863 F Series High-Flow with Aux Hydraulics Problem

[Motordoc]

Great oracles of the SkidSteer Forum...I have a mystery....Looking for a little help as I am stumped..... I have a 1998 High-Flow 863 with an 811 backhoe attachment and the aux hydraulics will not lock. The momentary and lock LED's turn on and I noted that when the momentary LED was on only the thumb switch would activate the hydraulics moving the switch to the left....moving to the right...nothing...no sound no hydraulic pressure...this of course being the controls on the right hand side. I switched the connectors to the solenoids and was able to activate the hydraulic "lock" using the trigger....yet the backhoe attachment would "dead head". After some checking I confirmed that BOTH solenoid coils work as I switched solenoids and moved each to the "electric solenoid valve" (some folks call these stems) that was working. Additionally I flipped the electrical connectors to the solenoids to verify that the momentary thumb switch works in both directions.....it does. As a final step, I moved the "electric solenoid valve" (stems) from the non working side of the Hydraulic Control Valve to the other...it worked when switched to the previously working side of the Control Valve. I did note one odd thing, when referencing the Bobcat Service Manual, I cannot pull out the "Auxiliary Spool" from the non working side of the Control Valve once the Auxiliary Spool Cap is removed along with the centering springs....the spool seems to hit something inside of the Control Valve. Any ideas? A free mystery gift for the person who helps me solve this one!!!! Albert

 

[Motordoc]

I may be close to the solution.... As I noted in my post, the Aux Spool will not come out of the main control valve body using little force...I do not want to apply too much force. I have not tried to remove the auxiliary spool from the other end of the hydraulic control valve body.... any ideas as to what might be blocking the spool? There are no O-Rings on this spool.

 

[Tazza]

I may be close to the solution.... As I noted in my post, the Aux Spool will not come out of the main control valve body using little force...I do not want to apply too much force. I have not tried to remove the auxiliary spool from the other end of the hydraulic control valve body.... any ideas as to what might be blocking the spool? There are no O-Rings on this spool.

I have never pulled one out, but i believe the spool should slide out. I wonder if it is because there is oil at the ends that can't escape, did you remove the stems first?

 

[Motordoc]

I have never pulled one out, but i believe the spool should slide out. I wonder if it is because there is oil at the ends that can't escape, did you remove the stems first?

Looks like my aux spool is binding in the valve body... I removed both end caps and the spool will slide slightly side-to-side and then "snags" on something. Would anyone on the forum have a image of the control valve body showing the internal channels?

 

[Tazza]

Looks like my aux spool is binding in the valve body... I removed both end caps and the spool will slide slightly side-to-side and then "snags" on something. Would anyone on the forum have a image of the control valve body showing the internal channels?

There should be just a cap with a spring under it. What happens if you rotate the spool 90 degrees and see if it still snags while trying to remove it. I wonder if a metal particle is stuck in there binding it up.

 

[Motordoc]

There should be just a cap with a spring under it. What happens if you rotate the spool 90 degrees and see if it still snags while trying to remove it. I wonder if a metal particle is stuck in there binding it up.

Tazza...correct each end cap secures an inner and outer return spring...there is also a retainer that sits at the end of the springs and rests against the aux spool. I did try to slowly rotate the aux spool to see if the material would move and allow the spool to come out...no luck. I was thinking of going down through the electric valve port with a magnet to see if that would work relative to removing any metal particles...this is why I was asking if any members had "some type of cut-away image" of the Control Valve body to determine if the electric valve ports allow access to the aux spool chambers....just a thought. In the end, it appears that I need to remove the Hydraulic Control Valve. I do not want to force the aux spool through the valve body as I am sure this will score the spool...or worse. I guess the silver lining, if any, is that I will have a chance to replace the seals/O-rings on the rest of the control valve.....

 

[Tazza]

Tazza...correct each end cap secures an inner and outer return spring...there is also a retainer that sits at the end of the springs and rests against the aux spool. I did try to slowly rotate the aux spool to see if the material would move and allow the spool to come out...no luck. I was thinking of going down through the electric valve port with a magnet to see if that would work relative to removing any metal particles...this is why I was asking if any members had "some type of cut-away image" of the Control Valve body to determine if the electric valve ports allow access to the aux spool chambers....just a thought. In the end, it appears that I need to remove the Hydraulic Control Valve. I do not want to force the aux spool through the valve body as I am sure this will score the spool...or worse. I guess the silver lining, if any, is that I will have a chance to replace the seals/O-rings on the rest of the control valve.....

Sadly, the only images i have of the valve are a disassembled state, no internals to show where the chambers are. Hopefully with it out, you can remove everything and blow air and solvent through the ports and hopefully dislodge whatever is in there.

 

[themotordoctor]

Sadly, the only images i have of the valve are a disassembled state, no internals to show where the chambers are. Hopefully with it out, you can remove everything and blow air and solvent through the ports and hopefully dislodge whatever is in there.

Problem solved..... I was able to remove the aux spool valve with some modest pulling/twisting force. It appears that the edges of the spool valve sections developed very minor burrs over time which resulted in the aux spool valve catching on the master control valve bore...thus preventing the aux valve from moving side-to-side. To fix this, I put the spool valve on my lathe and took a very fine file and rounded the edges of each section of the spool valve ever so slightly....worked great and now the aux spool valve slides easily without snags....and my aux hydraulics work great.

 

[Tazza]

Problem solved..... I was able to remove the aux spool valve with some modest pulling/twisting force. It appears that the edges of the spool valve sections developed very minor burrs over time which resulted in the aux spool valve catching on the master control valve bore...thus preventing the aux valve from moving side-to-side. To fix this, I put the spool valve on my lathe and took a very fine file and rounded the edges of each section of the spool valve ever so slightly....worked great and now the aux spool valve slides easily without snags....and my aux hydraulics work great.

Odd that the spool developed burs, but glad you got it sorted out.
I should check my S250 out to see if it has the same issue. It has vairable flow, but only works on or off, may be the same sort of problem.