Could air cause this issue???

[muddstopper]

Chances of having two bad valves would be slim, but not unheard of. If your sure the QC are working properly, I am with KWenting, in thinking you might have a couple of hoses crossed, and I mentioned this early to check the hoses. If oil is passing thru both valves with spools centered, but cyl lock when spools are shifted, oil flow cant be returning to tank. Take both hoses off of one cyl, at the cyl not at the valve, and put ends in a bucket and then shift the valve for that cyl, both directions, and see what happens. Pics would help.

 

[/pine]

I agree the symptoms sound exactly like something is not plumbed correctly...and to be double sure there is not...I have set up the original single spool valve and made sure the splitter was working...I then moved the relative pressure and return lines to one of the two spool valves (no doubts about P&T/ IN/OUT ports)
I then moved the splitter hoses to one set of the working ports on the two spool valve...same issue regardless of the spool (working ports) I connect to...

BTW...the second two spool valve I have tried is a Cross industrial valve...all are open center, confirmed by open passage between IN and out ports when spools are centered...

it's a mystery (to me anyway)...

 

[/pine]

... If oil is passing thru both valves with spools centered, but cyl lock when spools are shifted, oil flow cant be returning to tank. Take both hoses off of one cyl, at the cyl not at the valve, and put ends in a bucket and then shift the valve for that cyl, both directions, and see what happens. Pics would help.

I will try this tomorrow if the weather permits...I thought I had eliminated this scenario by using the clear tubing and forced air...when a spool was activated air/fluid passed from one working port to the other and out the return port and vise versa with the lever moved the other way...but this was just with low pressure air and whatever fluid was in the valve body...it's truly a mystery...

Just for clarification if the WX permits tomorrow I will take any/all pertinent pictures to document the plumbing is correct...

 

[muddstopper]

Connecting the working ports with a hose, fluid should pass as you say, but if you mistakenly crossed the hoses between the two cyl, then you would have oil going to one end of one cyl and the other end of the other cyl and that would cause lockup. Very simple mistake and very easily done, I should know, I have a degree in getting hyd hoses crossed, the old saying If I had a dollar for everytime, well you know the rest.

 

[/pine]

Connecting the working ports with a hose, fluid should pass as you say, but if you mistakenly crossed the hoses between the two cyl, then you would have oil going to one end of one cyl and the other end of the other cyl and that would cause lockup. Very simple mistake and very easily done, I should know, I have a degree in getting hyd hoses crossed, the old saying If I had a dollar for everytime, well you know the rest.

This has not occurred...the splitter cyl has 1/2" hoses and the log lift cyl. has 3/8" hoses...

What I can't fathom is the fact that there should be no difference between an OC single port valve and and an OC two port valve in re...but even if I block off one (spool) set of working ports and connect one cyl...the same symptoms occur rather than the two spool valve working as a single...

it's a mystery....need some clues...!

 

[oldnslo]

/pine,
when operating your valve do either or both of the cylinder hoses look like they are being pressurized? I.E. they get stiff and swell? If both there is a restriction back to tank. If you only have two hoses to your DW where in the tank connection for the return oil from your cylinders going?

I am not familiar enough with the various valves to be 100% positive that on ALL models the PB and tank are common with out the PB plug. Thsy should be but a simple check would be to open the tank port and see what happens.

 

[/pine]

/pine,
when operating your valve do either or both of the cylinder hoses look like they are being pressurized? I.E. they get stiff and swell? If both there is a restriction back to tank. If you only have two hoses to your DW where in the tank connection for the return oil from your cylinders going?

I am not familiar enough with the various valves to be 100% positive that on ALL models the PB and tank are common with out the PB plug. Thsy should be but a simple check would be to open the tank port and see what happens.

Yes...after the cylinders lock up (after a slight initial movement) when the spools are engaged the hoses pulse...there is definitely pressure there and the D.W. bogs...

