Question about log splitter on M6800

[rbargeron]

B,
In your original post you talked of splitting wood with this rig, with the only anomalous behavior ocurring at cylinder extremes. If you could center your splitter valve without the tractor's relief valve singing, then your splitter valve definitely does not have the closed center option installed. Ain't hydraulics fun? You'll figure it out.

 

[BSawyer]

Thanks again for the guidance! I'll plan on pulling what appears to be a pwr beyond sleeve with plug and check it out to see if it in reality is just functioning as a open center plug. I think I understand what you are both telling me that it can not be a "closed center" system because I didn't have any problem with the control lever in neutral...

And I'll get into the relief valve also, to inspect it. Probably won't get to it til later in the week, but I'll let you know what I find.

I may still swap it out for a new control valve, but right now I'm just trying to gain a better understanding.

I'm sure you can see from the earlier pics that I oughta replace the hoses too.

 

[MadReferee]

Thanks again for the guidance! I'll plan on pulling what appears to be a pwr beyond sleeve with plug and check it out to see if it in reality is just functioning as a open center plug.

There will be no sleeve in there because if there was you would effectively have a closed center system, ie. fluid would not be flowing in neutral and something would have to give, either a relief somewhere or the pump. It's simply a cap screw plug that closes the hole.

 

[BSawyer]

Well it looks like the standard cap plug was replaced with a short sleeve and small plug. It's not deep like the power beyond adapter sleeve.This pic shows the sleeve with the small plug removed

I mentioned in the past that there were three relief valve types and you can see them here: Valves

Mine is the type listed as "non adjustable", but it comes in two models or strengths, #31 = 500-1500, #32 = 1500-3000 according to this Parts List

I don't understand if these are somehow two stage or have some sort of adjustment I can't figure out. I didn't see any shims.

Actual picture of mine I suspect it doesn't have any user serviceable parts...

Not a real good pic, but looking inside the relief valve port, I don't see anything except the far end of the assembly

 

[MadReferee]

It looks like someone took the power beyond sleeve and shortened it to reopen the passage to the normal outlet. Probably couldn't find a plug for the threads on the casting so cutting the sleeve and plugging it with a standard thread size cap was their only option. Rube Goldberg at best.

 

[BSawyer]

Slightly better pics of the adapter sleeve: Angle 1 Angle 2

I've got a crescent wrench that fits it but due to other stuff in the way can't get the sleeve out for a better pic. I'll have to see if I can find a 1/2" drive socket to fit it.

I guess it shouldn't hurt to continue using the "make do" cap, but I'll write Cross Mfg to see if I can learn more about the relief valve and whether it is stuck or what.

 

[BSawyer]

Got the big socket, pulled it and took a pic.

As suggested, the p.o. appears to have cut off a PB adapter and plugged it: Pic here

I still don't know whether the relief valve on the Cross control valve is working or stuck, so I guess I still need to verify the relief valve isn't simply set too low on the M6800. Otherwise a problem will still exist if I pickup that LS3000 valve, recommended earlier.

I guess I need to get a pressure gauge to make sure the tractor is set up right. Hopefully I'll get a FEL sometime in the future, after the tractor is paid off so its possible I'll have need to use the gauge more than one time. I don't particularly like to buy tools for a one time use. Checked my MAC auto transmission pressure gauges and they don't go near high enough.

MadRef, would you recommend simply testing the tractor relief at one of the quick connect valves on the tractor or putting it inline on the high pressure line to the log splitter?

 

[ozzie tractor]

a lot of kubota remote valves are designed that when you dead head a ram, it will flick the remote lever into neutral, this is so when you are lifting a implement , when it is all the way up it stops lifting, its more a convenience thing. anyway i wonder if your valve is not returning all the way to neutral and sticking half way, stooping oil flow. does your tractor have another remote without the detent? if so use it and tie the lever into the flow position. try that.

 

[ozzie tractor]

hang on a second. take the couplers off the end off the hoses and throw them over the creek bank. replace them with new couplers, DO NOT USE THE BALL ENDED ONE'S. use the ones with the pointy end, they are much better. what can happen (and it catches you every time to i might add) is the couplers can slam shut the valve on the end when hit with a sudden pressure shock. will stop everything dead until you stop the oil flow throught the coupler (by moving the remote lever back to neutral). if i where a betting man i would have money on this

 

[BSawyer]

a lot of kubota remote valves are designed that when you dead head a ram, it will flick the remote lever into neutral, this is so when you are lifting a implement , when it is all the way up it stops lifting, its more a convenience thing. anyway i wonder if your valve is not returning all the way to neutral and sticking half way, stooping oil flow. does your tractor have another remote without the detent? if so use it and tie the lever into the flow position. try that.

I only have the one set of remotes, for now... And the male tips on the hoses do have the pointed tips. Thanks!

I'm no expert, and I appreciate the advice, but I'd think the relief on the CV should give way before the tractors. But I can't say exactly what is happening.

So I decided to quit guessing and determine the pressures for sure. I wanted to be able to test the tractor's relief by itself. But I also wanted to test with splitter connected. I ordered a gauge and thought something like this might work for both purposes.

I've read & gotten a lot of great advice here, and wanted to ask for a little more. Is there any reason why I shouldn't put this together with some TP and have a removable gauge? (1/2" quick releases at both ends, 5000 psi gauge with a reducer. )

I looked, but wasn't able to see if someone has already done this.