Hydraulic question

[CVHoss]

My son recently purchased a Ford 4000 tractor and there seems to be a problem with the hydraulics. I realize this isn't exactly a CUT, but since the members here are the best source of information I've found, thought I'd run it by everyone and see if I could get an answer for him.

As part of the purchase, he had a new Allied loader installed on the tractor. He didn't notice it at first, but there is a definite pulsing of the hydraulic hoses feeding the loader. This doesn't seem to take place while using the loader, only while in a stationary position. The pulsing is hard enough that the hoses actually jump and the "pulse" can be felt throughout the tractor. The pulse occurs every 3-5 seconds. It seems to be related to having the 3ph at it's highest position. If we lower the 3pt even a slight amount, the pulsing is reduced considerably, though not totally eliminated.

Any ideas or remedies?

Thanks,
Hoss

 

[RonL]

Hoss

Sounds like something to do with the bypass. The bypass isn't opening smoothly. Maybe someone familiar with the hydraulics on your tractor can tell you how to check the bypass. Just my guess.

RonL

 

[PeterT]

Have you checked the fluid level sounds like it may be a little low, by lowering the 3point you are putting fluid back into the tank.

Good luck peterT

 

[L3710GV]

Sounds like air in system-

Have you run the loader cylinders to both ends of stroke? or possibly foamed fluid caused by new loader cylinders eating up enough fluid to cause pump to gulp air-low fluid leval-check after foaming has gone away

Or possably the three point feedback linkage is out of adjustment- causing system to bounce on/off of relief pressure

 

[CVHoss]

Ron,
</font><font color="blue" class="small">( Sounds like something to do with the bypass )</font>
That was my first thought. If it is, sounds like he needs to take it back to the dealer he purchased it from.

Peter,
</font><font color="blue" class="small">( Have you checked the fluid level )</font>
Good question. We can't seem to locate a "fill to" plug. There is a plug on the top of the transmission for adding fluid, but we have no idea how full it's supposed to be. The dealer is supposed to be getting him an owner's manual for it, but until then, we're a little lost on this aspect.

L3710GV,
</font><font color="blue" class="small">( Sounds like air in system )</font>
Tried that one too. Ran the loader to full height and cycled the bucket cylinders several times. Didn't seem to help.

</font><font color="blue" class="small">( Or possibly the three point feedback linkage is out of adjustment )</font>
O.K., that one you got me on. Don't even have a clue what the feedback linkage is or where it's located. If we can't get it stopped, guess that's one to ask the dealer.

Thanks everyone, and if anyone has a different idea, I'd be happy to hear it.

Hoss

 

[KiotiJohn]

When I have any kind of hydraulic problem the first thing I do is to make sure the filter is cleaned. Not sure where it is on the 4000, but it's probably a metal screen that can be cleaned and put back. Check at the trasmission. Also, run the hitch up and down a few times and then the loader, cycling through all the moves then put them both down and let the tractor idle for 30 seconds to see if you can burp the air if any. Let us know what you find. John

 

[L3710GV]

3 point feedback linkage on a kubota is the small rod that connects to the output shaft of the lift arms, it tells the 3 point control valve that the lift arms are at there upper limit. If this rod is out of adjustment lift arms can't go any higher to signal control valve (thru small rod) to stop lifting, sending system into relief pressure-- much like holding loader control after it's reached limit of its travel. pressure dumps then builds back up causeing the pulseing- which explains why pulsing goes away when 3 point is lowered

 

[KiotiJohn]

Cool L3710GV, learn something new every day on TBN! John