801 Hydraulic headache!!

[Scottymudguy]

60' 801...
Drained & cleaned out sump, re-built pump, replaced ring & backing ring on cylinder piston, replaced the position control shaft (Thanks to Mr. John Smith!! Who happened to have one.)Re-assembled everything & re-installed lift cover...ok sounds pretty straight forward to here right? Now lets go around the bend....
Fire the tractor up, warm it up good because its pretty chilly here in N.Nevada right now! When the hydraulic's come to life FINALLY...the arms come up....and stay up, not even after tractor is turned off can I get them to go down....put position lever down & stood on the arm's...nope aint going nowhere!
So off comes the cover again..this time with a hoist & a strap to keep her level...much easier!!
At first the cylinder piston still would not go back in, I ran a little air through the pump pressure side & finally got things moving...I'm not sure if I was "air locked" or if it was a slug of cold hyd fluid that just plain 'ol wasnt going anywhere! Anyone have thought's or experince like this? Next up...all this stuff is over the course of not quite 2 weeks...in the midst of all of it I had found links for Zane & his Thang!! Contacted him, he sent goodies & off to hydraulic adventure land I went.
So yesterday was when the cover had come back off & the whole cylinder piston thing takes place ( I was just dang glad that there was nuttin busted, broke, tweaked, ------ away..etc).
After I had my arms freed back up I went on to adjusting the linkages with Zanes materials & info..no problem, it went really smooth, quick, & easy...I would say under a half hour...& I was taking my time being very cautiuos & double checking everything. I wanted to ensure I had not missed or skipped nothing you know!!
So after all said & done, I put a little air to 'er to test things out...for some reason my position control lever has no bearing on what the arms are doing. Lever down, air, arms go straight to the top without me even touching the lever...Bled everything off (I clamped a rag over the return side hole to free up a hand...that worked great)& reset the arms back down, & tried holding them down this time while putting the air to it...nope aint no way, would have picked me up if I had both hands on 'em! So in streak of brilliance...I think "huh, my lever is "backwards"". So I moved the lever up and ran through everything again &......Got the same results...no diffrence!
Draft lever is in postion control the entire time during this by the way! Tried draft mode....same!!! Had to quit...thought about trying some reverse barley-pop engineering on it...probably a good thing I didnt, because a big hammer usually finds it's way into the scenario....
So questions I have..
1) Anybody have the "locked up" Cylinder piston like I described, before?
2) Is it possible I have linkages or shafts backwards? It all works smoothley & free, looks to me like the pic's I have seen of them
3) Valves or something stuck, or tore up inside the side of the lift cylinder?

Better take some Migrane stuff this morning....ey,yi, yi!!!

Scott

 

[JMOR]

(quoted from post at 14:01:41 02/27/11) 60' 801...
Drained & cleaned out sump, re-built pump, replaced ring & backing ring on cylinder piston, replaced the position control shaft (Thanks to Mr. John Smith!! Who happened to have one.)Re-assembled everything & re-installed lift cover...ok sounds pretty straight forward to here right? Now lets go around the bend....
Fire the tractor up, warm it up good because its pretty chilly here in N.Nevada right now! When the hydraulic's come to life FINALLY...the arms come up....and stay up, not even after tractor is turned off can I get them to go down....put position lever down & stood on the arm's...nope aint going nowhere!
So off comes the cover again..this time with a hoist & a strap to keep her level...much easier!!
At first the cylinder piston still would not go back in, I ran a little air through the pump pressure side & finally got things moving...I'm not sure if I was "air locked" or if it was a slug of cold hyd fluid that just plain 'ol wasnt going anywhere! Anyone have thought's or experince like this? Next up...all this stuff is over the course of not quite 2 weeks...in the midst of all of it I had found links for Zane & his Thang!! Contacted him, he sent goodies & off to hydraulic adventure land I went.
So yesterday was when the cover had come back off & the whole cylinder piston thing takes place ( I was just dang glad that there was nuttin busted, broke, tweaked, ------ away..etc).
After I had my arms freed back up I went on to adjusting the linkages with Zanes materials & info..no problem, it went really smooth, quick, & easy...I would say under a half hour...& I was taking my time being very cautiuos & double checking everything. I wanted to ensure I had not missed or skipped nothing you know!!
So after all said & done, I put a little air to 'er to test things out...for some reason my position control lever has no bearing on what the arms are doing. Lever down, air, arms go straight to the top without me even touching the lever...Bled everything off (I clamped a rag over the return side hole to free up a hand...that worked great)& reset the arms back down, & tried holding them down this time while putting the air to it...nope aint no way, would have picked me up if I had both hands on 'em! So in streak of brilliance...I think "huh, my lever is "backwards"". So I moved the lever up and ran through everything again &......Got the same results...no diffrence!
Draft lever is in postion control the entire time during this by the way! Tried draft mode....same!!! Had to quit...thought about trying some reverse barley-pop engineering on it...probably a good thing I didnt, because a big hammer usually finds it's way into the scenario....
So questions I have..
1) Anybody have the "locked up" Cylinder piston like I described, before?
2) Is it possible I have linkages or shafts backwards? It all works smoothley & free, looks to me like the pic's I have seen of them
3) Valves or something stuck, or tore up inside the side of the lift cylinder?

