Yanmar Hydraulic Pump

Post your questions or problems you are haviing with your Yanmar tractor here.

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KevJG33
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Yanmar Hydraulic Pump

Postby KevJG33 » Sun Aug 23, 2020 1:16 pm

I have an older model Yanmar that was my fathers before he passed. It was purchased without a title and I’m pretty positive the hood was added on from the previous owner. I’m having trouble cross referencing the hydraulic pump for the proper part number I need. The hood says YM 2200 but I have a parts manual my farther received from hoye that’s for a YM2001-2002. Picture won’t upload from my phone but the tag on the pump says:
GEAR PUMP
MOD. GPI-C-7C
MFG. No 3G 210

Pressure 140 Kg/cm2
Discharge 7 cc/rev
Kanzaki koki co. Ltd.

Aaron
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Re: Yanmar Hydraulic Pump

Postby Aaron » Mon Aug 24, 2020 11:27 am

You can usually find the actual model number in the link below
https://www.hoyetractor.com/serial.htm

The GPI-C-7C pump can be found below
https://www.hoyetractor.com/PROD/hp-2010.htm

Are you sure that the existing pump is bad and not a clogged filter or uncoupled hose or something?

winston
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Re: Yanmar Hydraulic Pump

Postby winston » Mon Aug 24, 2020 3:38 pm

Maybe a sheared key? You want to make sure the pump is bad before spending a bunch on a new one. And maybe you are already confident that is the problem.

KevJG33
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Re: Yanmar Hydraulic Pump

Postby KevJG33 » Mon Aug 24, 2020 4:56 pm

Thank you for the quick response and information. I’m fairly certain the pump is the issue, I started having problems while doing dirt work with the bucket. The bucket started getting weak and then bleeding off and lowering while attempting to move dirt to the point it would do it while empty. I changed the oil, cleaned the rear screen and washed out the housing with some diesel. Flushed out the housing with new oil and changed the oil again. I attempted twice since then to use the tractor to which it starts out fine but I believe when oil warms and thins it starts returning to having problems. The last time I attempted use, it was doing it even while cold. So I’m assuming there’s a wash inside the pump that’s progressed. The first time I cleaned it there was very minimal shavings in the housing at which I assume would be almost expected with the way the drive train and everything is within the same area. The hydraulic issue does not just reside with the lift and lower of the bucket but also the bucket curl, and 3 point lift as well. All of which have made me believe the pump was the issue. If you think I would need to trouble shoot something else by all means I’m open to encouragement. I am by no means the mechanic my father was but I believe I’m very mechanical inclined to take on whatever needs to be done. I have opened several of the lines passed the valve body on the bucket and it seems to have sufficient “supply” of oil and no restrictions, only when the resistance factor comes into play with the weight of equipment.

Thank you again for the feedback.

winston
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Re: Yanmar Hydraulic Pump

Postby winston » Mon Aug 24, 2020 5:20 pm

with loader and 3 point affected and clean strainer and fluid it sure sounds like the pump. I guess you could put a pressure gauge somewhere in your system and see what kind of readings you are getting.

However the bleeding off or cylinder leak off would not be the pumps fault. Will your loader stay up when tractor is killed, also will the 3 point stay up with load when tractor is killed?

KevJG33
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Re: Yanmar Hydraulic Pump

Postby KevJG33 » Mon Aug 24, 2020 5:29 pm

Pretty positive one of the things I didn’t try was to lift them and shut off the machine. Mainly due to the fact they were lowering at such a fast rate the last time I attempted to piddle with it while it was running. I guess I could look into it. I just noticed your post about the key and I had not thought of that as a possible outcome. I could pull everything off and check but I had not wanted to fumble with that until I knew it was going to come down to needing to remove the pump to begin with and knowing I had a replacement option due to it being such an old machine. The other gentleman’s information on the serial number shows it is in fact a ym2200 with a 7759 serial number. Although I know there no real way to know actually how old it is.

winston
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Re: Yanmar Hydraulic Pump

Postby winston » Tue Aug 25, 2020 4:03 am

Pretty sure the 2200 was manufactured in the 1970's so you can be assured it is at least 40 years old.

Your statement "Mainly due to the fact they were lowering at such a fast rate the last time I attempted to piddle with it while it was running." would indicate a problem other than the pump. Sure would be interested to here your findings on how fast they drop with tractor shut down.


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