YM226D Project

[California]

I'd love to tell you that is an old style nylon Kimura seal backer for the main engine seal just to see the expression on your face

Oh man you are cruel!

 

[ponytug]

Oh man you are cruel!

Sorry, didn't mean to be. It is more that I live in fear of reassembling something with "extra" parts afterwards, so I can relate.

Still, I am curious what the part really is. What was important enough to index, but not be load bearing, so you can make it out of plastic?

All the best,

Peter

 

[tc197]

Guess what guys...she runs!!!

I can't thank you all enough for helping me get this far. I'm not done yet but today was a huge milestone and relief. I got the side covers and hood back on tonight and look forward to running it around this week and learning the various controls. If everything seems good to go I'll move forward with swapping the loader over next.

 

[tc197]

Was able to do some learning and testing this week. The three point hitch, locking valve and both pto speeds seem to be working. The brakes don’t do much so I need to look into whether or not those are adjustable.

I have had a leak on both sides of the front axle at the knuckles so I ordered the seals and opened one of those up the other night. When I opened the drain plug about a cup of water came out, so I’m glad I checked this. I’ll drain everything, put both new seals in, refill it and get some run time on it before I drain it again to flush any remaining water out.

I’m investigating a small hydraulic fluid leak on the rear of the tractor. It’s like a drop a day so I spent some time cleaning everything really good to hopefully identify where its coming from. I want to square away as much as possible before attaching the loader assemblies. I’m also trying to determine the correct way to plumb the loader in. I could just copy how it’s setup on the old tractor but I’d like to confirm it’s right.

 

[winston1]

I can only guess if the loader was working correctly on you old tractor then it was likely plumbed correctly. However, loaders can be plumbed with or without power beyond. If your old loader had 7 lines coming off the control valve then it was plumbed with power beyond. If six lines then plumbed without power beyond. Are you using the same control valve, hoses, etc. on your new installation?

 

[tc197]

I can only guess if the loader was working correctly on you old tractor then it was likely plumbed correctly. However, loaders can be plumbed with or without power beyond. If your old loader had 7 lines coming off the control valve then it was plumbed with power beyond. If six lines then plumbed without power beyond. Are you using the same control valve, hoses, etc. on your new installation?

I never got to really test the loader on the old tractor. It lifted and curled properly but it was a one second test not under any load.

I have seven lines connected at the controller. The hoses will all be replaced as they are falling apart, but I planned on using everything else. When sitting on the tractor there is a junction box mounted to the right of the three point locking valve and there is a tee coming out the left side of the transmission near the fill cap. The tee splits off to the power steering which I also planned to swap to the new tractor.

 

[winston1]

Based on your description I believe your old tractor was plumbed correctly with power beyond.

 

[tc197]

Thanks Winston!

Got the knuckle seals replaced this afternoon and new gear oil put in. So far so good!

 

[tc197]

Hoping I solved the hydraulic drip for now - found a small 1/8” spot between the transmission housing and the rear of the tractor where a tiny bit of fluid appears to be seeping through (drop or 2 a day). Instead of splitting the entire tractor I used some gasket sealer and so far it looks to be holding.

Got the loader frame off the old tractor and cleaned up today. Hoping to have new hoses made up this week and I’ll get the frame installed and plumbed, as well as the power steering. I’ll also change out the hydraulic fluid, filter and clean the screen so everything's fresh.

 

[tc197]

Turns out the hydraulic fluid drip was coming from one of the bolts. I believe the gasket around the bolt hole has a small leak which allowed hydraulic fluid to reach the bolt. The fluid then traveled up the threads and out between the bolt head and lock washer. I removed the bolt and added a bit of gasket sealer on the threads and so far so good.

I got the loader frame installed and the power steering bolted in place. Just waiting on a fitting for the hydraulic lines so that I can plumb everything in and change the fluid in one shot.

 

[tc197]

Late on an update. Got the fluid changed, cleaned the strainer which was totally gunked up, hooked up all the hydraulic lines, and finally was able to test it out today. The only problem is the hydraulics aren’t working. Power steering isn’t doing anything and the loader isn’t doing anything. 3 pt has worked all along and continues to work fine. Im pretty sure I have everything plumbed in correctly as I copied it from the previous tractor and I know the hydraulics worked on it.

My initial thought was air because the loader was pretty empty from sitting and leaking, but everything ive found online says they self bleed after cycling the controls a few times.

It’s not weak or slow, it’s non existent. Any pointers on what to look at would be much appreciated!

 

[winston1]

Any chance of pictures of you plumbing?

 

[tc197]

Sure thing, I’ll get a video up shortly.

In my searches tonight I realized that deadheadding the pump is a thing. Apparently it’s a no-no to run the tractor with the loader not connected unless the quick connects are plugged into themselves? It makes sense in theory, but doesn’t based on the way my hydraulics are set up. I’d need separate hoses to connect between quick connects which just seems foolish. Might as well not even have quick connects. Anyways- since I definitely ran the tractor with the loader disconnected it seems damage to the shear key/pump may be likely. Would it make sense that the 3 pt hydraulics still work if this is the case though?

 

[rScotty]

Disconnecting doesn't deadhead the hydraulics unless it has been modified by someone. The return flow simply goes down the return line from the loader valve to the sump. No different than if you had the loader hooked up and weren't moving the levers.

Air is never a problem in an open hydraulic system. They will work with air in them and they self-purge. That's a lot of the reason why the transmission/hydraulic sump has a vent.

Did you take the cleanable hydraulic filter out of the side of the transmission and clean? What did it look like?
Made sure that the screw on hydraulic filter is a standard suction type & not some super low flow type.
rScotty

 

[tc197]

Here's a video of the plumbing on the tractor. Apologies if my terminology is incorrect.

