NAA Lift acting crazy

larry99sd · Jun 3, 2014

Working on this for a friend, Lift wouldn't really work much at all, noticed fluid pouring out around piston so removed cover and replaced oring and leather, and related gaskets and orings. Long story but also fixed water contaminated leak from trans into center housing. Back together with correct/clean fluid. Lifted fine but appeared to me that the piston was coming too far out of cylinder. I thought maybe that is why piston oring was cut, so I removed cover and adjusted rod to limit that, now it goes all the way up when first started, regardless of control handle position and sometimes won't respond up or down, very weird. I've bled system with hose. I really need some direction on adjusting this thing right. I have manual 19 but don't have the tools shown to make the adjustments shown. Thanks for any help. I'm a very experienced Auto Mechanic Senior Master with Ford and ASE, but I'm feeling pretty dumb right now.

larry99sd · Jun 3, 2014

I'm not sure if my adjustment caused this or not as I have never seen it work before. I noticed it also bleeds/creeps down with weight on it. I assume the control valve and bushing could cause this. Not sure where to air check this if I take it back apart so I can see how it functions without putting it all back together. I did get a little smarter and fixed a angle bracket to pick this cover up real easy with chain hoist.

JMOR · Jun 4, 2014

(quoted from post at 22:58:08 06/03/14) I'm not sure if my adjustment caused this or not as I have never seen it work before. I noticed it also bleeds/creeps down with weight on it. I assume the control valve and bushing could cause this. Not sure where to air check this if I take it back apart so I can see how it functions without putting it all back together. I did get a little smarter and fixed a angle bracket to pick this cover up real easy with chain hoist.

djusting the lift linkage to set or limit piston travel likely destroyed the DRAFT & POSITION control adjustable settings. Those need to be reset according to manual. Those "special" tools do very simple functions of positioning lift arms at 1/2 inch above the cover gasket plane during adjustments (just a bit above fully lowered) & any 'stepper' ought to be able to accomplish that without the 'special' tool. The other is a simple feeler gauge 3/16" for Draft & 1/4" for Position control.....think scrap metal/old bolts/grinder/file/calipers.
Applying air: same place that fluid comes into top cover from below (near left front corner). Need to be above the opening pressure of the check valve for this to work (~115 PSI).

larry99sd · Jun 4, 2014

Thanks a lot for the measurements, wish those were in the book. The fluid comes in this cover in the RF area of the cover but it's just a hole, so not sure how to get that much pressure on it with a rubber tip. thanks so much for your advice.

JMOR · Jun 4, 2014

(quoted from post at 09:35:09 06/04/14) Thanks a lot for the measurements, wish those were in the book. The fluid comes in this cover in the RF area of the cover but it's just a hole, so not sure how to get that much pressure on it with a rubber tip. thanks so much for your advice.

eah,..........I meant my"other left".

You will be surprised what you can seal with the rubber tip blow gun!

larry99sd · Jun 4, 2014

Ok, back to work on the tractor, I was waiting for a voltage regulator for the alternator, (got that fixed). It seemed like lift was working just fine in the shop, so I got to thinking, I did have a heavy trailer on it the other day when it was acting up. Put trailer on, drove around, moving it up and down, was working fine, then all of a sudden (after it warmed up good I think), It wouldn't respond to the the control up or down, so I left it up, (tractor is sitting still) after about 10-15 seconds it started creeping up and wouldn't stop, even with control handle all the way down untill it hit the top and reliefed, then went down and started working normal again. I can let it sit running and with handle up about 3/4 of full up position somtimes it will start creeping up and there is nothing you can do about it until it finishes it's cycle of the piston hitting that pin and reliefing it. It doesn't move at all in draft position, that is what I adjusted the other day (wrong). I'm not sure what to think about this mystery. Trash in a valve?