As I have related and others have too...it's like when a spool is engaged the fluid is not being allowed back to the return but why?

 

[/pine]

Just for the record...when I originally hooked the 20' hoses to the D.W....I marked the pressure line on both ends with red vinyl tape on both ends so there would never be any doubt or possible mix up (then I installed the return line) likewise I reverse the QD's (M/FM-IN/OUT)...when setting up the valves I mark the IN/pressure port with the same red tape...I have been meticulous in making sure this not a simple plumbing issue...

So what can it be...?

 

[/pine]

Sounds like the valve you have has regen spools?

Please look over my posts since the above...Your query has come back to me since in trying to realize what could be the difference between the original single spool OC valve (that works fine) and a typical two spool OC valve...?

What are "regen" spools? and if the original single spool valve had said "regen" spools and the two spool valves do not...could this make a difference?

When I say "original" single spool valve...I mean an auxiliary valve that had been set up on the DW (OEM) for a horizontal boring attachment...I merely moved the valve to the splitter (homemade, been working great for 6 months) and after designating the *lines* I added QD's and connected the DW with the 20' 1/2" hoses...

* The "lines"...the pressure line comes from a pressure block that also has large (1" QD) pressure port for the backhoe and a PB port as well as a return QD...the return line from the "original" single spool valve directs to the bottom of the tank...

 

[/pine]

Just an off the wall question in reference to/with information I have posted above...

Is there any reason I cant/shouldn't disconnect the return at the DW open the end (plug the original retrun) and just stick the end of the 20' return line in the reservoir fill port and have someone watch and see if fluid is returning when a spool is engaged? and if not why?

 

[LD1]

I see no reason why you cant put the return hose in a bucket and watch for fluid. Just make sure the hose dont jump out of the bucket.

A regen spool only effects one direction of motion. And what that does is pressurize BOTH the A and B ports. With pressure at both ports the cylinder can ONLY extend because of piston area difference. And when it does, it does so quickly. Regen is for faster cycle speed but lower force/tonnage. You are only having to pump in new fluid to make up the area of the rod, and not the whole cylinder bore.

If a regen valve is installed backwards, with regen function on retract instead of extend, while trying to retract the cylinder (in regen mode) it will extend instead. So no matter which direction you push the valve, it will extend. But a regen valve usually has a detent or two positions where either pushing the valve further (or not as far) is normal NON-regen mode.

The loader joystick on your kubota should be this way for curl. Push a little to dump is regen, all the way to dump is normal mode. Most aftermarket valves I have seen have regen in the second position. So as you are pushing the valve to retract the cylinder, it will start to move a little because first position is not regen, but continue pushing the lever and enter regen mode and you have a cylinder locket at full extension and trying to extend more.

but the spool you linked isnt listed as a regen valve. Typically the end of the spool where the handle is connected will have a R stamped into it, but not always. And you should have noticed this on an air test anyway.

 

[/pine]

I see no reason why you cant put the return hose in a bucket and watch for fluid. Just make sure the hose dont jump out of the bucket.

A regen spool only effects one direction of motion. And what that does is pressurize BOTH the A and B ports. With pressure at both ports the cylinder can ONLY extend because of piston area difference. And when it does, it does so quickly. Regen is for faster cycle speed but lower force/tonnage. You are only having to pump in new fluid to make up the area of the rod, and not the whole cylinder bore.

If a regen valve is installed backwards, with regen function on retract instead of extend, while trying to retract the cylinder (in regen mode) it will extend instead. So no matter which direction you push the valve, it will extend. But a regen valve usually has a detent or two positions where either pushing the valve further (or not as far) is normal NON-regen mode.

The loader joystick on your kubota should be this way for curl. Push a little to dump is regen, all the way to dump is normal mode. Most aftermarket valves I have seen have regen in the second position. So as you are pushing the valve to retract the cylinder, it will start to move a little because first position is not regen, but continue pushing the lever and enter regen mode and you have a cylinder locket at full extension and trying to extend more.

but the spool you linked isnt listed as a regen valve. Typically the end of the spool where the handle is connected will have a R stamped into it, but not always. And you should have noticed this on an air test anyway.

