HYDRAULIC - Yanmar Flow for Power Beyond, Power Steering and 3PT

[Jtullis13]

Scotty that is good news! From what has happening with mine I wasn't for sure what was wrong with yours, but we have 2 different loader valve manufactures too. Anyways good to hear and hope it works well for you. So far mine has been great.

 

[clemsonfor]

Was the whole point to this to slow the rate of decent down or to speed up one process over another? I cant remember now and don't want to have to read pages to figure out.

I think it related to the slow steering or one operation robbing power from the other and the steering being very sensitive to adjustment of flow.

 

[Jtullis13]

Was the whole point to this to slow the rate of decent down or to speed up one process over another? I cant remember now and don't want to have to read pages to figure out. I think it related to the slow steering or one operation robbing power from the other and the steering being very sensitive to adjustment of flow.

Initially Scotty and I were trying to find a solution for the slow loader response after adding PS to our tractors, but then Scotty ran into another problem with his loader dropping to fast before he could experiment. Also with his help we were able to figure out a different hydraulic flow patter that has worked for me so far.

 

[clemsonfor]

gottcha. Thanks

So you didn't have the fast loader drop also?

 

[Jtullis13]

I did have a fast loader drop, but it wasn't because my loader valve was bad, it was due to the flow pattern which I switched and then that problem was resolved. I also was able to obtain better loader response and Near full PS too.

 

[woolyAcres]

The only update I can share is that Brand replaced my loader valve under warranty - Swapped it in, but besides testing for operation, I have not been able to use the loader with any weight to test the drop rate under load Hope to get to that soon, but my schedule has been a bit busy to say the least.

Hi Scotty- Glad to hear you got your loader valve working/replaced. I'm curious. Are you able to lift & curl or lower & dump at the same time? To put it another way, are you able to run the boom and bucket cylinders at the same time? What model valve did you end up with? Thanks.

 

[Scotty Dive]

Hi Gang....An update....much success and a costly mistake....

But first...To answer Wooly's question: Yes I can raise the loader and raise the bucket at the same time. I got the LV22 Valve from Brand that also includes float. I did not get regeneration as I just didn't see the need. There are lots of configurations of the LV22 Valve I don't want to confuse anyone because each mounting location might be different therefore change the part number. I will be happy to provide pictures of my set up if anyone is interested.
On to the work I have done on this...

So, the issue I wanted to fix is the loader not being response at low RPM's and having a either or situation. Either my loader function quickly and strongly and I lost Power steering, or I had great power steering with no loader control. I could find a happy medium but that meant good power steering and loader control only at high rpms. This may not seem like an issue, but when you are going into a pile and reduce your rpms/speed, I would lose loader functioning. If I get the RPMs up so I would have loader functioning, I would come into the pile way to fast. It was a mess and just begging for me to break something.

I have a reputable local hydraulics shop somewhat nearby and I took my drawings down to them. They agreed that taking the out flow of the power steering (instructions say to go to the tank) and combining it with the EX port of the Flow Control Valve would not hurt anything. Instead of a Y like Jtullis did they suggested I use a T.

So that’s what I did and it gave me the following:
1. Loader response was much quicker at lower RPM's - Just like it was before I added Power Steering
2. Power steering response was stronger and easier to steer with.
3. The wheels turned to the left constantly.
4. Loader and power steering worked together and didn't cut each other off
5. 3pt does not work when using the loader - That's normal in my opinion because my 3pt is plumbed using Power Beyond so the loader valve has to be in the open center (not being used) position for oil to flow to the 3pt.

When driving the tractor it would noticeably pull to the left and wasn't difficult to hold it steady, but if you let go of the wheel it would turn to the left pretty quickly. I adjusted the FCR and regardless of the adjustment it made no change. This makes perfect sense because the FCR is just splitting the flow and I am combining it back, so the sum is the same. Honestly, at this point I was pretty happy but I took a trip back to the hydraulics place and they felt I was having back pressure through the system and we agreed adding an inexpensive ($13) 5psi one way check valve on the Out port of the Power steering might fix the problem.

