Backhoe how many hydraulic lines needed to run a backhoe?

[adlertom]

</font><font color="blue" class="small">(
Some tractors have a point where additional hydraulics can be hooked to. It is simply a point at which the series loop can be connected into. In this case, the flow is diverted from the series loop to the new control valve, and then back to into the series loop. So that all the original equipment on the trackor, like the loader and 3PH will still be able to function.)</font>

So, if a new control valve for some new attachment were added to this point, a third line would still be required to get fluid back to the hydraulic tank? It wouldn't be proper to return the hydraulic fluid to the system after it had been used to do work in the new attachment, right?

In other words, if the fluid had been "used" it should go back to the tank. It the new attachment were not in operation, then it would be OK to return the "unused" fluid to the series loop.

Is that correct?

 

[8561]

[
The point I am trying to make is there is a difference between rear remotes that are added to a tractor for use by things such as top and tilt, and what you might need for use with a backhoe.

I think you are correct Henro. The question I have is can I hook my remotes that are in place for my backhoe (which are two lines that simply hook together when not in use on the hoe) to a control valve with power beyond (to say, run a hydraulic top link or a hydraulic snowblower chute) and be able to run lines from that control valve to the backhoe when it's on, and get the fluid to just pass through as you described? /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

 

[Henro]

<font color="blue"> In other words, if the fluid had been "used" it should go back to the tank. It the new attachment were not in operation, then it would be OK to return the "unused" fluid to the series loop.

Is that correct?
</font>

First I am not an expert, but I do have a lot of years of experience in process control in an industrial environment...so take may comments with a grain of salt... /forums/images/graemlins/smile.gif

My guess is that if one would take the "used" hydraulic fluid and put in into the original loop, rather than return it to the tank, it would probably for the most part work anyway, since the down stream control valves would not be shifted...so the return to tank path through them would be low resistance.

From what I can see, many control valves do not have a high pressure rating on the outlet side. So if one were to route the return to tank to the original loop, and a down stream valve were activated, it could cause a pressure rise to occur that could damage the control valve that had its return to tank port hooked back into the original loop...

Myself, I would never hook up a return to tank port to the original series loop. My luck would be my normal luck, and I would do something, somehow, to cause myself problems in the short run. let alone the long run... /forums/images/graemlins/smile.gif

 

[Henro]

<font color="blue"> I think you are correct Henro. The question I have is can I hook my remotes that are in place for my backhoe (which are two lines that simply hook together when not in use on the hoe) to a control valve with power beyond (to say, run a hydraulic top link or a hydraulic snowblower chute) and be able to run lines from that control valve to the backhoe when it's on, and get the fluid to just pass through as you described? </font>

Consider this a WAG...but I am pretty sure I understand you setup.

In my case, to tie into my tractor's hydraulics I need to install a special block that gives me the same thing that you have...a point to take the flow from the pump, and a point to put the flow back into the series loop, where it continues on to wherever it may go.

Right now, there is a block on that point, that simply works like your hose does...connects the outlet point of this area to the inlet point that is also part of this small physical point on the tractor. The flow from the hydraulic pump just passes this point on the tractor...and eventually finds its way back to the tank.

The hose you mention gives you the opportunity to tap into the hydraulic loop. One end of the hose connects to the tubing that comes from the tractor's hydraulic pump. The other end of the hose feeds the hydraulic fluid to whatever is down stream.

One thing that puzzles me is that you don't mention a return to tank hose.

BUT if your setup is such that the backhoe is the last device in the loop, I suppose that would not be a requirement. Since the outlet port would be going back to the tank anyway, and there would be no opportunity for another valve afterwards in the loop to cause a damaging pressure increase.

My GUESS would be that you could hook anything you wanted to the circuit where the backhoe normally is connected, and you would not have to worry about not having a return to tank hose...but if I were you I would get input from someone local who could look at what you have and tell you with more certainty....

 

[JerryG]

In an open center system with a open center valve, you just have to have two hoses attached to the last valve in the series. To do this, the power beyond plug has to removed from the valve and a regular plug installed. This PBY plug is really a sleeve that goes into the valve to determine the fluid flow in the valve.

 

[adlertom]

Is that how tractors with both a front end loader and a backhoe are set up?

In other words, is there a power beyond hose running from the FEL control (which would have supply, tank return, and power beyond hoses) to the BH control, with the BH control being the last attachment in the loop and therefore only needing supply and return hoses?

I suppose another way of doing it would be to have a double 3 way valve, that allowed the operator to select either the front end loader OR the backhoe, but not both simultaneously. With this method, either attachment would be the "last" one (i.e. the only one) in the hydraulic loop.

Perhaps someone who owns a tractor with both can tell us if there is indeed a valve with which they select FEL or BH.

Tom

 

[v8dave]

Not to confuse things. But, it could be that you don't need to tap into the tractor's hydraulics for a backhoe. My Kubota has its own PTO hydraulic pump for the backhoe. The PTO pump has two lines, one from the hydraulic reservoir and one to the control console. The control console has a "used" hydraulic return line to the reservoir.

 

[JerryG]

Yes it is. If the loader is in line first, it has three hoses and the backhoe has two. If the backhoe is first in line, it has three lines and the loader has only two. It is most common to have the loader first, but there are some with the backhoe first.

 

[MadReferee]

</font><font color="blue" class="small">( Is that how tractors with both a front end loader and a backhoe are set up?

In other words, is there a power beyond hose running from the FEL control (which would have supply, tank return, and power beyond hoses) to the BH control, with the BH control being the last attachment in the loop and therefore only needing supply and return hoses?)</font>

Bingo.

That is the typical configuration (NH and Kubota use this) for backhoes that use the tractor hydraulics. In this case, the PB from the loader goes directly to the backhoe inlet and the 3pt and any rear remotes are effectively bypassed and made inoperative. The return from the backhoe goes directly to the tank.

As someone earlier pointed out, in an open center system the last valve does not need to have power beyond. In a standard configuration that wold be the 3pt, in this configuration it is the backhoe.

 

[MadReferee]

Take a look at this thread for a discussion on tractor hydraulics for a New Holland TC. One of the posts in this thread contains the schmatic describing the connections.

TC backhoe connections using tractor hydraulics