Questions: Yanmar 3rd Function Kit for SA425 (TVK-YL210P) Installation & Yanmar TF500A Hydraulic Fluid

[aba4430]

Folks, I am in the process of installing the 3rd function kit on my SA425 and have a couple of questions:

1. The dealer indicates that their installer does not even use the Lock Regen Plate (P/N. 1TN328-43450) included in the TVK-YL210P 3rd function kit. I actually saw one SA425 on their lot without the plate installed. In any case, prior to buttoning up the tractor I wanted to ask here to see whether folks have installed this part or left it out. I have it currently installed between the lock nut and plunger; see attached image. The instructions are not clear. Note, it can also be installed between the long barrell nut and plunger. Please see a picture of my present installation with crude handwritten labels for the parts.
2. Several images included in the Yanmar 3rd function installation kit appear to be incorrect. I called Yanmar yesterday and spoke to a technical rep. He advised not to use the images but follow the written instructions. Yanmar is supposedly updating the installation instructions. Anyway, would love to hear about installation experiences from other owners who have installed the 3rd function kit on their SA series tractors.
3. I have searched the web and most findings indicate that the Hygard J20C fluid meets Yanmar TF500A requirements. Now JD also has a J20D or low viscosity Hygard fluid. I know Yanmar changed from TF500 to TF500A several years ago. Is there any information out there that suggests that the TF500A is a low viscosity formulation similar to the JD20D fluid? Note I used Shell Rotella HD tractor hydraulic fluid for my 50 hour service but this fluid meets J20C and not J20D. If not the correct fluid, I will switch over to the Yanmar TF500A or Hygard J20D fluid. Note, the Rotella HD fluid has been used for about 6 to 7 hours since the change and the tractor performance has been fine.

TIA.

 

[aba4430]

Follow-up:

1. I confirmed with Yanmar tech support that the Lock Regen Plate (P/N. 1TN328-43450) was installed correctly.
2. Completed the installation of the 3rd function kit but still have to organize/tie up the hoses and wiring. I attached my loader to generally test out the loader functions. Found a leak on one of the 3rd function hose fittings on the loader bulkhead. My fault for not tightening up the two bulk head fittings - fixed this. Then I tested the loader out and I have the up and down and curl functions but no dump function. I followed the installation instructions and neglected the images as recommended by Yanmar tech support yesterday. A hose connection or two may be switched I think. Will troubleshoot tomorrow.
3. The hydraulic fluid question is not urgent. The Rotella HD is working fine. I will procure some TF500A down the road and swap the fluid out.

 

[aba4430]

Another follow-up:

1. Spoke to Yanmar tech support this morning and the rep recommended I remove the lock regen plate altogether and test the dump function out.
2. This afternoon I went to pick up some attachments for the Yanmar and looked over a new SA425 with third function kit installed. Took careful notes and pictures of the hose connections on the solenoid valve associated with the kit. All connections matched the images in the installation instructions and not the written instructions. Note Yanmar tech support had advised to ignore the images and just follow the written instructions. In any case after returning with my implements I adjusted the connections on the valve. Now I have the dump function back, albeit very slow. Tomorrow I will remove the lock regen plate and hopefully that will take care of the slow dump speed. Will update.

 

[freightboy]

Another follow-up:

1. Spoke to Yanmar tech support this morning and the rep recommended I remove the lock regen plate altogether and test the dump function out.
2. This afternoon I went to pick up some attachments for the Yanmar and looked over a new SA425 with third function kit installed. Took careful notes and pictures of the hose connections on the solenoid valve associated with the kit. All connections matched the images in the installation instructions and not the written instructions. Note Yanmar tech support had advised to ignore the images and just follow the written instructions. In any case after returning with my implements I adjusted the connections on the valve. Now I have the dump function back, albeit very slow. Tomorrow I will remove the lock regen plate and hopefully that will take care of the slow dump speed. Will update.

What taking the regen lock out will do is allow the bucket to enter a "fast-dump" cycle. This is accomplished by equalizing the pressure on both sides of the cylinder. With the bucket, that will not be an issue. With a grapple or other third-function controlled item the weight of whatever is in or on the implement will potentially open. An example is a grapple holding a log with the opening pointed downward (top jaw is the one that uses the hydraulics). If you are holding a log that weighs 800 lbs, it will open the grapple because the pressure is equalized. This is dangerous and the regen lock should be used.

 

[aba4430]

Thanks for your reply. I have not removed the regen lock plate as yet. However the bucket dump movement is incrementally slow since I fixed the hose connections and this rate is not practical. I will remove the plate and see if the loader dumps at a typical rate. At least then I will know that the regen lock plate is the outlier.

Will not do anything that is potentially unsafe. Not sure why the dealers are not using the regen lock plate when they are installing the kit on brand new SA series tractors. I wonder if reducing the thickness of the regen plate will allow a more practical dump speed while maintaining its intended function on the tractor.

Separately, I am disappointed with Yanmar Tech Support. They have known that there is an issue with the 3rd function installation instructions for a couple of years now, but have not updated the instructions. My 3rd function kit was assembled at Yanmar in August 2024 and included instructions (poorly documented and with errors) from 2021. Moreover, initially I was advised to disregard the images and follow just the written instructions by Tech Support and then yesterday, as noted previously, to remove the regen plate.

Thank you for the information anyway. Will update.

 

[aba4430]

Update: I played around with the regen plate installation yesterday. Loosened the jam nut and found that the SCV lever bolt (barrel nut in my image in original post) before the end rod (plunger in my image) could be moved in or out with rotation. I remembered taking up slack during original installation by rotating the bolt counter-clockwise (looking at it from the front of the tractor) after the plate installation. This may have resulted in limited lever movement to the right preventing the dump function at normal rate. Yesterday, I rotated the bolt clockwise until I had enough space for the plate and hand-tightened the jam nut, and tested the loader function out. Worked like a charm with typical movements. Thereafter I secured the jam nut tight.

In summary, the regen lock plate is installed and the loader behaves typically. Other than this as stated previously, the images for hose connections in the 3rd function installation instructions are correct and the written instructions should be disregarded. I will test the 3rd function out on a grapple that I recently purchased and if there are issues with operations, will update this thread. Once everything works I will update Yanmar and request that they update the instructions.

 

[aba4430]

Tested the grapple out and it works perfectly. Button pushed and lever to the right and it opens. Button pushed and lever to the left the grapple closes.

 

[Jaybr]

I know this is a few months old, but just found the thread in a search. I have a new YT359c with third function installed by the dealer and the dump function on the loader is very slow. After reading this, I assume it just needs adjustment.

Is the picture you posted underneath the joystick or somewhere else on the tractor?

 

[Jaybr]

I found the install instructions for the YT3 kit and see the adjustment procedure for the cable, looks simple enough.

 

[bmaverick]

If you cannot find TF500A anywhere, then opt for JDM J20C aka Hy-Gard.

Other options are for fluids to MEET the JDM J20C spec, not marketing hype saying recommended.
Store brands do use the licensed Ashland-Valvoline JDM J20C fluid too.