After Installing the check valve, It was better but not perfect. It still pulled slightly to left but I noticed another issue. When I bottomed out the curl cylinder, my tires pulled hard left. I assumed and another trip back to the hydraulic shop, these guys agreed that I was getting back pressure back from the loader valve into the power steering cylinder. So I suggested I install another check valve on the Ex port to the T. The logic here was that now all of the oil would flow to the loader valve and none would go back down to the power steering cylinder. And so...here is where it gets interesting and costly. After I installed the second check valve, there was no change whatsoever. There was still the slight pull on the tires to the left. Which is interesting because now the only pressure its getting is from the pump, but there is no adjustment on the power steering cylinder so it just wants to extend the rod. So, I decided to change the adjustment on the FCR, and WHAMMO! I blew apart my brand new 9cc pump's case. I was spitting nails. As a reminder, The good folks at Hoye had let me purchase a new 9cc pump when this all started. The thought here was that maybe my 7cc stock 30+ year old pump was tired and not pushing enough fluid. Hoye allowed me to buy the pump and return if I didn't make any difference. I decided to keep it anyway, but it didn't make much of a difference. More on that in a minute.
So, I removed the cracked pump and the whole time I was asking why the key didn't shear and save my butt and when I got into the pump I saw that the key had broken but not enough to allow spinning the shaft. Additionally there is a nut that goes over the pump shaft and shaft key and is retained by a smaller nut. The larger nut fits into and drives the pump gear. That nut cracked on mine - I can't figure out the part number yet, but will need to order one. So, I grabbed my original pump, reinstalled the cracked nut and made some gaskets and reinstalled and waited 24 hours to let seal up. I had no choice but to reuse the cracked nut as I needed to get the tractor removed from where it was parked when the pump blew. So this morning, with some hesitation, I started her up....no leaks. OH - VERY IMPORTANT. I removed the check valve from the hose running from the FCR’s EX port to the T at the loader. This way, I have a path in case I ever over pressure the system again by accident.
So, At the moment I have noticed:
1. The 7cc original pump is so much quieter than the 9cc pump. The 9cc pump just squealed and whined. The original can't be heard.
2. I cannot notice any difference between the two pumps - which is odd because I should. I wonder if the whining and squealing were indicators of a bad pump? No way to know now.
3. This is what I have; Loader responsive at all rpms. Power steering that is very easy to turn. A slight pull to the left constantly. IT doesn’t fight me to turn left, but you can feel it. I have a suicide knob on mine so it’s a snap to control the steering. Hydraulics folks told me that I am not wearing out anything or damaging anything by it doing this. So I am pretty happy. I will say I am hesitant to make any more changes because of the cost to me of the pump. I would like to get a new 9cc pump at some point but not sure when and will report out if it changes anything - it should but didn’t so far with me.

Lastly, I have been working with Jtullis on this. I hope he chimes in because I believe he is also going to make these changes and report out with his 2210 and a Koyker loader.

Picture of my set up:

 

[Jtullis13]

Scotty that is a awful, sorry to hear that happened. I have not had the chance yet to switch my hydraulic setup. For those who have followed this thread my set up is pretty close to Scotty's,. I plan on redoing my very soon to see if any changes occur for me. Sorry to hear about your pump again Scotty.

 

[woolyAcres]

Hi Scotty, Sorry to hear about your troubles. Blowing out a pump has to be pretty depressing. Thanks for taking the time to write all this up for the rest of us to learn from.

BTW, my valve has regen, but I can't seem to do two functions at once, which is why I was curious. It's possible it's a different model. They sure do get confusing... Best of luck.

 

[Scotty Dive]

Wooly ....I would call brand...maybe they had a bad batch because you should be able to lift the boom and curl at the same time.


JTullis....no worries....it's just the cost of experimenting. I am very pleased with the results I have now....just don't use the second check valve

 

[Jtullis13]

Scotty I'm glad you got your system fixed. It has been pretty cold here and I haven't attempted to redo my setup yet because of the cold weather. But this spring I may change it. As of now mine has been fine with no issues.

 

[Scotty Dive]

Jtullis - Did you make any modifications to yours?

 

[rScotty]

Initially Scotty and I were trying to find a solution for the slow loader response after adding PS to our tractors,...SNIP

That's always been a problem with the add-on power steering. You want the steering to always work, but to work without stealing every bit of flow from the rest of the systems. In a perfect world, the steering would always have exactly the same amount of flow so that the same steering effort would always give the same amount of wheel turn. A dedicated power steering pump like cars use is maybe the simplest way to do that.
Since tractors already have high pressure hydraulics, the way it is usually done in the tractor world is to feed all the hydraulic output into a part called an adjustable flow splitter - also called a "prioritized diverter valve". From there, one output is a priority leg for the power steering. Excess fluid goes to the loader and to the return circuit. Those valves are never perfect and tend to be RPM sensitive. PS priority is usually set so that steering priority gets full flow just above idle.

