Using implement where hydraulic piston has only one hose

audiski86 · Feb 24, 2011

I have a fairly heavy duty single axle military trailer that I am going to put a one ton dump body on. One that I am looking at has a telescopic piston that is only power up - it has only one hydraulic line. My goal is to run the dump of the tractor hydraulics. I have a T4030 with one set of remotes in the rear.

My question is how will this work hooking hooking up only one line to the remotes and leaving the other one of the pair blank? I have only used implements that are 2-way, but I thought some older mower conditioners and things had only one hose for the lift. Is this bad for the hydraulic pump leaving one coupling blank?

Thanks

sweettractors · Feb 24, 2011

audiski86 said:
I have a fairly heavy duty single axle military trailer that I am going to put a one ton dump body on. One that I am looking at has a telescopic piston that is only power up - it has only one hydraulic line. My goal is to run the dump of the tractor hydraulics. I have a T4030 with one set of remotes in the rear.

My question is how will this work hooking hooking up only one line to the remotes and leaving the other one of the pair blank? I have only used implements that are 2-way, but I thought some older mower conditioners and things had only one hose for the lift. Is this bad for the hydraulic pump leaving one coupling blank?

Thanks

Power out 1 line and gravity pushes back the same line going down, No problem. Ken Sweet

audiski86 · Feb 24, 2011

Thanks. So what happens with the one remote that has no line connected to it. Depending on whether I have the lever fwd or back there is fluid that either wants to exit the tractor or enter the tractor. Is there some sort of bypass internally?

J_J · Feb 24, 2011

If your are using A work port for the SA, then either plug B work port, or run a hose from B port to tank/return. By plugging B port, the fluid will be relieved to tank when the lever is activated. .

If there is a QD in the B port, just leave it, would be the same as a plugged B port

sweettractors · Feb 24, 2011

audiski86 said:
Thanks. So what happens with the one remote that has no line connected to it. Depending on whether I have the lever fwd or back there is fluid that either wants to exit the tractor or enter the tractor. Is there some sort of bypass internally?

What would happen, if you pull the lever the wrong way, is the lift pump would squeal. It will do that now if you hit the lever with nothing attached. Ken Sweet

J_J · Feb 24, 2011

It is not the pump that squeals, but the relief valve relieving.

The fluid would exit out of A port at the same time due to the weight of the dumper.

blueriver · Feb 24, 2011

audiski86 said:
I have a fairly heavy duty single axle military trailer that I am going to put a one ton dump body on. One that I am looking at has a telescopic piston that is only power up - it has only one hydraulic line. My goal is to run the dump of the tractor hydraulics. I have a T4030 with one set of remotes in the rear.

My question is how will this work hooking hooking up only one line to the remotes and leaving the other one of the pair blank? I have only used implements that are 2-way, but I thought some older mower conditioners and things had only one hose for the lift. Is this bad for the hydraulic pump leaving one coupling blank?

Thanks

You will not have any problems. My hay cutter has one hose to raise the cutting bar. Plug into your one remote ... do nothing with the other ... as stated if you move the lever the wrong way the relief valve does the job.

audiski86 · Feb 24, 2011

When you say "move the lever the wrong way," don't I have to move the lever the opposite way after I raise the dump? Are you saying that when the dump body is raised to the dump position, it will automatically lower due to the weight when the lever is in the neutral position? I thought I would have to move the lever in the negative or lower direction in order for fluid to be able to escape the piston and return to the tractor. Sorry for the million questions, but I want to make sure before I buy the dump body I am looking at.

AKKAMAAN · Feb 24, 2011

audiski86 said:
When you say "move the lever the wrong way," don't I have to move the lever the opposite way after I raise the dump? Are you saying that when the dump body is raised to the dump position, it will automatically lower due to the weight when the lever is in the neutral position? I thought I would have to move the lever in the negative or lower direction in order for fluid to be able to escape the piston and return to the tractor. Sorry for the million questions, but I want to make sure before I buy the dump body I am looking at.

As you lower the cylinder, oil will drain to tank...at same time the pump flow will be directed to the opposite port, which is plugged. So pump flow will have to bypass over the relief valve....To avoid this you use a special spool in the valve, that allows pump flow go to straight tank at low pressure, when lowering cylinder....
There is no reason to labor pump and engine when gravity does the job....
So get a control valve that is setup for a single action, SA, cylinder.

What to remember here is that return line, and return filter have to be sized for both return flow from cylinder AND pump flow....

Depending on pump flow, you need to pick an appropriate sized control valve...
Example...look at this RD-5000 SERIES SPOOL OPTION......spool options at page V42, "OPTION A"

blueriver · Feb 24, 2011

AKKAMAAN said:
As you lower the cylinder, oil will drain to tank...at same time the pump flow will be directed to the opposite port, which is plugged. So pump flow will have to bypass over the relief valve....To avoid this you use a special spool in the valve, that allows pump flow go to straight tank at low pressure, when lowering cylinder....
There is no reason to labor pump and engine when gravity does the job....
So get a control valve that is setup for a single action, SA, cylinder.

What to remember here is that return line, and return filter have to be sized for both return flow from cylinder AND pump flow....