Thanks for the explanation...What I'm wondering is what could be the difference between the original single spool and the two spool valves that would cause the issue I'm having...

Actually when the cylinders are locked up and the lever is activated the rod seems to slightly pulse in both directions regardless of the way the lever is moved...

We have a brutal wind chill here today...not sure I will get a chance to check the return...

Right now I am considering using the hydraulic connections that are hooked to the backhoe and disregard the auxiliary lines I'm using now...

 

[muddstopper]

Pine, right now, you are 100% positive everything is connected correctly, but its still not working like it should. You have tried two different 2 spool valves and have the same problem. What are the chances of having two valves that are bad with the same exact problem. I dont really have anything else I can add, except maybe revisit everything. I still am inclinded to think that you have a line crossed somewhere. I certainly want to know what the problem is when you find it.

 

[LD1]

Whenever the weather breaks, I think some pictures are in order here

 

[/pine]

At this point I am truly at a loss...

As I have said before when I originally connected the two 20 1/2" hoses to the DW I clearly marked the pressure line before I ever ran the return hose to the DW...

Connecting the original valve and making sure the splitter is working...I've shut it down and connected the lines to one of the two spool valves (set up as a single spool with steel plugs in the other two working ports) same issue with the single cylinder...this is the conundrum...

Before I resort to abandoning the auxiliary lines and using either the PB or the backhoe ports...I'm going to remove all the QDs just to make sure...but I have been using the same QDs on the original (working) valve...Also...with either of the two spool valves...I've connected the log lift cyl. without QDs...same issue...!

I don't mind posting some pics but I'm not sure what it would accomplish...there is virtually no way I can be crossing or mixing up the lines when I just move them from the original working single spool to one of the two spool valves...I can place them side by side and methodically make sure they are connected correctly...

 

[bluebirdacres]

At this point I am truly at a loss...

As I have said before when I originally connected the two 20 1/2" hoses to the DW I clearly marked the pressure line before I ever ran the return hose to the DW...

Connecting the original valve and making sure the splitter is working...I've shut it down and connected the lines to one of the two spool valves (set up as a single spool with steel plugs in the other two working ports) same issue with the single cylinder...this is the conundrum...

Before I resort to abandoning the auxiliary lines and using either the PB or the backhoe ports...I'm going to remove all the QDs just to make sure...but I have been using the same QDs on the original (working) valve...Also...with either of the two spool valves...I've connected the log lift cyl. without QDs...same issue...!

I don't mind posting some pics but I'm not sure what it would accomplish...there is virtually no way I can be crossing or mixing up the lines when I just move them from the original working single spool to one of the two spool valves...I can place them side by side and methodically make sure they are connected correctly...

Could the load checks on the valve cause problems? I'm not sure how they work, maybe someone that does can chime in. Are load checks on both the extend and retract ports? Not suited for this application? Need special hookups? Just asking, noticed it when I looked up the valve listed.

 

[KWentling]

At this point I am truly at a loss...

As I have said before when I originally connected the two 20 1/2" hoses to the DW I clearly marked the pressure line before I ever ran the return hose to the DW...

Connecting the original valve and making sure the splitter is working...I've shut it down and connected the lines to one of the two spool valves (set up as a single spool with steel plugs in the other two working ports) same issue with the single cylinder...this is the conundrum...

Before I resort to abandoning the auxiliary lines and using either the PB or the backhoe ports...I'm going to remove all the QDs just to make sure...but I have been using the same QDs on the original (working) valve...Also...with either of the two spool valves...I've connected the log lift cyl. without QDs...same issue...!

I don't mind posting some pics but I'm not sure what it would accomplish...there is virtually no way I can be crossing or mixing up the lines when I just move them from the original working single spool to one of the two spool valves...I can place them side by side and methodically make sure they are connected correctly...

