Could air cause this issue???

[/pine]

I have been running my splitter with a single spool open center valve for for 6 months with no problems...I built a log lift and replaced the single with a two spool open center valve and plumbed the two cylinders accordingly...

I am currently running the system off the auxiliary lines of a Ditch Witch...I am using two 20' 1/2" hoses to power the splitter etc...

Before I started the D.W. for the first time with the new valve/log lift...it raised the lift but then stopped...the cylinder would not move in either direction...likewise with the splitter cylinder...it is like the system is locked up...activating either of the spools the cylinders move a fraction and stop...and not necessarily in the direction they are supposed to according to the way the valve is engaged...

The new (log lift) cylinder was completely empty of fluid when I first started the D.W...I was able to get a lot of foamy air/fluid out by cracking the lines but the same issue remains...

I hooked up the new cylinder to my K_ubota and log lift works perfectly...

I am thinking that it (hopefully) just has to do with the 20' lines from the D.W....Is it possible that there is some air trapped causing the described problem???

I have removed the new valve and tested it to be sure it is working correctly...I'm at a loss...

 

[Bigfoot62]

All of the hydraulics working correctly on the DW? (hydrostatic drive, trencher, etc)

 

[bluebirdacres]

I have been running my splitter with a single spool open center valve for for 6 months with no problems...I built a log lift and replaced the single with a two spool open center valve and plumbed the two cylinders accordingly...

I am currently running the system off the auxiliary lines of a Ditch Witch...I am using two 20' 1/2" hoses to power the splitter etc...

Before I started the D.W. for the first time with the new valve/log lift...it raised the lift but then stopped...the cylinder would not move in either direction...likewise with the splitter cylinder...it is like the system is locked up...activating either of the spools the cylinders move a fraction and stop...and not necessarily in the direction they are supposed to according to the way the valve is engaged...

The new (log lift) cylinder was completely empty of fluid when I first started the D.W...I was able to get a lot of foamy air/fluid out by cracking the lines but the same issue remains...

I hooked up the new cylinder to my K_ubota and log lift works perfectly...

I am thinking that it (hopefully) just has to do with the 20' lines from the D.W....Is it possible that there is some air trapped causing the described problem???

I have removed the new valve and tested it to be sure it is working correctly...I'm at a loss...

New 20 foot lines??? Small orfice fitting in circuit to and from ditch witch?? Air in lines originally compressed but when filled with fluid,the motion is very very slow.

 

[/pine]

Thanks for the replies...
I had been using the 20' lines with the splitter....(they do not lay flat etc...they go over a pile of gravel)
The D.W. has no issues...it seemed to be putting out pressure and pumping fluid (had to keep adding fluid to the tank while trying to bleed air etc...)

My current plan is to hook the two working ends of the 20' lines together (no valve) and running the D.W. for a minuter or two...(that part is open center)...then I'm going to go back to the single spool and make sure the splitter works the way it did...before the lift/new valve was added...

open to any thoughts/insights...

 

[/pine]

I am still at a loss for what might be causing the problem...I have eliminated any air...

Both the cylinders work like they are supposed with the (original) single spool valve...but when I install the new (Prince Wolverine) two spool valve...I get the same issue...when a valve is activated a cylinder will move slightly then lock up and won't move in either direction...the hoses pulse but the cylinders won't move...

The valve is brand new (been sitting on a shelf for several years)...testing with forced air the valve seems to work as it is supposed to...

I have not checked the pressure on either of the working ports which I plan on doing next...Is it possible the pressure relief valve is causing this problem?...would a faulty relief valve cause the cylinders to lock up??

 

[muddstopper]

Are you using quick connects when hooking up the 20ft long lines. If so it could be possible that the QC are not fully engaged letting oil complete its circuit from pump to tank. another thing I would check is the valve to see if it is a power beyond valve. It could be possible that if PB, and has the PB sleeve in the port, it could be operating as a closed center valve. If this is the case, simply removing the PB sleeve would fix the problem. I do think if this was the case, you would feel the valve heating up as oil bypassed over the relief, and you would probably hear the pump and relief whinning, but not being there or seeing how its connected, its hard to say.

