BX 3 Point Temporarily Not Lifting

[ClendenninTrail]

Three point temporarily quit lifting today. When it was inoperable, the three point would make a hissing sound when I attempted to raise it. I let the tractor set for awhile, thinking that the HST fluid was hot, and afterward, it resumed normal operation. I had pulled a 4ft rotary cutter for about 5 continuous hours on some very steep terrain. The terrain was steep enough to generate a significant pucker factor throughout the whole process. I was in low gear the entire time. The material being cut down was thin grass. There never seemed to be any significant resistance from the rotary cutter. I never smelled anything to indicate the HST fluid was being "cooked."

The engine temperature never moved above middle of the gauge.
I wish we had a tranny temp gauge.

Has anyone else experienced this? Was the HST fluid too hot? Could the HST fluid have been heated enough to change important chemical properties. I just changed the fluid 20 hours ago, refilled with SUDT.

 

[Don87]

Three point temporarily quit lifting today. When it was inoperable, the three point would make a hissing sound when I attempted to raise it. I let the tractor set for awhile, thinking that the HST fluid was hot, and afterward, it resumed normal operation. I had pulled a 4ft rotary cutter for about 5 continuous hours on some very steep terrain. The terrain was steep enough to generate a significant pucker factor throughout the whole process. I was in low gear the entire time. The material being cut down was thin grass. There never seemed to be any significant resistance from the rotary cutter. I never smelled anything to indicate the HST fluid was being "cooked."

The engine temperature never moved above middle of the gauge.
I wish we had a tranny temp gauge.

Has anyone else experienced this? Was the HST fluid too hot? Could the HST fluid have been heated enough to change important chemical properties. I just changed the fluid 20 hours ago, refilled with SUDT.

Is the fluid level good?

Has anyone worked on any of the fittings and used 'thread tape'( tape can come loose and cause flow problems).

Is the lever engaged properly(linkages can come loose).

 

[radioman]

This is a wild guess here but few things to check since it wasn't mentioned in your post:

1. check SUDT level hot and cold. when hot you may see some bubbles. what does it look like when it's cool off overnight? perhaps when you changed the fluid, the fluid had a chance to run through orifices.
2. did you reseat the bypass power beyond hose and make sure the o-ring is not bad letting air in the system? air can do the symptoms you described.
3. when you changed the HST oil, did you also cleaned the strainer from tranny housing?
4. did you have the FEL mounted when you were brush hoggin? If so did you experience loss of FEL controls? IF you did, I would check the spring and shims and make sure there was no foreign objects in the pressure relief port in thee rear of the tractor on left side of the toplink. maybe the spring is weak.

This is just a wild guesses here, but things I would check to have a safe piece of mind.

 

[ClendenninTrail]

Thanks for the great feedback.

SUDT levels checked good this morning, no changes. Ran the tractor for about 1.5 hours this morning set up as TLB. Everything works. No abnormal hydraulic noise.
I didn't check the SUDT for bubbles yesterday, while 3 point not functioning...good idea though.
I did not reseat the power beyond, but the 3 point resumed normal operation after about 20 minute cool down.
I cleaned the strainer when SUDT was changed.
Front end loader was attached. No loss of FEL controls.
No one has worked on any fittings. Tractor has 82 hours on. Bought new in December 2010.

 

[spike23]

Mine makes that sound and won't operate while I'm using the FEL, and vice versa. Maybe something was stuck with the loader?
Chris

 

[TripleR]

Unless it repeats, I wouldn't worry about it as you have checked about all possible causes. May have been something as simple as something blocking the linkage preventing full engagement.