line connected to the valve. Seems that if I replace the manual pump fluid with the same as in the tractor, fill the hose, then top off the tractor I should be ok.
Does using the float position of the valve to dump sound right to you? And, am I right that there is no way to use two hoses (double acting cylinder) and still be able to connect to the manual pump when I want to?
Larry

 

[MadReferee]

Only one position of the control spool will have float so you have to figure out which of the remote ports will have pressure when that position is activated and use it for the cylinder. Float works by essentially directing both of the spool work ports to tank, thus relieving pressure from both sides of the cylinder. I don't see why this wouldn't work for what you want to do.

 

[VT_Kioti]

Hi Larry
I hit the wrong key...mine is a P-503 also. Here is a picture of the valve as the dealer mounted it. However, I have always wondered if the shut off on the pump would do the job itself since it is strong enough to prevent flow back into the pump when the body is being pumped up fully loaded.

 

[RonMar]

Larry
I don't think you need to use float. As Madreferee said, float just connects both sides of the cylinder to each other and to the resovoir to allow an impliment to float over the terrain under it's own weight. Since you are only using one port, when the lever is placed in a position to lower this trailer, you are connecting the port to the resovoir, Same end result. By using the regular control lever, you will also be able to control the lowering speed. Full down might be too fast and would require that you put a restrictor in the line to slow the lowering speed when using float. Since it is a single line, this would also restrict the lifting speed. By the pics that VT Kioti posted, the valve on the manual pump is a screw type which will give fine control of the lowering speed, much like that found on a hydraulic floor jack or engine hoist.

VT Kioti, At first look, I would say that the valve the dealer installed was probably not needed. As you stated, the installed valve is capable of holding the hydraulic load of lifting a fully loaded trailer. I guess it would be good to have if you were trying to dump more weight than the hydraulics were rated for.

VT Kioti, What happens if you try and pump the manual pump with that extra valve closed?

If you can still pump, I would say that there is an internal safety on that manual pump that bypasses back to the resovoir if you try and dump too much of a load in the trailer.

If you tried to dump too much weight using the tractor hydraulics without that valve installed, it is possible that the safety on that manual pump could dump(if set lower than the safety on the tractor) to the manual resovoir and overflow it. That ball valve also has the advantage of being able to be clearly seen in the open or closed position from a distance.

 

[VT_Kioti]

Ron
</font><font color="blue" class="small">( <font color="blue"> By the pics that VT Kioti posted, the valve on the manual pump is a screw type which will give fine control of the lowering speed, much like that found on a hydraulic floor jack or engine hoist. </font> )</font>

The valve on the manual Pump does just that. You can slow the body down very slow with it.

</font><font color="blue" class="small">( <font color="blue"> VT Kioti, What happens if you try and pump the manual pump with that extra valve closed? </font> )</font>

Have not tried that. A very good question. The only problem I can see is as you stated..If the valve on the manual pump is not rated for 2500psi or more it may just blow the valve when tractor pressure is applied.

Thanks for the suggestions. i guess it is safer with the dealer installed valve. With it, the manual pump Valve is protected.

 

[sailnseagulls]

Al,
Thank you for taking the time to take the pic. It is exactly the set up I have. I see your point and I think you are right that the shut off valve probably is not needed but would work as a another safety measure from the pressure of the tractor hydraulics. Again, I was thinking along the lines of just replacing the original hose with a longer one and then putting a QC on the pump. It would then bypass the hand pump all together when hooked up to the tractor and simply hook to the hand pump when pulled by the truck. Thanks again for all your time.
Larrry

 

[sailnseagulls]

Ron,
I hadn't thought of that when thinking I should use float to return the dumped trailer. Your answer makes much more sense as I could regulate the speed it closes with the valve.
I just went out and used the hand pump on the trailer. I can tell you that when fully extended, you can't move the handle anymore which tends to make me think there is no internal safety on the pump. When you relieve the pressure with the knob, you can move the handle again.
Larry