JMOR · Jun 5, 2014

(quoted from post at 22:01:13 06/04/14) Ok, back to work on the tractor, I was waiting for a voltage regulator for the alternator, (got that fixed). It seemed like lift was working just fine in the shop, so I got to thinking, I did have a heavy trailer on it the other day when it was acting up. Put trailer on, drove around, moving it up and down, was working fine, then all of a sudden (after it warmed up good I think), It wouldn't respond to the the control up or down, so I left it up, (tractor is sitting still) after about 10-15 seconds it started creeping up and wouldn't stop, even with control handle all the way down untill it hit the top and reliefed, then went down and started working normal again. I can let it sit running and with handle up about 3/4 of full up position somtimes it will start creeping up and there is nothing you can do about it until it finishes it's cycle of the piston hitting that pin and reliefing it. It doesn't move at all in draft position, that is what I adjusted the other day (wrong). I'm not sure what to think about this mystery. Trash in a valve?

so I removed cover and adjusted rod to limit that," "Rod"? Do you mean the turnbuckle like link that connects the control valve lever to the control valve? If yes, did you adjust to shorten that link?

larry99sd · Jun 5, 2014

(quoted from post at 09:03:43 06/05/14)

(quoted from post at 22:01:13 06/04/14) Ok, back to work on the tractor, I was waiting for a voltage regulator for the alternator, (got that fixed). It seemed like lift was working just fine in the shop, so I got to thinking, I did have a heavy trailer on it the other day when it was acting up. Put trailer on, drove around, moving it up and down, was working fine, then all of a sudden (after it warmed up good I think), It wouldn't respond to the the control up or down, so I left it up, (tractor is sitting still) after about 10-15 seconds it started creeping up and wouldn't stop, even with control handle all the way down untill it hit the top and reliefed, then went down and started working normal again. I can let it sit running and with handle up about 3/4 of full up position somtimes it will start creeping up and there is nothing you can do about it until it finishes it's cycle of the piston hitting that pin and reliefing it. It doesn't move at all in draft position, that is what I adjusted the other day (wrong). I'm not sure what to think about this mystery. Trash in a valve?

Click to expand...

so I removed cover and adjusted rod to limit that," "Rod"? Do you mean the turnbuckle like link that connects the control valve lever to the control valve? If yes, did you adjust to shorten that link?

es, i shortened it, the are calling this the draft control linkage in the manual. I'm assuming that is why the lift won't work now with the draft lever down.

JMOR · Jun 5, 2014

(quoted from post at 20:19:36 06/05/14)

(quoted from post at 09:03:43 06/05/14)

(quoted from post at 22:01:13 06/04/14) Ok, back to work on the tractor, I was waiting for a voltage regulator for the alternator, (got that fixed). It seemed like lift was working just fine in the shop, so I got to thinking, I did have a heavy trailer on it the other day when it was acting up. Put trailer on, drove around, moving it up and down, was working fine, then all of a sudden (after it warmed up good I think), It wouldn't respond to the the control up or down, so I left it up, (tractor is sitting still) after about 10-15 seconds it started creeping up and wouldn't stop, even with control handle all the way down untill it hit the top and reliefed, then went down and started working normal again. I can let it sit running and with handle up about 3/4 of full up position somtimes it will start creeping up and there is nothing you can do about it until it finishes it's cycle of the piston hitting that pin and reliefing it. It doesn't move at all in draft position, that is what I adjusted the other day (wrong). I'm not sure what to think about this mystery. Trash in a valve?

Click to expand...

so I removed cover and adjusted rod to limit that," "Rod"? Do you mean the turnbuckle like link that connects the control valve lever to the control valve? If yes, did you adjust to shorten that link?

Click to expand...

es, i shortened it, the are calling this the draft control linkage in the manual. I'm assuming that is why the lift won't work now with the draft lever down.

robably is the reason. That link is the only connection to the control valve spool & thus, it affects lift in both Draft & Position control.

larry99sd · Jun 9, 2014

I'm glad I didn't use those measurement as they are way off. I noticed later in the procedure it says if the tools aren't available to set the draft at .342" and position at .432". Not sure how I missed that earlier. Just incase anyone has run into not having the tool, these are the correct numbers per manual FO-19.

NAA Lift acting crazy

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