Let me expand on the possibility of the valve being power beyond capable and working as a closed center vavle. To work as a closed center valve, the PB port would have to have the proper sleeve installed inside the port and that port then plugged. Where the problem might lie would be in the plumbing of the valve. If the PB contains the sleeve and port is plugged, pressure would build up and dump over the relief since it has no path back to tank. The return line only allows oil to flow back to tank when the valve spool is shifted from center position. Now, if the PB port is sleeved and then the PB port is used to return oil to tank, and the normal return to tank port is plugged, the oil passing thru the valve while shifted would also have the oil path to tank blocked. this would cause the cyl to lock in position. with a multispool valve, and with no other valve connected thru the pb port, the PB sleeve should be removed, the PB port plugged and the return port plumbed back to tank, but with the PB sleeve removed, either the PB port or the return port could be used as return to tank oil flows. The sleeve is what seperates the two ports. I am just guessing and not knowing how you have the valve plumbed, but based on your cyl locking and not moving in either direction, I must think that oil isnt able to return to tank. If the valve works with one tractor but not the other, I would double check the QC fitting first and in the absence of the QC, I would then look at the valve. I would also chec to make sure I didnt have a line crossed going to the two cyl.

 

[Tx Jim]

I have not checked the pressure on either of the working ports which I plan on doing next...Is it possible the pressure relief valve is causing this problem?...would a faulty relief valve cause the cylinders to lock up??

A faulty relief valve could cause cyl not to get enough pressure therefore not move cyl rod.

 

[LD1]

Have you tried the kubota with the new 2-spool valve?

 

[/pine]

Again, thanks for the replies...
Yes I am using 1/2" QD's on the hoses...I have reseated them countless times...

When the D.W is running fluid is returning to the tank...when a valve is activate it does as I described and when the cylinder are locked up the D.W. slightly bogs down...

Yes this is a PB valve but the carry over plug is not installed...

I have not connected the new valve to the K_bota hydraulics...I only connected the splitter and the lift cylinders to the QD's on the K_ubota to make sure there was no issues with the cylinders...the valve installed on the K_ubota is identical to the one I'm having problems with...

What I first thought was happening after I quit thinking it was air in the system...is that there could be a problem with the spools...when a valve lever was activated it acted like fluid would flow to the cylinder but was not able to return...but I connected a clear hose between the two working ports...charged the system with forced air and could see air/fluid (that was still in the valve body) move in either direction depending on which way the lever was activated...and was returning to the tank line...

This afternoon I will put a pressure gauge on one of the working ports and see what the PR valve is doing...

FWIW...the D.W. puts out 9 GPM @ 2500...the valve is rated at 8GPM (3500) nominal...

 

[LD1]

Sounds like the valve you have has regen spools?

 

[/pine]

Sounds like the valve you have has regen spools?

No just standard open center 2 spool: 2 SPOOL 8 GPM PRINCE MB21BB5C1 DA VALVE

I had originally planned to use this valve on the K_ubota but got the same valve with a float detent on one of the spools for the tractor...

Have just now got a manifold put together so I can check pressures...will post results...

 

[muddstopper]

The valve you posted the link to comes with the PB plug standard, have you pulled the cap off port C and verified the plug isnt installed. Even if installed, if you have the return line connected to the out port, not the PB port, the oil should return to tank once valve is shifted, unless pressure build up is so great the valve isnt actually shifting. For the cyl to partially extend and not be able to fully extend or retract, oil going to return has to be blocked somewhere. Either spool not shifting or possibly broke, bad quick connect, crossed hyd line, or return line not properly plumbed or plugged. About all I can think of, but I am not an expert so it wont be the first time I have been wrong.

 

[/pine]

I have physically opened the port and verified there is no carry over plug installed (also still have the plug on hand)...

When no spool is engaged fluid is flowing through the valve properly from pressure side to tank...
...as verified with the clear hose mentioned in previous post...charging the pressure side with air a spool both pushes and returns and discharges via the tank port in both directions...