The fabulous YM336D used exactly that sort of valve for their power steering and loader combo. Theirs was a pretty sophisticated valve and made the steering almost completely insensitive to RPM.
rScotty

 

[California]

The Yanmar-brand power steering on my YM186D works down to low idle, but it drags down rpms when steering. Also because its gets priority for hydraulic volume, the rpm's need to be raised toward 1000 rpm for the loader or 3-point to come to life.

So slow maneuvering such as attaching an implement or getting forks under a pallet on rough ground, needs mentally balancing a lot of variables. Engine speed sufficient to steer and control loader height and tilt, slow enough ground speed to not arrive before the hydraulic systems have done their work. There doesn't seem to be a 'sweet spot' where all that works harmoniously.

For contrast the YM240's (no power steering) loader and 3-point responses are nearly the same down to low rpm so delicate operation is intuitive without thinking about it.

This US-designed add on steering simply isn't up to the quality of the rest of the tractor in terms of functioning as expected, in my opinion. Its supplier no longer exists so its unsupported. I've put off replacing its piston O-ring (the only oil leak on the tractor) because I don't want to risk damaging the aluminum body casting, I couldn't get it apart with the maximum force I felt was reasonable.

While this makes the tractor far better than no power steering, this power steering add-on is not as good as the rest of the tractor.

 

[rScotty]

The Yanmar-brand power steering on my YM186D works down to low idle, but it drags down rpms when steering. Also because its gets priority for hydraulic volume, the rpm's need to be raised toward 1000 rpm for the loader or 3-point to come to life.

So slow maneuvering such as attaching an implement or getting forks under a pallet on rough ground, needs mentally balancing a lot of variables. Engine speed sufficient to steer and control loader height and tilt, slow enough ground speed to not arrive before the hydraulic systems have done their work. There doesn't seem to be a 'sweet spot' where all that works harmoniously.

For contrast the YM240's (no power steering) loader and 3-point responses are nearly the same down to low rpm so delicate operation is intuitive without thinking about it.

This US-designed add on steering simply isn't up to the quality of the rest of the tractor in terms of functioning as expected, in my opinion. Its supplier no longer exists so its unsupported. I've put off replacing its piston O-ring (the only oil leak on the tractor) because I don't want to risk damaging the aluminum body casting, I couldn't get it apart with the maximum force I felt was reasonable.

While this makes the tractor far better than no power steering, this power steering add-on is not as good as the rest of the tractor.

Yes, I remember that power assist steering kit being an "iffy" proposition even back when it first came out. Forget who made it, but it wasn't Yanmar. It could be adapted to just about any small tractor. BTW, John Deere offered their version of exactly the same ps device when Yanmar began to make the JD compacts, but it worked better. I remember seeing it on their JD650, and thinking at the time that it looked like it would come very close to bolting up to a Yanmar.
Basically it's just a small hydraulic cylinder crudely coupled between the engine frame and the drag arm and otherwise hanging out there in the open along with its hoses and a two way force-sensing valve. If the early ones didn't leak right out of the box, most began to leak shortly thereafter. Endless hassle for the dealers, and the kit had a mind of it's own when it came to how much "help" it was going to provide for the steering effort. Still, it beats the heck out of no power steering. You're lucky to have one...

On most of the imported tractors we always felt that the manual steering gearbox was geared a bit too high - or the torque arm too short. Perhaps loaders weren't popular where the tractors were first developed.
Nice of Yanmar to put real power steering on the YM336/D. For some reason I thought the YM276 also had that power steering. Anyone know?
rScotty

 

[winston1]

I sure don't know for certain but I do have copies of both the repair manual and the parts manual for the 276 and no mention is made in either about power steering. I also have a Yanmar published parts and owner's manual for power steering on the 186 and 186D. I do think I have read of 276 owners having the assist.

 

[California]

... Still, it beats the heck out of no power steering.

Yes, I feel very fortunate to have found this one. Steering - especially when backing - can be palm of the hand on the center of the steering wheel and rotate my wrist. The tractor does the rest. It's lighter than automotive power steering.

And unlike the YM240, catching a wheel on something while backing can't rip the wheel out of my hand.

