Bucket won't rotate

[ghelsel]

I have a ZEN-NOH ZL 1802FD. The yoke that engages the piston to transfer hydraulic power to the bucket broke. It was replaced and the bucket will travel up and down but will not rotate. I am sure there is one little thing I am over looking. Has anyone encountered this? Please help!!

Thanks,
Greg

 

[Soundguy]

are you saying the valve spool broke and was replaced?

more words=better answer

soundguy

 

[KWentling]

I think he is saying part of the joystick linkage was broken and replaced, and now it doesn't work. I would guess it wasn't installed correctly. Pictures might be helpful.

Kim

 

[grsthegreat]

this may be a dumb response, but alot of tractors have a little lever that can be set to prevent the tilt/rollback (dump) function . some even have a lever to stop up/down movement. can you check down around the area where your control arm comes thru the body of the tractor and see if there is a control of some kind. Im not familiar with this brand tractor.

 

[ghelsel]

I apologize for the lack of info. I am not familiar with this type of tractor either. The hydraulic housing under the seat has a big piston that isolates the hyd pressure to either the bucket or the PTO. You can only use one system at a time. The (internal)yoke that pushes the rod to move the piston forward to isolate the hyd pressure to the bucket is what broke. After we put it back together the bucket will raise and lower but it will not rotate. When we try to rotate it acts like it's in a bind and kinda twists a little like one of the pistons is working but not both. I was hoping there was a simple fix but the more I read and think about it, maybe not. I am unable to get pics at this time but I will try to get some asap.

Thanks again for any help.

Greg

 

[KWentling]

The "housing under the seat" would be the rockshaft housing and the "big piston" inside would be for raising the 3 point hitch on the tractors I'm familiar with. Pictures of this arrangement might help. How did the yoke get broken?

Kim

 

[ghelsel]

The factory yoke is a junk piece of cast. From what I understand this is a common problem. We had one made from 1018 steel so we shouldn't have to deal with it again. The factory ones just shatter after time.

 

[ghelsel]

You are correct on the 3 point hitch being raised by this housing. In addition, once the hitch is raised, the hyd pressure transfers to front and you can use the bucket. I will get pics asap.

 

[kencunningham]

If the bucket appears to be twisting while using the curl function i would think a quick connect has not seated.

 

[ghelsel]

Thanks Ken. I thought the same thing. We never removed the quick connects but I did double check them anyway. I appreciate everyones input!!

Greg

 

[KWentling]

I would take each quick connect apart and recouple them just to be sure. They can look OK but not be fully seated. I'm betting one isn't. Does the engine pull down any when trying to curl the bucket? More than when lifting the loader? If you could rig a pressure gauge on a coupler so you can test at each quick couple, that would tell you if you are getting pressure to those circuits. I've never heard of an arrangement where the 3 point had to be up before you could use the loader.

Kim

 

[ghelsel]

Thanks for the advice Kim. I will disconnect/reconnect all the quick connects to be sure. It is my buddy's tractor and I have never heard of the split in hyd pressure until he showed me the set-up and it is different from what I have seen but it makes sense. He cannot use the bucket while the PTO is in operation. ie.... down position. Once the hitch comes up the motor bogs a little(which is normal according to the user) and the bucket is operational. It doesn't bog more in up or down movement, only when I try to rotate. FYI there is an arm on the right of the assembly(as you sit) that pulls the 3-point hitch up and transfers hyd power to the front(bucket). If the hitch is down, all hyd pressure is dedicated to the PTO and bucket is no-go. This is normal as far as I know.

Greg

 

[J_J]

Install a gage in the system and check pressure. One cyl may be bad or does the bucket only have one cyl

 

[Soundguy]

pto in operation or 3pt hitch?

is this system run off an internal pump that diverts pressure to the loader hyds when the 3pt is blocked?

if so.. the valve needs to be open center.. almost sounds liek a closed center valve if the tractor bogs when the 3pt is diverting oil to hyds and is dead headed thus opening relief..

soundguy

 

[ghelsel]

pto in operation or 3pt hitch?

is this system run off an internal pump that diverts pressure to the loader hyds when the 3pt is blocked?

if so.. the valve needs to be open center.. almost sounds liek a closed center valve if the tractor bogs when the 3pt is diverting oil to hyds and is dead headed thus opening relief..

soundguy

Yes it diverts the pressure. It sounds like you are on to something but I don't understand the "valve needs to be open center" comment. Please be patient, I am hydraulic stupid.

Greg

 

[Soundguy]

open center valves pass hyds straight thru to sump ( or some other valve down stream in the case of Power beyond valves ), any time a function on the valve is not being used.

for a setup that uses a 3pt hitch pump that makes it divert pressure to an external port to then be used with a valve and external cyl, then that valve must be open center style and dump back to the sump.. otherwise if it is a closed center valve it will make the system 'run in relief', and the only time it won't be in relief, when the 3pt is diverting, is when the aux valve is sending oil to say.. another cyl.. etc.

the 3pt diverting oil out to an open center valve which then sends it to sump should NOT load the engine.. in fact.. it should not be noticed at all.. the fact that it is being noticed means there is a restriction on that diverted oil that the engine is seeing.. thus my idea of you perhaps having a closed center valve...

soundguy

 

[KWentling]

Was anything else replaced or altered other than the yoke? And it all worked OK before the yoke broke?

Kim

 

[J_J]

If the loader arms raise and lower, then that part of the valve is good. Install a gage in the base end of the curl cyl port or rod end port, and activate the valve, then tell us what happens .

How about some pictures?

 

[ghelsel]

I'm trying to get back there to take some pics. The tractors is at my buddies house. I really appreciate everyones input and will try the suggestions and let you know. Thanks again.

Greg