Hydraulics

[carl_woollaston]

Can anyone help me to understand the hydraulics on my 6945 ?
I want to operate a log splitter and need to provide a fed and return from the Zetor . Ive coupled up hoses to the tractors quick couplers and seleted the midle lever to send oil out through the lower coupler (lever full back), but what do I do to allow the oil back through the upper coupler into the gearbox

 

[ixer0]

Hi, you don't need to do anything, just plug it in. The tractor should have a third coupling on the back - this is a return. You can use this instead, there will be less back pressure.

 

[carl_woollaston]

Humm on my tractor there are only 2 hoses that supply oil from the tractor via the middle lever - pushing forward feeds the top hose pulling back feds the lower hose. Im obviously missing some hydraulic fittings for a return line. Tried to attach a picture but can't work out how to !

 

[ixer0]

Hi, don't worry about the third pipe, you can just plug into the other Q/R coupling. (Someone must have taken the return pipe off at some time). When you pressurize one pipe the other one automatically opens up for your return.

 

[carl_woollaston]

Thats what I thought, but it is still not allowing return oil flow. I've got the lever closest to the seat in the P position ie fully back, then operated the middle lever pushing fully forward, the hose from the QR pulses showing presure inside, no return flow and the engine lugs down. Tried pushing middle lever forward with the same result. Any suggestions ? Do you think the spool in the block isn't fuly selecting so isn't opening the return port ??

My return line must have been removed, so if I get a replacement hose where do I plumb it in ?

 

[bjarne_iversen]

The 9 serie did not have a free return line but you shod have return on the "second" coupling maybe the couplers innturnal valv ist opening.A fre return can be plumd direct to gearoil fillerplug but that means puting a pipe on the cabflore.

 

[carl_woollaston]

Guess that is the hexagon nut next to the gearbox dipstick on the cab floor infont of the levers. Thanks for your help

 

[ixer0]

If the second coupling isn't returning check the condition of the Q/Release couplings, as the other man said. Another thought I had , is the machine piped up correctly?

 

[carl_woollaston]

Now hosed up a direct return to the top of the gearbox, will try to work it tonight. First impression when I start the tractor up and seleted the lever was that the engine still seems to work hard to pump oil round the open centre circuit. Will let you know how it goes tomorrow. Cheers

 

[treaney]

Hi Carl,

Sounds like you are trying to do the impossible for what I've read in this post.

Do you have a spool valve in your hydraulic circuit?

If you send a e-mail to tompreaney@gmail.com, I 'll send you a diagram that will explain how you need to setup your hydraulics.

TomZ