Power Beyond vs Series for loader valve?

   / Power Beyond vs Series for loader valve? #1  

California

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Jan 22, 2004
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Location
An hour north of San Francisco
Tractor
Yanmar YM240 Yanmar YM186D
I have a new loader control to install on my Yanmar YM240 (YM2000). The old control was in series ahead of the 3-point, as specified in the YM240 Owner's Manual.

This new Prince control says to plumb the 3-point (or any downstream application) from the Power Beyond port on the control, with the Tank (out) fitting on the control separately draining into the transmission sump. It also says maximum back pressure allowed at the control's Tank connection is limited to 500 psi. I have the plug available that would separate the Tank from PB outlets. (Tank then would flow only the fluid returned from the cylinders, not the full continual volume as it does now.)

Do I really need to run separate Tank and PB lines out of this control? Or would plumbing it in series like the old valve work ok? So far as I know there isn't a fitting on the transmission to serve as Tank In. And I really don't want to return it to the dipstick hole as I once saw.

Any advice?
 
   / Power Beyond vs Series for loader valve? #2  
The only reason to plumb in the power beyond is if you need to use the three point hitch simultaneous with loader operation.

Most dealer installed loader valves are plumbed in series.
Remember though, a loader valve for a series installation must have its own relief valve.
And, the loader valve must be able to flow all the GPM's the pump is putting out.

I plumbed a 3 spool valve in series and have never experienced a need to use the three point hitch simultaneously with the valve ahead of it.
I am sure there are applications where simultaneous operation would be more convenient, but I can't think of one.
 
   / Power Beyond vs Series for loader valve?
  • Thread Starter
#3  
Ghenges thanks for the reply. Sounds like I don't have a problem here.
 
   / Power Beyond vs Series for loader valve? #4  
There are multiple mentions of this California here and there and between myself and Kenmac he has his with PB now and mine is still in the works. So I cant comment from personal experience on the PB setup but he can. Talk to one of the used tractor dealers and plumbed in series is the best thing since sliced bread (because its simple) but read between the lines and it maybe just smoke just saying.

Think of the pressure the loader valves are taking when operating the 3 point? Thats one way to look at it besides the fact using 2 controls at the same time may be few and far between. As far as a return to the sump....it could be anywhere may take some creativity is there enough room in the shifter housing or an ispection plate on top of the trany like ours has?

fwtw my loader doesn't work worth a crap right now very unsatisfied with it and I believe the PB will fix it.
 
   / Power Beyond vs Series for loader valve? #5  
All open center hyd valves are plumbed in series.

Prince developed and built the valve , and you would think they would know how it should be used.

There are people that still connect the valve wrong, hoping that nothing will happens, even though the manufacturer says not to exceed a back pressure of say 500 psi.

Well guess what, if the 3pt system can max out the relief at around 2500 psi, do you not think the pressure will backup through the hyd system and perhaps blows the seals or valve itself.

There will be people that will tell you they have been doing it that way all their life and no problems. Even if the valve failed, they would never acknowledge the facts that they did it wrong and just took a chance.

I would recommend to connect the valve correctly and find a way to route all the OUT/return ports to tank, and run the PB with PB sleeve to the next valve.
 
   / Power Beyond vs Series for loader valve?
  • Thread Starter
#6  
JJ you sound like my conscience - I know what you say is right. :thumbsup: But it would be so much simpler to just plumb it like the old one that lasted for decades. Well maybe decades - I've owned this 30 year old tractor for going on 10 years and the curl has always leaked down under load. Maybe back pressure is what did it in. Also this valve specifies 10 micron filtration while the Yanmar just has a fine wire screen, really Old School.

Ok, the real obstacle - Does anyone know if there is some place to plumb a line into the sump?
 
   / Power Beyond vs Series for loader valve?
  • Thread Starter
#7  
... return to the sump....it could be anywhere may take some creativity is there enough room in the shifter housing or an inspection plate on top of the trany like ours has?
No, no inspection plate, or extra space on the shifter. I think creating a return port would mean drilling the transmission casting. Doing that competently is beyond what I can do. I don't see an alternative to returning at the dipstick hole, and I have no idea how to provide a dipstick after that.
 
   / Power Beyond vs Series for loader valve? #8  
Ghenges thanks for the reply. Sounds like I don't have a problem here.

The problem of seeking advice on these boards is that you'll receive so much information it tends to make your head explode.
If your Yanmar manual says to use a series connection, that should be confirmation that the series connection isn't the bugaboo some deem it to be.
Yes, there's a possibility of high back pressure if your three point hitch is carrying a relatively heavy load and you move the three point control while simultaneously moving a loader valve.
My sense is that you won't be moving your three point control lever simultaneous with the loader levers.
Kazillions of FEL's have been plumbed in series by major dealerships like Messicks in PA; have there been valve failures from back pressure, yes, but I think you are intelligent enough to assess the risk and operate your machine accordingly.

What model Prince valve are you using? The LV series is a very popular valve.
 
   / Power Beyond vs Series for loader valve? #9  
Do you have a model or schematic for the prince valve?

Most directional valves will not allow or withstand pressure in the tank port. Yes they may for a period of time depending on construction. My Prince LVT has O-rings installed in grooves in the casting so they will withstand some pressure for awhile. Some models just have a bolt-on cover that seals the ends of the spool. These will not take very much pressure before leaking or breaking.

Major concern would be that back pressuring the tank line will make the relief valve in your prince control valve inoperable. So if you do not have a relief before the Prince valve and the 3PH you could potentially build pressure until the weak link brakes. Could be the valve casting cracking, pump splitting, 3PH housing, etc..
 
   / Power Beyond vs Series for loader valve?
  • Thread Starter
#10  
The problem of seeking advice on these boards is... so much information it tends to make your head explode.
What model Prince valve are you using? The LV series is a very popular valve.

Do you have a model or schematic for the prince valve?

Most directional valves will not allow or withstand pressure in the tank port. Yes they may for a period of time depending on construction. My Prince LVT has O-rings installed in grooves in the casting so they will withstand some pressure for awhile. Some models just have a bolt-on cover that seals the ends of the spool. These will not take very much pressure before leaking or breaking.

Major concern would be that back pressuring the tank line will make the relief valve in your prince control valve inoperable. So if you do not have a relief before the Prince valve and the 3PH you could potentially build pressure until the weak link brakes. Could be the valve casting cracking, pump splitting, 3PH housing, etc..
This new valve is a Prince valve with Float (LVT1GB5AB1) replacing an AICO. The manual says 500 psi limit at the Tank port.

Photos below.

I added into another thread asking about general mounting before starting this PB inquiry, and first posted these photos there. I have worked out the mounting problems; I now plan to mount the new valve hoses-down. The handles will now be correct, and I bought the two In/Out -6 to -8 hose adapters for about $7 total instead of the $50 hose revisions I discussed there. (Plus using these adapters, I could re-install the old valve if my misuse destroys the new valve:mad:)

299586d1359145977-replacing-fel-controls-aftermarket-double-prince-lvt1gb5ab1.jpg


299584d1359143980-replacing-fel-controls-aftermarket-double-p1700386r.jpg
 
 
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