Better take some Migrane stuff this morning....ey,yi, yi!!!

Scott

our touch control lever controls the hydraulic-'switching' of 2 circuits, 1) it can dump the lift cylinder for lowering of arms, 2) it can send fluid to the large side of the unloader valve actuating piston. Neither of these two actions alone will result in the lift ram receiving fluid to raise the lift arms. However, when the unloader valve moves to the lift position, it blocks the backpressure valve's bleed-off, thus allowing pressure to rise & cause the lift ram to move, thus raising the lift arms. Now, when you return your touch control lever to a position of 'hold' or 'lower', the unloader vavle should return to its position of allowing the bleed-off via the backpressure valve. If by chance the unloader fails to move back to the 'hold'/'lower' position, then any applied pressure will act to cause the lift ram to raise the arms. Have you probed the hole that allows you to tell whether or not your unloader valve is moving among its two positions? Probably should.

 

[Scottymudguy]

JMOR,
I have never posted a picture here but I think I have 2 attached to this. They are I belive the ends of the unloading valve.
If they dont show up, the unloading valve is the one underneath the cover that the lift control valve passes through correct?
If so, then yes it is moving back & forth in there, but it does not spring back to one end or the other as I noticed it.
What you are saying is that it should go to one end when the control valve is activated, say in the "up" motion, & then back to the other end when the "down" motion is engaged if i am following your reply correctly?

 

[Scottymudguy]

Ok good the picture's showed up, I did see it sticking out of the hole above and to the left of the lift control valve in the top picture a couple times today. I know 1 time I just kinda pushed it in a little with my finger, it slid back into the body quite easily. But I of course cant remember where the postion control was at!!

 

[JMOR]

(quoted from post at 20:54:06 02/27/11) Ok good the picture's showed up, I did see it sticking out of the hole above and to the left of the lift control valve in the top picture a couple times today. I know 1 time I just kinda pushed it in a little with my finger, it slid back into the body quite easily. But I of course cant remember where the postion control was at!!

ounds correct. No spring. No mechanical connection. Hydraulic pressure will move it toward the hole in your first picture when lift is commanded. Otherwise pressure on it is dumped & a small pressure on the other side of its piston will move it away from that hole.

 

[Scottymudguy]

Ok Thanks...its catching the return pressure inside the body on this side of the piston head, then when pressure is applied it is catching pressure from the "back side, or the end of the second picture, correct? Or am completly backwards?

 

[JMOR]

(quoted from post at 21:20:56 02/27/11) Ok Thanks...its catching the return pressure inside the body on this side of the piston head, then when pressure is applied it is catching pressure from the "back side, or the end of the second picture, correct? Or am completly backwards?

hose words don't really fit my head. (This is hundred series hyd diagram.) When I speak of piston moving the unloader valve, I mean the part that the unloader valve arrow is pointing to. Obviously when this moves it moves the right hand control portion of the valve. Because of the mechanical connection on the right hand side of "arrow marked" piston part of the unloader valve, that side has a net area for pressure to act on that is smaller than net area of left hand side. So if pressure is equal on both sides, it will move toward the right (rear of tractor, during lift), but if pressure is dumped from left hand side, the valve assembly will then move toward the left (front of tractor). Does that help?

 

[Scottymudguy]

Jmor,
Sorry about bailing on you there...the dinner bell rang & Mrs dont take kindly to "hold on I'm in the middle of something"!!! Yes what you are saying makes sense to me now, I knew one of us was thinking backwards!! Me as usual!
So tomorrow I need to go down there and function test everything again & pay close attention to what that unloader is doing. It most likely is my culprit from what I am seeing...between your drawing's & mine that is.
Suspect the O-ring is either...
A) Gone
B) Split
C) wore out so fluid is leaking "over" it...or around I guess would be a better way to say it.
Think my last suspect in the unloading valve would be the bushing on each end of it...they I would think have some sort of a hard seat in/on them to prevent them from washing out or eroding with fluid moving past them...in fact now that I am re-reading this...I know for sure that the rear pointing end of it isnt washed out...I would have seen oil coming out of there today if it was.
Looking at the drawing u posted (found it on 384 & 385 in my book) Starting with releif valve in bottom left side..its the one in the very bottom of the sump, Control & Unloading valves on cylinder, Check is the one in the leading edge of the cover, Ram cyl sfty valve is the one on top of the cylinder when cylinder is out, Back pressure valve...I'm not sure I have seen that one, is it under the opt'nl remote cover?

Again thanks for the help guidance!!!

Scott

 

[JMOR]

The check & backpressure are both stacked behind that plug in the leading edge of lift cover. One behind the other.

 

[Scottymudguy]

Oh..Ok that makes checking two out pretty easy then...I probably better have a look at them as well whilst doing this I think!
What are the chances of the bore that the unloader rides in being my problem? That just hit me!!
looking at another drawing the control valve bushing looks to me like the control valve rides inside it...if thats the case would the unloader operate similar or the same..unloader operates insde the bushing's?
I think I see light!!! I can be a little dense from time to time!!