Depending on pump flow, you need to pick an appropriate sized control valve...
Example...look at this RD-5000 SERIES SPOOL OPTION......spool options at page V42, "OPTION A"

I don't think so ... I may very well be wrong. Hook the single hose to the "up" remote. When you want to dump activate the lever and the cylinder will raise release the lever to the nuetral and the cylinder will "hold" activate again and up she goes ... put the lever in the "down" position and gravity will lower the dump.

Both my hay cutters have one hose cylinders ... this is excatly what I have done for years now ... no special valves. My pump or engine never labor ... Maybe I am missing something ???

rjkobbeman · Feb 24, 2011

Wouldn't this require a float detent to lower the dump? Some action needs to happen to allow the gravity to lower the dump. Pulling the lever to the "plugged B port" doesn't seem like the way to go (would that even work?). Putting the valve in the FD (Float) position would be a graceful way to lower the dump, no?

AKKAMAAN · Feb 24, 2011

blueriver said:
I don't think so ... I may very well be wrong. Hook the single hose to the "up" remote. When you want to dump activate the lever and the cylinder will raise release the lever to the nuetral and the cylinder will "hold" activate again and up she goes ... put the lever in the "down" position and gravity will lower the dump.

Both my hay cutters have one hose cylinders ... this is excatly what I have done for years now ... no special valves. My pump or engine never labor ... Maybe I am missing something ???

Maybe you have a SA spool with out knowing it....LOL

If there is an adjustable work port relief valve in the plugged port, you can disable that pressure setting to almost zero....that will make it....

But when using a spool valve for double acting cylinder, pump flow will be directed to the plugged port, and wont have any ware else to go than through a relief valve , main or work port.....

UNLESS you are FEATHERING the control valve, then pump flow will go through the open center under a lower pressure...If your control valve then is rated for, a way higher flow, than pump flow, you will probably not notice any labor on pump or engine.....

But why buy a more expensive valve (over sized) control valve, instead of a less expensive properly sized valve with a SA spool.......

I do not oppose to "behind the barn engineering"....but I think the purpose with a forum is to put all "cards face up" before you make a decision, and after that you can decide do do what ever you want, and deal with the consequences.....

My 2c....

blueriver · Feb 24, 2011

AKKAMAAN said:
Maybe you have a SA spool with out knowing it....LOL

If I do it came standard on both my tractors ... I have not made any adjustments, added any spools. I just hook up the one hose and go using it.

J_J · Feb 24, 2011

blueriver,

What you said is exactly how it will work. Instead of plugging the B port, you could run a hose off the B port to tank. If the lever is in the down position, the fluid just flows the B port to tank. The A port will drain the fluid from the cyl if the weight is sufficient.

AKKAMAAN · Feb 24, 2011

How SA spool works...

AKKAMAAN · Feb 24, 2011

J_J said:
blueriver,

What you said is exactly how it will work. Instead of plugging the B port, you could run a hose off the B port to tank. If the lever is in the down position, the fluid just flows the B port to tank. The A port will drain the fluid from the cyl if the weight is sufficient.

Oh I got what you meant now...little more back pressure and extra plumbing than using SA spool...... but I agree, that will work...
Thanks J_J....

RickB · Feb 24, 2011

You don't need all that extra stuff.
Your operator's manual gives instructions on turning an external bolt that opens a bypass valve that is internal to the remote valve slice. IIRC it takes a 10MM wrench. Open the bypass and you don't need any extra hose or plumbing, or need to stress your hyd pump by flowing excess flow over relief. RTFM.

A large single-acting cylinder may require more oil to fill than your reservoir can safely supply.

audiski86 · Feb 24, 2011

RickB,

You are correct. In the Operator's Manual, I found a paragraph labeled, "Single/Double Acting Switching." It doesn't go into detail on how it works, but it says in order to switch control valves to: -Single Acting, loosen the screw 1, near the control valve lever pivot, until it stops. That seems like a convenient feature!

As far as the comment on using too much fluid to raise it making the reservoir low, i'm not sure how to tell if that would be the case. This is a 6500 lb tractor that is good size and the dump body is nothing huge, just a 10ft off a 1 ton truck. I think the guy said it was 2 stage telescopic. I suppose I could raise it up and check the fluid level, even if I had to have the level just a bit high when the dump is in the down position.

RickB · Feb 24, 2011

audiski86 said:
RickB,

You are correct. In the Operator's Manual, I found a paragraph labeled, "Single/Double Acting Switching." It doesn't go into detail on how it works, but it says in order to switch control valves to: -Single Acting, loosen the screw 1, near the control valve lever pivot, until it stops. That seems like a convenient feature!

As far as the comment on using too much fluid to raise it making the reservoir low, i'm not sure how to tell if that would be the case. This is a 6500 lb tractor that is good size and the dump body is nothing huge, just a 10ft off a 1 ton truck. I think the guy said it was 2 stage telescopic. I suppose I could raise it up and check the fluid level, even if I had to have the level just a bit high when the dump is in the down position.

Oil volume requirement may not be an issue. But it IS something to be aware of. I am quite familiar with your tractor model and also know that a good sized single acting telescopic cylinder can take a significant amount of oil to fill, possibly leaving an inadequate amount in the tractor. Checking the fluid level in the tractor with the cylinder extended is the best way to tell what is going on. You will have to use an alternative to the dipstick, as more than a couple gallons removed from the tractor will likely drop the oil level below the end of the actual dipstick.