That kit was great in concept but then poorly designed. If there weren't a shoulder in the way of getting a wrench on the part that blocks access, it would be easy to get in and replace the little steering-piston O-ring, without taking off the hydraulics and taking the whole assembly off the tractor. The leak is real simple, there's a vent hole beyond that little piston (a small piston driven from the steering wheel, not the parallel, larger steering force piston) so the piston isn't bound up. As soon as the piston's o-ring wears and lets fluid past, steering moves the piston which squirts fluid out the vent hole. I put an inner tube 'diaper' on to divert the squirt down away from the sheet metal and some day if someone else posts how they repaired theirs, I'll tackle this one.

A note to anyone who attempts repairs without reading the manual: The manual says don't take apart the balancing valve that maintains equal pressure for left/right turns! I think its a part of the cover where the little piston comes through the cover. The balancing valve requires calibration on factory equipment - which no longer exists.

I have the manual if anyone wants a copy to repair theirs. Thanks Winston for sending a copy of the critical pages, and I have the paper manual that I found on Ebay.

 

[CalG]

I read through this thread with interest in hydraulic systems and assisted steering options.

If I may make some "general comments", please don't consider them either critique, nor suggestion to change what works.

The first thing that caught my attention was the election to NOT return the valve to tank. If I have it correctly, Directional Control Valves can be configured with different seal arrangements that offer differing acceptable values for "case pressure". What works for some may NOT work for others. The fact that the "Power Beyond" function is being accomplished by what should be case drain or "return to tank" ports says a lot about that particular valve seal arrangement. I do not endorse the plumbing this way however. 50-100 psi maybe, but not 2000 psi plus as when using the 3 pt. But, I don't know how those particular DCVs are sealed. This is much like the difference between a two way hydraulic motor and a hydraulic pump. It's all in the seals.

The mention of the difficulty of finding the correct adjustment for the priority flow valve caught my attention as well. It may be because of the reduced differential in system pressures resulting from the high pressure return to tank, but it would seem to me that finer adjustment of the priority valve might be obtained by selecting a compensator spring of a softer spring rate. Springs can be pretty well compared by wire gauge, coil count coil diameter and overall length. A softer spring with sufficient preload could equal just about any setting of the heavier spring and also make screw type length adjustments less sensitive.

It's a pounds per inch relationship. It's possible to modify the original spring, NOT by cutting coils! That only increases spring rate. Reducing the spring wire diameter by grinding the Outer Diameter is a better option. Better would be to see what options might be purchased, then you can always go back to original.

Possibly, an entirely different priority valve might be advised. Of course, not knowing just what type of valve is part of the PS kit, it's hard to make suggestions. But a proportional pressure sensing circuit might allow a balance between steering assist and loader operation under all engine/pump speed and output conditions. It could be that the present valve is sized for much higher flow rates, and so is operating in the margins of it's design specification.

Always remember, pumps do NOT produce pressure, They produce flow. Pressure comes from resistance to flow.

 

[Jtullis13]

Thanks for your input CaIG. Gives us something to think about. And no Scotty I haven't made any changes. My plans was to try the set up that you have. It was super cold this last winter and I put it off and never got back to switching it. It's worked flawless for me. The only problem I have had on a few occasions is hydraulic pump cavitation. First thought it was my filter. So I drained and cleaned the screen, it was pretty dirty. Filled with new fluid and all was good but it has happened twice since then too. So could be something in my plumbing.

 

[Gary Blecke]

Let me apologize for this long thread but hope it will help many of us Yanmar owners out there who have or are planning on installing Power Beyond or Power Steering or a combination of both. However we are looking for feedback from any members who understand this stuff better than we do.

A little Background, I have an YM2020D with a V-Tek loader. My original loader valve did not have power beyond and the loader valve out port fed to the 3pt. This set up is very common on all of our loaders but there have been threads stating it is incorrect. My loader was responsive both upwards and downwards. Also, it raised with strength at low idle. 3 PT worked as it should. No issues at all.
Last fall, I installed the Hoye/Fredrick's Power steering kit and at the same time, I replaced my loader valve on my V-Tek loader. I installed a Brand Loader valve with power beyond and float.
Here is the diagram of how the hydraulics are hooked up with the new power steering and loader valve.



