Trouble with loader hydraulic valve

[JIM hudson valley NY]

My old Workbull 202 has been a good tractor but, today, I must have broken something in the hydraulics. I was digging in a pile of wood chips and on one pass the bucket went down but when I went to lift it again nothing happened. The lift handle was just loose and would go down and raise the front wheels off the ground but would no longer lift the blade off the ground so I could drive the tractor. In the photo it is the lever on the left. The spool goes up but will no longer go back down into the valve body. Sounds like metal to metal when I work the lever. I assume I need to take this off and have it rebuilt I really don't know where to begin so I appreciate any suggestions.

The valve body is marked AICO A5A-44R. I know it's obsolete but I hope to find a used one. If the spools or a rebuild kit were available I could have this rebuilt but they don't seem available anywhere. Anyone know of a source?

Thanks, JIM

 

[Jim.ME]

My old Workbull 202 has been a good tractor but, today, I must have broken something in the hydraulics. I was digging in a pile of wood chips and on one pass the bucket went down but when I went to lift it again nothing happened. The lift handle was just loose and would go down and raise the front wheels off the ground but would no longer lift the blade off the ground so I could drive the tractor. In the photo it is the lever on the left. The spool goes up but will no longer go back down into the valve body. Sounds like metal to metal when I work the lever. I assume I need to take this off and have it rebuilt I really don't know where to begin so I appreciate any suggestions.

The valve body is marked AICO A5A-44R. I know it's obsolete but I hope to find a used one. If the spools or a rebuild kit were available I could have this rebuilt but they don't seem available anywhere. Anyone know of a source?
View attachment 65416View attachment 65416
Thanks, JIM

You can pull it apart and if you are lucky, the centering assembly on that spool might have come off the end of the spool.

As for replacing spools. Most valves, especially of that vintage, did not have replaceable spools, they were fitted to the bore in the valve body. So, I would say the thought of replacing a spool is out. It is likely you won't find a kit either. It likely only has a few O-rings, which you can match up at a hydraulic shop or equipment dealer. I would stay away from the hardware store pull drawers.

If the tractor and loader are in good condition and you plan on keeping it long term it might be to consider up grading to a new valve. It will take some fabrication as I believe the valve's return to reservoir port is through the mount to the loader frame.

 

[JIM hudson valley NY]

Thanks, Jim, Yes, it does look like the oil reservoir is in the frame. I can't even figure out where to check the fluid level or add any.? That thing in the upper right corner of the photo is loose like a vent cap. Maybe I must unscrew that? I certainly cannot find a dipstick anywhere.

My local hydraulic repair shop has a place they can send it if I take it off but that looks like quite a project. I assume the fittings are all pipe thread so I can plug and cap all the lines once I get the valve off?

 

[Clarkbug]

Thanks, Jim, Yes, it does look like the oil reservoir is in the frame. I can't even figure out where to check the fluid level or add any.? That thing in the upper right corner of the photo is loose like a vent cap. Maybe I must unscrew that? I certainly cannot find a dipstick anywhere.

My local hydraulic repair shop has a place they can send it if I take it off but that looks like quite a project. I assume the fittings are all pipe thread so I can plug and cap all the lines once I get the valve off?

The vent cap unscrews and there is a dip stick connected to it for checking the oil level.

 

[JIM hudson valley NY]

Wow! I never thought to look! No telling when anyone checked the level so it should be interesting. Thank you!

 

[Brown David]

Thanks, Jim, Yes, it does look like the oil reservoir is in the frame. I can't even figure out where to check the fluid level or add any.? That thing in the upper right corner of the photo is loose like a vent cap. Maybe I must unscrew that? I certainly cannot find a dipstick anywhere.

My local hydraulic repair shop has a place they can send it if I take it off but that looks like quite a project. I assume the fittings are all pipe thread so I can plug and cap all the lines once I get the valve off?

There should/might be a small pipe plug screwed into the fluid reservoir, which is the loader frame, about halfway up the side below the valve body.

When filling the reservoir, remove that plug, when fluid comes out it is full. I made up a short curved pipe to screw in while filling so any overflow can be caught in a bucket,etc. Do this with all cylinders retracted.

Mine has the vented cap to fill it but has no dipstick on the cap.

 

[AviatorforTruth]

My old Workbull 202 has been a good tractor but, today, I must have broken something in the hydraulics. I was digging in a pile of wood chips and on one pass the bucket went down but when I went to lift it again nothing happened. The lift handle was just loose and would go down and raise the front wheels off the ground but would no longer lift the blade off the ground so I could drive the tractor. In the photo it is the lever on the left. The spool goes up but will no longer go back down into the valve body. Sounds like metal to metal when I work the lever. I assume I need to take this off and have it rebuilt I really don't know where to begin so I appreciate any suggestions.

