1st post: Hydraulic direction problem

[Shaun M]

I have a new Kubota L3901, 50 hours so far, and I had the dealer put top and tilt on the rear. Sometimes when I press the hydraulic control lever for either cylinder it goes in the opposite direction than it should. The dealers mechanic said this is normal because valves leak inside if theyæ±*e not å��ully engaged? Sometimes if I stop and restart the cylinder it will go the correct direction, other times the cylinder has to fully extend before it goes the correct direction. Along with being annoying, it could easily become a safety issue. Any ideas of whatç—´ going on?

 

[/pine]

Welcome to the forum...
...Your issue query is one I don't recall seeing mentioned before...it is extremely odd IMO...I have had T&T for many years and I have never experienced this issue...changing the hoses/remotes will make the valve work opposite but I have never seen a cylinder move like you've described...

Will be interesting to see how this works out...Good Luck...

Just an off the wall thought that there is something that is not right with the plumbing of the remotes and or the valve...??

 

[LouNY]

Are the valves spring centered or do they have a detented float position.

 

[Shaun M]

Are the valves spring centered or do they have a detented float position.

I don稚 really know. How do I determine that?

 

[/pine]

To answer your question...when you activate one of the levers of the control valve...does it spring back to center and stop the activity...or...are you pushing the lever into a detent that holds it in a forward or backward position?

I have detents w/wo float on my T&T valve but again it has never acted in the way you've described...

 

[Shaun M]

To answer your question...when you activate one of the levers of the control valve...does it spring back to center and stop the activity...or...are you pushing the lever into a detent that holds it in a forward or backward position?

I have detents w/wo float on my T&T valve but again it has never acted in the way you've described...

Mine spring back and stops the cylinders motion.

 

[oldnslo]

Shaun
Does this happen to both functions or just one?
Does this happen in both directions.
Does this happen when there is no load on the 3 point?

 

[Shaun M]

Shaun
Does this happen to both functions or just one?
Does this happen in both directions.
Does this happen when there is no load on the 3 point?

Good questions.
It happens to both functions.
I’m almost positive it happens in both directions.
I don’t think it happens unless I have a load on the 3pt.

 

[/pine]

Shaun
Does this happen to both functions or just one?
Does this happen in both directions.
Does this happen when there is no load on the 3 point?

How are any of these significant??

What would they be indicative of???

 

[oldnslo]

/pine
Reason for the questions was to try and determine if a failing load check could cause this.

If a load is trying to retract the cylinder and you move the lever to try and extend the cylinder slowly the leaking load check would allow the cylinder to retract.

Shaun
Did you ever use either one of these valves for different function or were they installed for the tnt functions.

Getting late and my mind is foggy but trying to picture how the valves would operate if pressure & power beyond lines were switched.

Did Kubota provide a schematic for the additional valves?

 

[Shaun M]

The top cylinder does seem more prone to do this when I’m trying to retract the cylinder slowly when a load is trying to extend the cylinder. I haven’t used the tilt cylinder enough to discover a pattern.

Both cylinders and valves were installed by Kubota new just for the tnt. No schematic.

Thanks for the help.

 

[LouNY]

It is possible under some conditions for the load on a cylinder to over come the valve operation for a very short amount of time and fluid if the valve is being very slowly opened,
and it is possible the return port is opening enough that the higher pressure is allowing more return flow then the operating pressure port is supplying this would allow the cylinder
load to seem to be actuating the cylinder for a second till the desired actuation takes place.
A slightly more robust valve operation when heavily loaded may fix the issue.
Other wise the addition of load checks to the cylinder may be needed.
Many less expensive valves do not have built in load checks.

 

[dannoGT]

I have a new Kubota L3901, 50 hours so far, and I had the dealer put top and tilt on the rear. Sometimes when I press the hydraulic control lever for either cylinder it goes in the opposite direction than it should. The dealers mechanic said this is normal because valves leak inside if theyæ±*e not å��ully engaged? Sometimes if I stop and restart the cylinder it will go the correct direction, other times the cylinder has to fully extend before it goes the correct direction. Along with being annoying, it could easily become a safety issue. Any ideas of whatç—´ going on?

Hi Shaun

Can you take a couple of pictures of valves and hoses? Something is not right and the mechanics explanation doesn't really make sense. Valves should always work the same way every time! Unless mechanic worked on one armed bandits in Vegas?

 

[Shaun M]

LouNY, This seems to be what the mechanic was saying, minus your info about load checks. I’ll try to find out if my valve has them.