This was done according to the Hoye instructions except for the fact that instead of my loader out port going to 3pt (as it was originally) it now goes to the sump and the loader valve power beyond fed the 3pt. In the Hoye/Fredrick's Power Steering system is a FCR-51. The FCR is a Flow Control block allowing adjustment of flow to the power steering cylinder and the loader valve.
It is clear that since the Power steering is first in the flow that it takes priority and works well, however the adjustment in the FCR is very sensitive and you need to strike a balance between power steering and loader functionality. An adjustment a little one way or the other stops one of the systems from working correctly. I adjusted the FCR to a point where the power steering just barely works as it should. This setting is a 2.5 on a scale of 1-10. I believe this means, 25% of the flow goes to the PS and the 75% remaining goes to the Loader Valve in this set up. For example, adjusting the FCR to a setting of 3 and higher and you lose all loader functionality regardless of rpm and anything below 2.5 you lose all PS and the loader works at all rpms. At the 2.5 setting and at full rpm, I have both power steering and loader valve functionality. However, the loader response is slower and I lost all loader functionality at low idle where I had it before. I then upgraded to a 9cc pump (per the recommendation of Hoye) over the stock 7cc pump. With the new larger cc pump the loader hydraulics were quicker in response but still nonexistent at low idle. Another serious issue experienced was the loader dropped very quickly and violently when a heavy load was in the bucket. It makes finessing a load downward a delicate operation and risks damaging what is in or attached to the bucket and the platform you are dropping it onto. Before Power Steering and the new loader valve this was not an issue.
Now on to my partner in crime; Jtullis13, who has a Yanmar 2210D with a Koyker 120 loader and I have collaborated via PM and on the phone. This all started because he was installing the Hoye PS kit and I offered to lend my experience from installing the PS kit. Based on my shared experiences and what he experienced with his install, he began making a series of configuration changes to the hydraulic routing with varying results. After multiple changes, what he ended up doing is interesting and created a solution that is about 95% perfect. As he made port and flow adjustments certain results were experienced, like the 3pt not working when the loader was being used and the Power steering stopping when raising the boom arms and so on.
What he ended up with is this (his flow diagram is below). Instead of having the flow go to the FCR first per the Hoye Instruction, it flows to the loader Valve IN port. The loader valve power beyond AND the out port connect to a 1/2" Y valve (Purchased off EBay and rated for 10K psi) and the out port of the Y valve feeds the IN Port on the FCR. Let's discuss this logic here. We believe the flow to the loader valve (when the Joy Stick is in neutral (and not being use to tilt or raise/lower) flows through to the Power Beyond. When the Loader valve is being used the excess flow from the cylinders travels out the valve OUT port. By connecting these two independent streams they flow into one stream and provide fluid and pressure to the FCR at almost 100% flow. He set his FCR flow control valve at 7.5. The EX (Excess) port on the Flow Control valve returns to the Tank. The CF port feeds the IN port of the Power Steering. So 75% of flow goes to Power Steering and the 25% excess flow to the tank. Power Steering Out Port feeds the 3 PT. 3PT flows to the Tank.



Now, back to my YM2020D with Power beyond feeding the 3pt, we believe there is no back pressure (like there was when it flowed out through the Loader Valve OUT port to the 3PT) and is why I see the violent dropping of the loader when carry a heavy load. Jtullis13 also experienced this when using Power Beyond supplying the 3PT, but he has eliminated that because his system has some back pressure (we are guessing here) and therefore has much better loader control when lowering heavy loads.
Jtullis13's results are these: He has full use of the loader at all times and rpms. Lowering the boom or bucket with a load is controlled. Power steering works perfectly except he loses partial power steering when lifting the loader (makes sense to me because flow needed to fill cylinders) AND using power Steering. His 3 Pt works and has lifted upwards of 1000 lbs. with it. No whining at the pump. He plans on adding a gauge to his system which I am sure he will share his results if there is anything odd going on. I have one in my system and that's how I found out I was having spikes upwards of 5000 psi when the loader and 3pt were used at the same time. An adjustment of the 3pt fixed that.
So, Jtullis13's results are terrific and I am seriously considering making these changes but a bit hesitant because of my limited experience with hydraulics and not wanting to blow a pump out or worse. We both realize that not having Power Steering first in the hydraulic flow is a No No when it comes to cars, but we are not concerned about losing power steering in the case of a hydraulic power loss. At that moment we have more pressing issues to consider. Plus the steering will still work manually. The question is - is there something glaring that comes to mind that may cause issues with a set up like this?

I have just bought a 1500d and have installed a Hoye ps following your diagram (I hope). 3 pt won’t work if diverter is open any amount. only if closed. ps has stopped severe jolts and improved slightly the ease of steering at any setting of diverter. I can live w/this but should I be satisfied?