Loader plumbing

[Car Doc]

As a side note.. What is a curl?

Its dump in my terminology.

 

[California]

I am no hydraulics expert but how can a HP line also function as a return? Having the loader valve in series puts the return back into the same HP line yes?

I don't know much about this (as shown above ) but it helps me understand, to realize the pump is positive-displacement and fluid is moving through the system at all times. While it is capable of 2000 psi when choked off, most of the time it passes through the loader and 3-point valves at high volume but no pressure without doing anything, then after the 3-point valve it dumps into the sump. (Side note: at 4+ gpm and a 4 gallon sump, 100% of the fluid passes through the pump each minute).

Simplest case: When you pull the loader valve lever, fluid is diverted to the loader cylinder. Pull the lever the other way and fluid returns to the non-pressurized line, and flows onward to the 3-point. Then through it and to the sump.

Clearly, the more complex install using using the PBY port and with Loader-Out plumbed to a sump return eliminates interaction between lowering the loader and lifting the 3-point.

 

[Car Doc]

IMHO as I said by my logic flawed as it may be :laughing: the return is still going back into a HP line regardless whether it technically "works" by passing fluid up to the point a valve is moved to direct flow to a cyl or back from my perspective time will tell because I am going to go the extra and plumb mine like kenmacs so at this point I cant take a strong stand either way. :thumbsup:

And beside all that what is the difference in having the 3 pt at some certain point in order to operate another attachment on the same circuit that is what the "expert" at Koyker tried to say and he also said my filter must be plugged or my pump is bad.

That may be in certain situations even mine however I am giving credit to my tractor dealer for putting a new one in with the new fluid I know for a fact they did replace. My point there is I may have something on the back and there may not so what I have to always be looking back to see if I am holdin my 3pt right that aint happening? That was my comment to the Koyker guy also.

Another fact is these grays were from what I gather not intended for any other hydraulics to be in use my bigger model has a hose coming out and back in on my 3pt valve block it may well turn out to be the magical power beyond I needed may never know but its there for a rear remote for all I know? Meaning if they needed aux hydraulics in Japan in the paddys they would have put a proper port and return on them which these dont have.

 

[Smoody]

well somebody post a diagram of how its suppose to be hooked up then, if the loader valve doesn't have power beyond, what is the correct way or workaround to have it functioning properly? if the valve does have power beyond but there is no diverter block on our yanmars where does it go at that point?

 

[284 International]

Smoody, I think that if the valve lacks power beyond, you plumb it in series with the three point valve. The contention, as I understand it, is about the instructions to ignore the power beyond port on the valve.

It's my impression that the plumbing diagram shown is for simple installations: The valve flows in series, and no other additions are needed beyond whatever the valve itself operates.

The power beyond would allow the three point lift to function simultaneously with the loader, as I understand it, but would require a separate return line to the reservoir.

I think that if you just have a simple valve with no power beyond, you can plumb it according to Hoye's diagram, but, as others have pointed out, it is wise to make sure that the fittings on the out port of the valve are rated to the same pressures as the other side.

I'm supposed to be getting some parts for a project today, so I'll be making some mistakes on this topic soon that we can learn something from... :laughing:

 

[Smoody]

Smoody, I think that if the valve lacks power beyond, you plumb it in series with the three point valve.

Just to be clear, Hoye's diagram is showing it plumbed in series, correct?

 

[Scotty Dive]

I have no knowledge to add to this discussion, but in my operation manual - it says that some 20 series tractors (and I think FX) had a UFO control that combined electronics and hydraulics to keep a special tiller horizontal.

Do we have any members on the board with these devices who can share how the Gray market UFO is plumbed?

 

[284 International]

Yes, it is in series. As with electrical circuits, if one part of it is blocked or broken, everything "down stream" fails as well. In one side, out the other is another way of putting it.

With power beyond, there is always a high pressure side passing fluid, so pressure is available (power) even if a work circuit is in use.

 

[Smoody]

thanks for explaining it, i never use the loader and the 3point at the same exact time, ofcourse I have the rear implement raised while operating the loader.

 

[California]

Just to be clear, Hoye's diagram is showing it plumbed in series, correct?

Hoye's diagram is (in theory) identical to the divider block instructions in Yanmar's YM240 manual. But from what I am reading here, that is a less-than-ideal compromise to make up for lack of a return-sump fitting on the Yanmar's transmission and/or a lack of a PBY fitting on the loader valve.

YM186 in contrast has both those fittings, so its manual recommends the more elegant configuration. (loader's PBY to 3-point-in; Loader Out to sump.)

Either will work. The second alternative avoids interaction between the loader and 3-point.