We are operating blind here. All we have to go on is what you are telling us. I'm 99% sure it is plumbed wrong. If we had pictures, someone here is likely to be able to spot the problem. Pictures of the original valve along with the new valve plumbed in would be a huge help to us blind people. Short of that, all I can suggest is you start over with the plumbing, Start with the Ditch Witch hoses in a bucket and verify which hoses is the supply. Get the valve instructions out or look at the PDF at the link you posted, and follow it to a tee. I'll bet it works. My 1% doubt is we know nothing of the Ditch Witch hydraulic system supplying this.

Kim

 

[/pine]

We are operating blind here. All we have to go on is what you are telling us. I'm 99% sure it is plumbed wrong. If we had pictures, someone here is likely to be able to spot the problem. Pictures of the original valve along with the new valve plumbed in would be a huge help to us blind people. Short of that, all I can suggest is you start over with the plumbing, Start with the Ditch Witch hoses in a bucket and verify which hoses is the supply. Get the valve instructions out or look at the PDF at the link you posted, and follow it to a tee. I'll bet it works. My 1% doubt is we know nothing of the Ditch Witch hydraulic system supplying this.
Kim

First I appreciate all the replies and thoughts...I fully understand the difficulty in trying to give advise from the blind side and rely on verbiage...I have tried to articulate the exact circumstances...

To say again...the two 20' hoses have been connected to the DW since July...I have been splitting wood weekly since then without ever (other than resetting the QDs) disconnecting them...both the lines from the DW (previously connected to the "original valve") are clearly marked (red for pressure)...all I did was move the valve and extend the hoses (20')...the system still splits wood fine with the original valve...

Below is a pic of the original and the Cross valve...they are set up for testing so the configuration of the connection ports may seem odd...all the valves are clearly marked for P/IN T/OUT and plumbed accordingly...

I still have to think there is "something" different about the two spool valves and the original even though they are all OC valves (fluid is always flowing them when connected)

 

[KWentling]

Thank you for the picture. Are the 2 male fittings on the left going to one cylinder, and the 2 female swivels on the right going to the other? If so that looks good (other than the teflon tape). If the red tape is on the supply in, then that's good too. What's going on with the back to tank side? It looks like a tee there? You want to avoid using galvanized pipe in hydraulic systems because it can shed galvanizing and damage pumps and valves.
Teflon tape is not recommended because of stray tape clogging suction screens, filters, and it can cause problems with valves sticking. If you leave the first thread bare, it won't be a problem until you take it back apart and reuse it without getting all the tape cleaned out. None of that is causing your problem though.

Kim

 

[/pine]

Thank you for the picture. Are the 2 male fittings on the left going to one cylinder, and the 2 female swivels on the right going to the other? If so that looks good (other than the teflon tape). If the red tape is on the supply in, then that's good too. What's going on with the back to tank side? It looks like a tee there? You want to avoid using galvanized pipe in hydraulic systems because it can shed galvanizing and damage pumps and valves.
Teflon tape is not recommended because of stray tape clogging suction screens, filters, and it can cause problems with valves sticking. If you leave the first thread bare, it won't be a problem until you take it back apart and reuse it without getting all the tape cleaned out. None of that is causing your problem though.

Kim

There are no T's...I did use one galv. bushing (low pressure side) in a pinch for testing the Cross valve all the rest are steel...I am aware of the teflon tape debate and am always careful to hold it back...and when reusing anything I clean them carefully...

The two male fitting are JIC connectors for the two 3/8" lift cyl. hoses...the swivel connectors are 1/2" pipe...I was not using QDs on the lift cyl... by reversing the gender of the QDs on the valve and on the pressure and return lines (20' hoses) I have eliminated the possibility of a mix up...

I will try to snap some pics of the DW, hoses and splitter/lift cylinders tomorrow...