Loader plumbing

California · Sep 30, 2011

Car Doc said:
if I could have an adapter at the sump/suction line at the bottom of the trany case

Is there some way to do this and dump upstream of the filter?

kenmac · Sep 30, 2011

California said:
Is there some way to do this and dump upstream of the filter?

I was going to to tie into the suction. Had I done this It would have been ahead of the suction filter. I didn't want to return ahead of the filter

kenmac · Sep 30, 2011

Smoody said:
I have the 2 handle valve on my allied 195 loader, so I assume by kenmacs info that its plumbed properly, I'f I change to a single control valve guess I will worry with changing it then. This is a very good thread and I don't recall any old threads with this info which is kinda odd with all the information available here.

Can the outlet side of the valve be made to support the higher pressure? Or is that psi rating an internal thing?

If yours has a PBY port. I would use it to supply the 3 pt & outlet for return to sump. Bad thing is, (in some cases) it's not easy to locate a location for return. If I had not had this plate behind the shifter for my return location. I was going to drill & tap the transmission for a return

HoyeTractor · Sep 30, 2011

Using a power beyond valve is probably the best "text book" way to plumb in a loader but it adds complication to an otherwise very simple system. You have to make a fitting to allow you to dump oil back into the fill cap and on a small yanmar it is hard to keep the extra hose out of the way. It usually ends up pretty messy.

I stand behind our instructions- though I may add a link to this topic for more information. The two hose system is simple and it has always worked well. Koyker sent these same instructions along with every loader they shipped out for many years. Then, for a while, there were instructions that said to plug the power beyond port if you didn't want to use it. I'm not sure what they send now.

It is possible that some valves tolerate this setup better than others but I have never seen a setup that didn't work when plumbed this way. I know of lots of customers that have used this setup for many years without problems. I'm, by no means, a hydraulic expert though. I'm just posting what we have had good success with and what the real hydraulic experts have recommended to us as a simple way to plumb in a loader.

deepNdirt · Sep 30, 2011

HoyeTractor said:
Using a power beyond valve is probably the best "text book" way to plumb in a loader but it adds complication to an otherwise very simple system. You have to make a fitting to allow you to dump oil back into the fill cap and on a small yanmar it is hard to keep the extra hose out of the way. It usually ends up pretty messy.

I stand behind our instructions- though I may add a link to this topic for more information. The two hose system is simple and it has always worked well. Koyker sent these same instructions along with every loader they shipped out for many years. Then, for a while, there were instructions that said to plug the power beyond port if you didn't want to use it. I'm not sure what they send now.

It is possible that some valves tolerate this setup better than others but I have never seen a setup that didn't work when plumbed this way. I know of lots of customers that have used this setup for many years without problems. I'm, by no means, a hydraulic expert though. I'm just posting what we have had good success with and what the real hydraulic experts have recommended to us as a simple way to plumb in a loader.

and this is the exact way I was instructed to setup my loader, By the man that provided my new Pump, I was how ever also told from another resource that I could simply remove the PB adapter plug this port, although after having it re-explained and confirmed from JJ, I then decided to Leave the PB adapter and rout the line back to the reservoir/transmission, been working great this way, although I do notice the slow curl at times when working at average engine speed of 1500 rpm's revving it up a bit more does seem to speed up the curl,

Neat 1500 · Oct 1, 2011

i think on the smaller yannies the slow hydraulics is one of its features

mine is plumbed as shown along with many thousands of others and yes mine has that annoying slow curl(dump) on many an occassion which annoys me no end so i have to rev the ring out of it to get satisfactory hydraulic speed.

JCByrd24 · Oct 1, 2011

Smoody said:
Can the outlet side of the valve be made to support the higher pressure? Or is that psi rating an internal thing?

A lot of times yes. Many valves have multiple outlets, and one of them converts optionally to PBYD by threading a fitting/plug into the port. See instructions here:

Note they use both "power beyond" and "high pressure carry over", it is the same thing.

http://www.surpluscenter.com/Instruct/I9-7861.pdf

winston1 · Oct 1, 2011

After reading all these posts I conclude I will leave mine as is with the simple hookup. Don't have a power beyond port so I really couldn't do a whole lot of changing without a new valve. Is there a good answer for why we have that occasional hesitation when using the curl feature? I'm confident at least in my case it is not related to dirty screen or filter. I appreciate all you guys with the sure nuff hydraulic knowledge trying to help us out.

Car Doc · Oct 3, 2011

kenmac said:
I was going to to tie into the suction. Had I done this It would have been ahead of the suction filter. I didn't want to return ahead of the filter

That dawned on me also that would bypass the filter this weekend thinking about how I am going to do mine for sure so the sump return is the best way.

I agree since basically most of the oil could be bypassing the filter thru the loader valve and right back in the inlet of the pump except when the loader valve is being operated.

I am wondering if there is some sort of slight restriction by going thru the 3pt the way these that are plumbed in series meaning it isn't a straight thru arrangement?

If there is that would most certainly could explain why there are some slow loaders out here.

I have a buddy that has a 2420D and his VN loader is plumbed with a bypass going into the sump and not in series with the 3pt. So I know for a fact not every single loader out there is plumbed in series fwtw some body somewhere is looking at this differently besides a few of us. My other friend that just bought a VN 1610D has a VN loader and I am not sure how its plumbed but I will be looking the first chance I get.

J_J · Oct 3, 2011

If you were to put a gage into a tee at the cyl port, you would see if you have any pressure as the lever is moved.

The slow response might be because the land on the spool has not opened the circuit inside the valve to allow fluid to flow to the cyl. This could explain some of it at the start, but the hyd should not hic-up/hesitate in the middle of stroke.

It is also recommended to use the PB port if you have one.

Just about every manufacture says to route the OUT port to tank/reservoir, and there is a good reason for that. Ports on a valve are not made equal, and when they are designing a valve, they specify the tolerances on the ports based on pressure, and that relates to the thickness desired for the ports. In particular, the IN ports and the work ports need to be strong.

There is also something about back pressure and seals in the valve that will affect the normal operation. Some of the back pressure limits are 200 to 500 psi on the OUT ports

If you have a valve with PB as the last valve, you could plug the PB port, and use the OUT port to tank, or plug the out port and use the PB sleeve to pass on the fluid.