The valve body is marked AICO A5A-44R. I know it's obsolete but I hope to find a used one. If the spools or a rebuild kit were available I could have this rebuilt but they don't seem available anywhere. Anyone know of a source?
View attachment 65416View attachment 65416
Thanks, JIM

Hi Jim, What did you end up doing with the AICO Valve? I also have one of these that has a broken bottom cover.

Tim K

 

[damn1981]

Pull bottom cap on valve centering springs are right there. You can make a gasket for it if need be it's already broke might as well look in it
Really nothing to those valves

 

[JIM hudson valley NY]

Hi Jim, What did you end up doing with the AICO Valve? I also have one of these that has a broken bottom cover.

Tim K

Hi, Tim, I have the old valve off and a new one mocked up with hoses attached except for the return. It's temporarily mounted to a 2x6 to approximate the final mounting position. I have a guy who is making a cover plate and plans to weld some angle iron onto the plate to mount the new valve on. I am not sure how quickly this will all come together but once it does, if all works as well as I hope, I will be glad to share any parts from the old valve. Is your valve mounted on the right hand side of the tractor? They also made a valve to mount on the left that has some casting parts reversed.

 

[AviatorforTruth]

Hi, Tim, I have the old valve off and a new one mocked up with hoses attached except for the return. It's temporarily mounted to a 2x6 to approximate the final mounting position. I have a guy who is making a cover plate and plans to weld some angle iron onto the plate to mount the new valve on. I am not sure how quickly this will all come together but once it does, if all works as well as I hope, I will be glad to share any parts from the old valve. Is your valve mounted on the right hand side of the tractor? They also made a valve to mount on the left that has some casting parts reversed.

Hi Jim , That would be wonderful. Let me know how it goes. Mine is located on the right side. I would think the bottom cover plate would be the same on either installation.

 

[Brown David]

Hi Jim , That would be wonderful. Let me know how it goes. Mine is located on the right side. I would think the bottom cover plate would be the same on either installation.

Mine is on the left side.

I had that plate off to replace the gasket, I'd say the plates are identical.

 

[JIM hudson valley NY]

SUCCESS!

I finally got the old AICO hydraulic control replaced on my MF202. It took a while to find someone with time and expertise to cut and fabricate the new mounting plates.

I purchased a Summit single joystick #P80G-2A1 21 GPM and had them add "float" for $50 extra. Maybe I won't find much use for it but wanted to modernize as much as possible. I only used the new valve a short while but it seems to be just as fast as the original. It does surge a little when going up all the way but that could probably be air in the lines as I mussed around for days trying to make the lines reach without hitting each other. That was the hardest part.

As you will see in the photos, I mounted the new valve just a few inches ack from the original and a little lower. We cut a plate to cover the discharge hole in the loader frame and then welded an ORB weld-on port to it. We then made a template of the mounting holes on the new valve in the mocked-up position where I wanted it. We cut the steel plate and drilled it for the valve and to attach to the new discharge plate. This was all way over my expertise but the guy that did the fabricating made it all look easy. I looked for a quite a while before I found someone willing to fabricate this mount.

The discharge on the new valve and the new discharge port on the frame ended up to only be about 4" apart. I was told that it could be hard-piped but I really wanted a hose so as to absorb any vibration. I ended up with a 45-degree elbow on the valve and a 90-degree elbow on the loader frame so I could route a 36" hose between them without kinking. There are so many hoses there now it isn't really noticeable that there is one more.

David - the bottom cover on the old valve looks fine. I will be glad to send it to you if you PM me your address. It looks like the retaining clip popped off of the bottom of one sleeve assemblies and that's why the valve stopped working. I am sure all these parts are worn out but if anyone has a need just let me know. These old valves are impossible le to find parts for and I looked a while before I committed to replumbing a whole new setup.

I will add a few photos. If anyone wants a photo of something particular just let me know.

 

[MGB-T35]

Jim, I have a MF Model 99 loader with the Aico valve on the left. I scored the bucket lift valve spool while changing seals, Will this spool come out the top of the valve once the bottom cover, snap ring, etc. are removed? If you have any info, photos, or parts that could help me please let me know.

Thank you for the thread.

 

[stevieb49829]

Jim, I have a MF Model 99 loader with the Aico valve on the left. I scored the bucket lift valve spool while changing seals, Will this spool come out the top of the valve once the bottom cover, snap ring, etc. are removed? If you have any info, photos, or parts that could help me please let me know.

Thank you for the thread.

MGB, you are replying to a post from almost a year ago. And the poster was last on this site this last February. You may have better success if you send a message directly to him. Do this by hovering over his "avatar" (the round purple J circle) and follow the prompts for a direct message. And welcome, to Yesterday's Tractors. steve