TJ 225 Hydraulic Valve bank

[mf40diesel]

Hello all,

Some time ago I posted about my skidder  ('66 TJ) steering valve.  The steering valve spool when pushing the lever down (retracting the spool into the valve body) has a very sticky spot, to the point that one kinda has to really jerk it in there.  I kinda think that the steering articulation itself is a little slow too, although this is the only 225 I have ever run, so I might be out to lunch on that. (although that would go in line with a worn spool causing bleed by in the body)

I just recently purchased the o-ring kit from Harold's logging, perhaps an o-ring has "pooched," out and is jammed somewhere causing some issues.  With that said, it also could surely be a problem in the lower end of the spool (spring or guides) or with my luck it is probably the spool itself.

There is a local hydraulic shop that I will likely drop the whole valve bank to when I go back to work, and he can rebuild it.  They are super simple, but any guess what that might cost?

How about any idea where one could find rebuild valve banks for online?   Thanks very much

[bushmechanic]

Before you go and spend a lot of money on a rebuild, pull off the bottom cap of the spool. I have seen that oil seeping from the spool down into the cap will cause an hydraulic lock and make the spool difficult to move. Water can also cause this but will freeze in the minus temps and no movement of the spool happens then.

[Neilo]

Did you disconnect the linkage like I suggested? So you know it isn't the lever rod.

[mf40diesel]

Neilo,  I did take some of it apart, and I think i achieved what you were getting at at the time.  I removed the pin, connects the lever to the hydraulic spool.  With that out, the steering lever moved easily up and down, through it's full movement.

There wasn't quite as much room in there as I thought, and therefore I couldn't quite get any tools on it to throw any real pressure on it.  Sadly I am pretty sure the binding is associated with the spool itself in some way.

The guys on the ship here suggested that perhaps an o-ring was able to come out of a groove and cause it to bind up, however in looking at the drawing, it appears that the only o-rings are on the ends, so none could/should be able to get in the moving path of the spool. 

could be a broken spring or something, but I'm betting that the spool is worn which is allowing it to cock in there or somethign like that.  If one can't easily get a new spool, I wonder if you can just rotate it 180 and put it back in?  Might make it wear the opposite way?

I will surely take it apart before I take it anywhere that's for sure, looks pretty straight forward.  Could be just that simple.  Then if I have to, I will take it to the local hydraulic guy if I need to.  Seeing as its the steering, its super annoying.

thank you very much

[snowstorm]

spools to valve boar are only sealed by there precision fit. the orings only take care of what seepage that comes past the metal to metal fit. another thing that can cause the spool to move hard. on a old valve bank sometimes the chrome comes off the spool or it pits

[Puffergas]

Not about the sticky valve but about slow turning. My 225 needs it's engine revved up for it to turn faster.

[mf40diesel]

I'm excited to get home and take it apart.  I gotta get my tranny top cover back together first though.... unless by stroke of bad luck it's not done yet, then I will mess with the steering too!

I would assume that those spools are pretty readily available to a hydraulic guy?  Maybe not though.  I also hope that the spool itself is the wear part and not the valve body itself.

Thanks for the information.

[North River Energy]

I also hope that the spool itself is the wear part and not the valve body itself.

Those should be precision matched by lapping at assembly, so a replacement is most likely spool/body.
Hope for some kind of debris/obstruction in the end cap.

[mf40diesel]

Roger.....   must be grit / debris / broken spring in the bottom cap!

Thank very much

[mf40diesel]

As a quick update, not that anyone but me has been losing any sleep over it, but I have removed the valve bank from the machine.  Once I had it on my bench, I can move the spool up and down without any problems.  Took the spool out, looks pretty mint, alittle scuffing on one side, but totally straight.  I think the problem is the egg shaped hole where the lever attaches the spool. To get full movement of the spool, this causes one to move the lever farther than intended, which pulls it out of alignment, causing binding. 

I brought it the local hydraulic guy, perhaps he can drill out the spool to either bush it, and use the same pin, or accept a larger pin.  Or better yet, maybe a new valve section can be had relatively cheaply.

I'll keep you posted.

[bushmechanic]

The tolerances on the spool to valve clearances are pretty tight and it may be how the sections are bolted together. If they are a little off when you tighten down the valve assembly it can make it bind. To test this you could reinstall the valve and not tighten the bolts past finger tight and see if it works ok then.

[Mooseknuckle]

My blade on my 65 TJ was very slow to go down and it would not raise the front tires of my 230 off the ground. Pulling The lever up was no issue but pushing it down got worse and worse. I removed the entire valve bank. Picked up an O ring kit and took it appart on a bench. What I noticed was a lot of pitting on the chrome of the one spool.  I cleaned it all out, springs were intact changed most of the o rings and buffed the spool.  Put it all back together and no issues now. Moves full range up and down real fast and puts that front end right up in the air. I have all the pictures in my gallery and they are in a post that i submitted on the forum.   The guy at the hydraulic shop told me it would have cost a few bucks to get one of their guys to do the job.  Glad i took it on as it was easy!!  8) Good luck!!!!

[mf40diesel]

Thanks for the responses.  I'm pretty hopeful that the problem is not actually the spool itself (in relation to the hydraulics) but actually the way in which the lever linkage attaches to the spool. With the hole where the linkage pin so egg shaped, the lever runs out of travel before the spool is fully functioned, plus pulls out of alignment too, which exacerbates the problem.

We shall see.  Looking on ebay there is some new old stock cessna spools on there.  Fairly cheap.  How does one size valves?  Besides flow rate and pressure, the only other thing that I know is open vs. closed center hydraulics.

[mf40diesel]

Thought I would give an update, and pose a question.  I am not home yet, get there the end of this week.  My Dad picked up the valve bank from the hydraulic shop. He ended up drilling out that one spool/pin attachment and provided a pin one size larger.

Can't wait to reinstall and try it out.  Question for you folks though.....  Do I need to bleed anything when I reinstall it, or will use eventually bleed itself back to the tank?   I suppose I could keep the connections slightly loose, start it up and tighten them when I get a little fluid, not really sure if that is necessary or not though.

Thanks ahead of time.  I will post whenever I get it all together and try it out.  Can't wait.

[Puffergas]

It should work out on it's own. It's not like hydraulic brakes or clutch.