FEL hydraulics erratic NH 1720

   / FEL hydraulics erratic NH 1720 #1  

Lumberjack_jeff

New member
Joined
Apr 22, 2004
Messages
13
Location
Montesano, WA
Tractor
New Holland 1720
Hi to all the experts here - I'm throwing myself on your mercy. I've owned my 1998 NH 1720 w/FEL and BH for about 40 running hours (it has 650 hours). I changed the fluid(s) and filters when I bought it. Now (30 running hours afer fluid change) I'm noticing several erratic behaviors;
1) When I place the fel dump lever in float (dump), sometimes the bucket sticks, or operates "jerkily".
2) Placing the bucket on the ground used to consistently lift the front wheels (BH attached). Now, dumping the bucket with it flat on the ground will usually lift the wheels but lowering the bucket will rarely do the job.
3) The biggest problem - when I try to use the loader for excavating (I know - it's not a bulldozer) the loader bucket will flop without resistance about 20 degrees. The problem with this is that setting the bucket for an appropriate angle of attack for optimum digging is not possible because when driving forward, the bucket rotates to a near-vertical position in which digging is impossible. Also, when backblading with the fel, placing the bucket in a slightly down position enables a smoother grading action. The flop in the bucket makes this impossible.

I have removed and replaced both the fel and BH on the tractor. I find it perfectly believable that I've done something wrong, or that I'm missing something obvious.

My ideas;
1) Is it likely that I've gotten some dirt into the fel hydraulics while removing the bh or Fel?
2) Is there a bleeding/air purge routine to follow when changing the oil or removing equipment?

If yes to either of the above, how should I fix it?

thanks in advance
 
   / FEL hydraulics erratic NH 1720 #2  
First check remote handles are fully actuated. When you say dump, I think curl (bucket) and usually float is a lowe((arms), not curl option. Are your hoses plumbed correctly? If they are, sounds like dirt interference with load checks or spools travel. You can't be too clean with hydraulics. If you're brave you can pull spools, load checks and clean. For external equip, a few cycles are all that's needed to purge air.
 
   / FEL hydraulics erratic NH 1720
  • Thread Starter
#3  
<font color="green">If they are, sounds like dirt interference with load checks or spools travel. You can't be too clean with hydraulics. If you're brave you can pull spools, load checks and clean. </font>

I'm not so brave, but profoundly cheap. /forums/images/graemlins/smile.gif

Is there a link you can direct me to that gives me a basic primer for tractor hydraulics, including the best methods to flush? I think your suggestion of dirt in the system is plausible. I try to wipe down the QD when removing equip, but it is very possible I didn't do it well enough.
 
   / FEL hydraulics erratic NH 1720 #4  
Sounds like you may have air in the bucket cylinders. Best way to remove is to operate your bucket to both extremes and holding it there for a few seconds each time. In other words, dump the bucket all the way and hold the lever in that position for a few more seconds. Then the other way. Repeat until air is gone.

One of the most common ways to get air in your hydraulic system is by putting your FEL in the "float" position when it is well off the ground and letting the FEL "float" down. Floating down dumps the oil from the piston end of the lift cylinder with the weight of the FEL (even worse if the bucket has a load in it). The rod end of the lift cylinder then draws oil with the vacuum that is produced. This vacuum can pull air by the seals on the lift cylinders. Once air is in the system it can end up in the bucket cylinders as well.

After you work your bucket cylinders in (max) and out (max), do the same with your lift cylinders to work any air out of them.

OrangeGuy
 
 
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