8n hydraulic still got me puzzled

Ok guys need some further guidance here. I had top clover off and pump out completely cleaned the case put new o ring and backup washer
on piston piston and cylinder bore were not perfect but did not look bad, no major scores or anything. Did not do anything to the pump except
to put in a new relief valve. Smashed my finger real good putting the top cover back on, lesson learned. Ok here is what it is doing. Lift will
raise a 5 foot bush hog all the a up when tractor is setting still, but not while moving. Also leaks right down when clutch is pushed or pto is off.
Took side cover off to check for leaks and saw nothing from top and just a few, maybe half a dozen,bubbles from where the relief valve is.
When' nothing is attached to lift arms, they start to lift when quadrant lever is moved a little from bottom position and continue to raise as lever
is moved up. But when bush hog is attached quadrant lever must be almost to the top before any movement occurs, then when lever is moved
about 2 inches to the lower position, bush hog is on the ground. Only works in the top 2 inches. Can't understand why lift will raise heavy load
while setting still, even at low engine speed, but will not lift unit very much while moving. Eventually it will raise enough to clear ground. Stop
tractor and it raises right up. Could this still be a pump issue? Sorry for the long narrative but had to explain what is going on. Thanks.
 
Randy........look under yer rite knee, that ain't a "flush" handle, thats a position select handle. UP fer position control, HORIZ fer draught (plowing) 2nd tip; yer PTO must be ON. That what makes the hydraulics work. Thats the lever in the LEFT hand 6-in roundy circle plate. 3rd tip; ennytime yer #12 clod-hopper is clomped down on yer clutch pedal, the PTO ain't turning and hydraulic pump ain't pumping. Isn't that amazing? So ennytime yer clutch pedal is pushed, or engine is OFF, yer hydraulic's ain't pumping and 'nuttin is gittin' lifted and will eventually drift down. Final thought, remove the 6-in roundy dipstick plate and with a flashlite look fer leaks. Might be a drip or two, butta stream is BAD news. Yer hydraulic lift cylinder is leaking. (thats that "O" ringy thingy you replaced, "thingy" technical term, eh?) As fer why yer brushhogg only lifts in top 2-in of quadrant, that's probably yer 3-point lift control lever external cork clutch. Needs tightening or replacement. Remember, MANDATORY ORC (over running clutch) on the PTO fer the brushhog, otherwize when you clutch to slow down to go around the corner of the barn or fence post or tree, the INERTIAL swinging weight of the BH BLADE will continue to drive yer tractor forward over the bank and into the creek. (or other obstacle) ........HTH, Dell, yer ORC safety preacher
 
Are you in position control? If so your cam follower pin is worn. Did you check that when you had the top cover off?
 
Ok guys I am not completely stupid. I do know the pto has to be on and I do know where the little handle thingy needs to be, in the up position. I did check for leaks by removing the cover and observing while pump is running and with it shut off. Very little if any coming from above. Did notice a few bubbles, maybe half a dozen, coming from the vacinity of the relief valve in the pump. Pretty calm in there really. I did check the cam follower pin when I had the top cover off. It was worn a little but not very much. Just don't understand why lift will work sitting still but not hardly at all when tractor is in motion.
 
Well, Hurt Randy, I don't expect those trying to help you figure it out think that you are stupid, but they, as myself, need to know all settings, and what possibilities have already been eliminated in order to assess and possibly offer other suggestions.
Without information, we are only guessing & that is not a good way to attack a problem. As for myself, I see no connection between motion/stopped tractor and lift or no lift. I will observe with interest.
 
Sorry guys just a little frustrated. Maybe I should have taken the pump all apart when I had it out, but not sure what to look for. I did take a
couple of the springs and stuff out of one side, under the Micky mouse ears, they looked ok. Didn't go any deeper. Is there anything on the top
cover regarding the linkage that could be causing the problem. Never had any of that apart yet. Probably need to get a gauge and see how
much pressure the pump is putting out. One thing, when the lift arms are all the way down with nothing attached, and the control lever all the
way down, the arms will begin to raise after the control lever is raised just a little and continue raising as the lever is pulled up. This seems
normal. But like I said earlier, with a heavy implement t attached the control lever must be almost to the top before the arms will raise much.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top