Need help with hydraulic problem

   / Need help with hydraulic problem #1  

Anonymous Poster

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I'm hoping someone can help me diagnose a hydraulic problem. I just got a postdriver that I want to run on my B2710, and I'm completely ignorant about hydraulics.

The postdriver has a single control lever with three positions -- up, neutral, and down. Neutral is the position it stays in if untouched. Because of it's special use, the postdriver has a large diameter return tube that goes directly into the hyrdrauilic reservoir, rather than using a return line with a quck coupler.

Also my tractor is fitted with an extra hydraulic circuit, which was intended to be used for a hydraulic toplink and a cement mixer. It originates at the box at the base of the FEL controller lever. I returned the cement mixer and never got the hydraulic toplink, so I normally keep the two tubes that comprise this circuit connected together with their quick couplers. If the tubes are disconnected, the tractor bogs down.

If I separate the two tubes that comprise the extra circuit, and attach the input line to the postdriver, the tractor does not bog down, so I belive that hydaulic oil is flowing normally. If I push the postdiriver controller lever down -- meaning drop the driver --- the tractor bogs down, but the postdriver doesn't even wiggle. There is room for the postdriver to slide down a little on its tracks. Thereis a safety pin, but I removed it. If I push the lever up, nothing happens at all. In addition, when the postdriver is hooked up, moving the three-point lever has no effect at all. This in of itself witl be a problem if I can't fix it.

Finally, the person who installed the cement mixer told me to use the male end of the extra hydraulic circuit as the input to the postdriver. I believe he was mistaken, as the tractor bogs down in this configuration, regardless of the position of the lever.

Thanks in advance!
 
   / Need help with hydraulic problem #2  
Hi ya
i can't pic how this has been done so i may need some more info
have ya got fatory remotes??if so plug post driver in to one of them making sure ya have the leaver (on tractor !!)in working position so ya use the post drivers hyro bank to do the work..when ya say ya have this extra port connected ya mean in a loop one pluged in to the other?? ..it sounds to me as if it's pumping all the time
ok now post driver is fully lifted?? take ya hoses out of the tractor (warning !!!!!!!!!!!!!!!!! keep people away and watch ya self for what i'm telling ya is not the done thing but will show something)now make both ends open ie take the ends off and SLOWY (READ AS VERY SLOWY!!!)move the lever to lower the ram/hammer/driver oil will come out of one hose that is ya return hose ...i'm thinking it may be plumbed wrong..ok now we have a inlet and return port worked out if hoses wrong swap hoses so big hose is ya dump hose ...i just have a bad feeling that who ever put the extra bank in did not do it right i think it sounds like it's is running all the time where it should be on demand ,i'll think more on this and let ya know ...
catch ya
JD Kid
 
   / Need help with hydraulic problem #3  
Don
How many hoses does your post-driver have? I'm going to assume you only have 2. If that is true, one line that you normally keep connected with hose is pressure. Other line should be connected to return line on your post-driver. By hooking up return line to your return on transmission there is no oil to 3 PH. Hope this helps.


18-30594-ronssig2.gif
 
   / Need help with hydraulic problem #4  
Don,
First what type of post driver do you have? Next you might be trying to run an open system on a closed system in the hydraulic box on the post driver. Your post driver will either come with an open or a closed system from the factory. You have to hook up your hydraulics based on this. Also make sure you have your driver connections right from the driver itself to the driver hydraulic box.

18-35034-TRACTO~1.GIF
 
   / Need help with hydraulic problem
  • Thread Starter
#5  
Hi jdkid,

No factory remotes I'm afraid. I think I'm using the right end of the hose -- I lifted the return line out of the reservoir and I saw a good flow of oil coming out. I guess that means yes, it is pumping all the time.

Come to think of it, when I returned the cement mixer I returned the valve that was supposed to drive it. It had four hoses connected to it. I'm guessing now that if I install one of these valves again I'll be able to use my 3PH again. This hydraulic stuff is starting to come a little clearer now.

Still doesn't explain why the hydraulic flow backs up when I push the postdriver lever down (I can see the hose jerk and the tractor bogs down), but does nothing at all when I push the lever up or leave it in neutral.
 
   / Need help with hydraulic problem
  • Thread Starter
#6  
It has three hoses, all connected to the postdriver valve. One goes to the hydraulic cylinder which lifts the ram; one goes to the oil reservoir; the third connects to the hydraulic input line.

As I mentioned to jdkid, I'm thinking now that I need to get an extra valve with a diverter so that I can use either the 3PH or the postdriver at any one time. Does this sound right?

Thanks.
 
   / Need help with hydraulic problem
  • Thread Starter
#7  
The postdriver is a Worksaver HPD16. It ships to run on an open hydraulic system, as is my tractor (it's convertible however).

The connection between the hydraulic box and the driver seems okay. There is oil flowing through into the reservoir.

Thanks
Don
 
   / Need help with hydraulic problem
  • Thread Starter
#8  
The hoses are hooked up improperly at the valve. The pressure line from your pump needs to go to the port that will deliver flo from the pump to fill the cylinder when you put the handle in lift position. The hose to the reservoir should dump oil from the cylinder when you move the handle to the drop position.
The 3 point ain't working cause your post driver is connected to the hydraulic pressure line and id dumping all oil back to the reservoir.
This diagnosis is based on your description of a single acting cylinder on the post driver.
A diverter valve might solve the problem but shouldn't be necessary. You should be able to use the 3 point by holding the driver valve in the up position with the hammer fully up.
 
   / Need help with hydraulic problem #9  
Don
Attached is an illustration of Hydraulic circuit from the 27-2910 <font color=orange>Kubota</font color=orange> Work Shop Manual. The return line of Post-Driver needs to be hooked up to the second line where FEL valve is hooked to side of tractor. Hope this helps you figure out how to hook up lines.


18-30594-ronssig2.gif
 
   / Need help with hydraulic problem
  • Thread Starter
#10  
Hi Ron,

Try scanning @ 400 dpi (or up to 600 dpi and scale the size down) in B/W mode and maybe adjusting the contrast to avoid picking up "page bleed through" {seeing the text on the reverse side}...

This produces a much cleaner and sharper B/W text than using grayscale mode... {then you can only edit in b/w mode not color} /w3tcompact/icons/wink.gif

18-35196-JDMFWDSigJFM.JPG
 
 
 
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