Thanks for clearing that up rScotty. Yes I removed the cleanable hydraulic filter and cleaned it. First I removed the upper drain plug and drained the fluid. Then I removed the cleanable filter through the triangle shaped side port and it was covered in gunk. At this point I realized there was a second drain plug right beneath the cleanable filter so I removed that and drained the rest of the fluid. I then reinstalled both drain plugs and the cleaned filter. Yes, I also made sure to use the correct hydraulic filter (purchased from Hoye).

 

[rScotty]

Nice video. Well explained, too. The tractor is a nice one. Nice size and even has the special turf tires. Yes, I think you have one worth the effort - even if it is more effort yet.

I also think you have all the lines correctly identified. The problem probably is - just as you suspected - in that last line that is going from the loader valve (directional control valve assembly to be formal) down to next to the three point hitch drop speed control knob.

I believe that line is actually hooked to the "power beyond" port on the loader valve assembly. BTW, you can check that. It should be marked on the casting as "PB". That would be the proper way to hook up the hydraulics if the only hydraulics are the loader and 3pt.

But you also have a proportional diverter valve and power steering. As it is, it looks to me like you are feeding pressure to the hydraulics from two sources. One source of high pressure is fed directly from the pump to the proportional valve, and the other source of high pressure is coming from the the PB port on the loader valve.

I have no idea what is happening inside. Probably - hopefully - not much except for fluid confusion.

I'd say first step is to take off that hose from the PB port to the 3pt. knob. But there is a problem with just doing that & I'm not sure how to proceed. Let's talk on it for a bit...

You should read this and then read up on PB ports. They are a special port that has a choice of two internal sleeves. One sleeve is used if you are not going to use to use the PB port.
That NON-PB sleeve changes the control valve's internal flow to what it would be if there was no PB port at all. In that case, all fluid not being sent to the loader cylinders will be diverted to the return port and so back to the sump.
To make the PB port functional requires a different internal sleeve. When the sleeve makes the PB port functional, all flow not being sent to the loader cylinders goes out the PB port still under full pressure, and thence it is is intended to go to the next set of control valves. That is OK, because each set of control valves in the serial daisy string of PB-driven control valves also has a return port, and the final set of control valves can then use the final return port in the string to send the unused high pressure flow to the sump.

And there is our problem..... That PB port is probably under high pressure. So we cannot just remove that offending hose and block off the port or hose. First weneed to have the sleeve that depressurizes the PB port and THEN we can just plug that port and everything should work right.

But the problem is that those sleeves are specific to each model of loader valve. They are not universal. When you buy a loader valve with a PB port it comes with both sleeves.

If that is a stock loader valve, Hoye might have such a sleeve....but even he with his vast Yanmar knowledge might not recognize which particular sleeve he has in his hand.

Hmmm......It occurs to me that there at least one other possible way to trick that PB port. I'll give you a chance to work it out first. Let me know...
rScotty

 

[tc197]

Thank you rScotty! I’ll do some digging and report back.

 

[winston1]

If you have changed nothing and installed it on your new tractor the same as old then I suspect this 1/4"plug is your problem.
They make them in steel also but whatever material this is what you need. https://www.amazon.com/Brass-Fittin...aWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl&th=1

 

[rScotty]

If you have changed nothing and installed it on your new tractor the same as old then I suspect this 1/4"plug is your problem.
They make them in steel also but whatever material this is what you need. https://www.amazon.com/Brass-Fitting-Countersunk-Thread-Internal/dp/B081YDQ66X/ref=sr_1_1_sspa?keywords=1/4"+headless+pipe+plug&qid=1636889665&sr=8-1-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFFVU1SSjlCV0lBNjQmZW5jcnlwdGVkSWQ9QTA1ODc4NTFSSTBERlZWOFUyQVomZW5jcnlwdGVkQWRJZD1BMTAzNDA1NDFFQUhIMEdCNFJOQUcmd2lkZ2V0TmFtZT1zcF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl&th=1

Excellent! Winston, thanks for posting that illustration.
I just love those old artistic working view drawings. They explain so much.

That certainly is a good page. Is it from the OEM Yanmar workshop manual with the red plastic covers??

That whole picture is worth studying until understood. I agree that the owner should take a look to see whether that port-blocking screw is in there or not. It could be part of the problem.... and of a possible solution. Note that in the text that headless pressure blocking screw is improperly called out as a NPTF. But in the drawing and as you show it on Amazon the headless screw is actually a NPTM.

A couple of notes:
1. on the illustration, note that the directional valve assembly for the loader is only shown on the upper right in a schematic view. All other views are of the Hydraulic Cylinder Head.

2. The Power Beyond (PB or PBY) port D is shown as being active in that schematic of the loader valve. So in the schematic view there is pressure on the hydraulic cylinder head port A.

3. By the way, that schematic drawing of the directional control valve is an "old school" type of schematic drawing in which some internal return passages are not shown on the control valve schematic. In old school schematics some internal return passages of control valves were considered to be "obvious....."
So don't panic when you mentally move the control levers and find that where ou expect a return passage to show, the flow appears to just end instead of connecting to the return line.

So with the aid of this drawing, the OP may be able to change his hydraulics around so that he can use the PB and not have two competing sources of pressure. Will have to think on that.

Also, I was thinking back to yesterday's video where the OP shows a "T" in the return line. As a general rule, one never wants to "T" into a return line because it causes back pressure on both returns. I don't think that is his problem right now, but it is better to combine both returns into a "Y".

rScotty

 

[winston1]

It is from a copy of the original manual. I had this same arrangement on my old 2002D.