John Deere 5320 mid DSCV loader problem

[Kmicah40]

Hello everyone. I have an issue that I hope someone can help me with on my John Deere 5320. The DSCV (dual selective control valve) that my bucket loader operates from has quit working for the bucket in/out operation. I have switched the up and down hoses with the bucket in/out hoses and the bucket in/out will work and the up and down does not work. I pulled the spool that controls the in/out motion from the DSCV and did not see anything wrong there. The SCV is mid mounted. I was thinking the couplers might be the issue. What I did was break the couplers free and unscrewed them about 1/2 and activated the valve spool in and out. With the pressure I would think I would see some hydraulic fluid leaking around the threads, but I did not see any. The cable attached to the spool does work and moves the spool in and out as it should. It sure looks to me like the top half (up/down) has the hydraulic pressure when activating the spool in and out and lower half never sees pressure when moving the spool in/out. With how the system operates I do not see how that is possible since both are operated by same hydraulic lines. Hope someone has some help for me. Thanks
Larry

 

[jd110]

Remove plug #11 and check the poppet valve behind it. This is the load check valve. I ave found that a couple of these valves have gotten stuck in the bore. Be sure loader is on the ground before you remove the plug. The valve seems to tend to swell and get stuck. You can remover the valve and spring and then reinstall the threaded plug to test if it works then. Without the valve installed, loader will tend to leak down faster than normal most likely, but can be operated this way without a problem.

 

[Kmicah40]

Remove plug #11 and check the poppet valve behind it. This is the load check valve. I ave found that a couple of these valves have gotten stuck in the bore. Be sure loader is on the ground before you remove the plug. The valve seems to tend to swell and get stuck. You can remover the valve and spring and then reinstall the threaded plug to test if it works then. Without the valve installed, loader will tend to leak down faster than normal most likely, but can be operated this way without a problem.

Thanks jd110. I think that may have been my problem. I removed the plug and the small spring and found what looks like hard rubber or plastic. I was expecting to see a poppet that was smaller in diameter that would allow me to pry on it to get it free for removal. What I see is black plug that looks like it is snug fit to the bore. It is not metal and I could not get to move at all. So it must be stuck and wondering what method to use to get it free and removed. I was thinking of drilling and tapping a hole where the spring went in the poppet and use a screw to pull it out. You have any suggestions?
Thanks again for all your advice.
Larry

 

[jd110]

Although not the safest or cleanest method, I have started the tractor and operated the valve briefly to pressurize and blow out the poppet. If you try this, be sure to stand out of the way and make sure no one is nearby. I recommend to do this outside somewhere that you don't mind some oil mess. Placing a large drain pan under should capture most of the oil. I covered the valve with some heavy rags to capture the poppet as it is pushed out under pressure. If you drill it, be sure to drill in center so the flat sealing surface behind poppet is not damaged.

 

[Kmicah40]

Although not the safest or cleanest method, I have started the tractor and operated the valve briefly to pressurize and blow out the poppet. If you try this, be sure to stand out of the way and make sure no one is nearby. I recommend to do this outside somewhere that you don't mind some oil mess. Placing a large drain pan under should capture most of the oil. I covered the valve with some heavy rags to capture the poppet as it is pushed out under pressure. If you drill it, be sure to drill in center so the flat sealing surface behind poppet is not damaged.

Well that worked great. The poppet was in pretty bad shape. The new poppet was a bit different than the old one but worked out great. Thanks for your suggestion. Larry

 

[Zebrafive]

Might want to replace the one for the other spool too.

 

[Kmicah40]

Might want to replace the one for the other spool too.

I plan on replacing the other one as well. One other question. The attached photo shows the damaged poppet and the threaded plug. The other piece was in a groove just behind the threaded portion in the DSCV. Once the poppet was removed I found what looks like 1/2 of a seal or guide for the poppet to slide in. The poppet was in pretty bad shape, but have not figured out if the piece that was in the groove is needed any longer. The new poppet seems to work.
Thanks again for all your help.
Larry

 

[jd110]

There are no other parts shown in any diagrams in parts book or service manual. It may be a part of a seal from a cylinder packing of even a piece of the other poppet valve that has broken off.