Now...after putting a gauge in a working circuit...I initially get 2500 in one direction but only get 2000 in the other...and the machine bogs a bit...adjusting the PRV seems to have no effect on these pressures...

another thing...when I first start the D.W....it moves a cylinder normally for a very short time then it locks up...again it acts like the fluid is not being able to return when the valve is engaged but testing with forced air it works fine...
Would/could the PRV be causing something like this...

am open to any ideas/suggestions...right now I'm looking for an old 2 spool Cross valve I have around here somewhere...!

 

[muddstopper]

Gauge in the pressure line going to the valve or in the working lines going to cyl. Pressure shouldnt build until cyl reaches full extend or retract. Yea you will see some pressure, but if all your doing is running the cyl in and out, and not hitting the limits of the cyl, I wouldnt expect to see those kinds of pressures. As for the PRV causing the cyl sticking, I wouldnt think so. The relief is allowing the circuit to build 2500psi which should be more than enough pressure to move the cyl. If relief was stuck open, you would see limited amounts of pressure because of oil flow, if valve was stuck closed, you would be able to see pressures up to the limit of the pump. Oil flow is what moves the cyl, not the pressure. Something has to be blocking oil flow to allow the pump to build the pressures you are seeing. You have verified the PB plug has been removed so oil blockage would have to be on the return side of the circuit. I am back to tripple checking the QC's. Maybe removing them completely just to make positive one of them isnt messed up.

 

[KWentling]

Are you very sure that you are supplying fluid in the correct direction through the new valve? Feeding it backwards can cause some strange things. Double check that you have the hoses to the cylinders in the correct position on the valve. Sure sounds like a plumbing problem to me.

Kim

 

[/pine]

Are you very sure that you are supplying fluid in the correct direction through the new valve? Feeding it backwards can cause some strange things. Double check that you have the hoses to the cylinders in the correct position on the valve. Sure sounds like a plumbing problem to me.

Kim

I have checked and quadrupled checked that plumbing/direction etc. is correct...I've had the long hoses clearly marked and they have not been disconnected from the D.W. from the onset...

The update is that this is not a valve issue...I have tried a second two spool valve with the same results...however when I reinstall the original single spool it works perfectly...splits wood fine...all the valves (the original and the 2 two spool valves) I have mentioned are open center...fluid passes from pressure side to tank side freely when no spools are activated...with all three valves I can hear/feel fluid flowing from P to T when spools are at center...I'm totally confused...considering starting a new thread since it seem so be a strange issue...I'm totally lost...

 

[/pine]

...I am back to tripple checking the QC's. Maybe removing them completely just to make positive one of them isnt messed up.

I have considered removing all the QD's just to be sure but I have used the same QD's between the original (working) single spool and the other two valves with no apparent issues...

 

[bluebirdacres]

Have any pictures of plumbing?

 

[KWentling]

I have checked and quadrupled checked that plumbing/direction etc. is correct...I've had the long hoses clearly marked and they have not been disconnected from the D.W. from the onset...

The update is that this is not a valve issue...I have tried a second two spool valve with the same results...however when I reinstall the original single spool it works perfectly...splits wood fine...all the valves (the original and the 2 two spool valves) I have mentioned are open center...fluid passes from pressure side to tank side freely when no spools are activated...with all three valves I can hear/feel fluid flowing from P to T when spools are at center...I'm totally confused...considering starting a new thread since it seem so be a strange issue...I'm totally lost...

I think you have hoses out of position. Both hoses from one cylinder have to go to the same spool or you you'd be locked up like it sounds like you are. One hose to port A and the other to port B. Same for the other cylinder. Pictures would help.

Kim

 

[aczlan]

I think you have hoses out of position. Both hoses from one cylinder have to go to the same spool or you you'd be locked up like it sounds like you are. One hose to port A and the other to port B. Same for the other cylinder. Pictures would help.

That would be my first guess. The hoses for each cylinder should line up with the valve handle. One near the handle and one away from it.
To test that theory, see what happens if you move both levers on the new valve at the same time (try both in the same direction and opposite directions)

Aaron Z