Zetor 3340 3 Point Hitch goes up and wont come down

[rickchambers]

A couple weeks ago I speared a roll of hay, went to field and it would not let down. I have changed cartridge filter and cleaned the magnet and screen filter. I have checked the lever and all the linkage, everything seem ok. After sitting over night it will bread off, it will raise fine but will not go back down. Thank you for any and all help .

 

[Renze]

Had that on a 4712 in the past, when overloading it, i think its the descent valve that gets stuck. I happened with the silage block cutter with a block of maize on it. Solution was to pop the clutch to wheelie it (with the 3pt lever down) as soon as the oil pressure in the 3pt releases, the descent valve releases again.

How heavy are those round bales you have ?

And whats the position of the flow valve lever, in front of the 3pt and external spool controls ? it should be swapped fully right.

 

[rickchambers]

They are not that heavy, we have been feeding the same size rolls for the past three winters. As for the position of the flow valve lever it is the full open position. Dad and I pulled the top off today, didnt have time to do much except look it over. The lever is moving the spool valve in and out, would be nice to have a good manual . We have a parts manual that I found on the internet, work shop manual that we bought (it a joke) and an operator manual and none of them are much help .

 

[Renze]

You can simulate the operation of the 3pt levers by blowing air pressure into it with a rag over the spout. It gives enough pressure to move the lift arms and check what happens when putting it down again. Perhaps one of the rollers doesnt touch the cam anymore: it has two cams that control the depth. they sometimes bend when moving up and down violently, for example with a 3pt dump bucket which lifts the arms up when pushing in reverse when the bucket is in dump position.

 

[rickchambers]

Thanks, we will look at the cams, the tractor is at my dads farm and I only get to make it up there a couple evenings a week. We usually never use the depth control but who knows that may be the problem. I just wanted to post the problem to get all the ideals possible before going back up. The manuals we have are no help and I am not a mechanic by trade but seem to do a lot of mechanic work. Its a lot more fun when you have an ideal of what you are doing.

 

[Renze]

You said depth control, i meant position control: the position control makes the 3pt position relative to the lever position (unlike a front loader, where you just pull a lever, and release it once its at the desired height)

 

[rickchambers]

We keep the lever in the P position.

 

[Renze]

yes thats position control- as opposed to D from depth control, and M for Mixed control..