Hydraulic pump failure MT300D

[MROlson86]

Looking to rebuild the hydraulic system on my MT300D, is this possible or should I concentrate on a PTO add on pump? I have a two speed PTO so which level do you select?

 

[CausticUrbanCoast]

PTO pump is quite a bit more expensive that getting the replacement hydraulic usually (for the same flow).

Depending on the pump it might also have a rebuild kit available for it.

 

[Roadworthy]

I had a Mitsubishi D2350 and had very good luck finding a hydraulic pump on eBay by typing the model and hydraulic pump. You can probably get more information and parts from Valley Power

 

[MROlson86]

This unit is 35+ years old and the manufacturer of the Hy Pump? I will try Monday at Valley Power and Leonard Schaefer too. A shame not to be able to keep this tractor working.

 

[CausticUrbanCoast]

There are only a few manufacturers, and hydraulic pump housing configurations are pretty standardized.

The hard part is finding the correct cross refernence unless you understand what will fit your format for mounting or coupling. In the WORST case you can make an equivalent flow and power pump fit. It is fairly rare a replacement can not be found. There are still shops that rebuild them as well if you dont want to do it yourself.

 

[Roadworthy]

Okay, I was curious, I admit. Your hydraulic pump is far more common than mine was. You have many choices.

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[PILOON]

There are only a few manufacturers, and hydraulic pump housing configurations are pretty standardized.

The hard part is finding the correct cross refernence unless you understand what will fit your format for mounting or coupling. In the WORST case you can make an equivalent flow and power pump fit. It is fairly rare a replacement can not be found. There are still shops that rebuild them as well if you dont want to do it yourself.

Another option would be to drive a similar CC pump off of the crankshaft and mounting it up front under the radiator. I have a Mitsu and did just that and it is powering my FEL full time leaving the engine pump to power the other functions.
Now over 12 yrs and no issues.

I did this mod as the engine pump was too slow for satisfactory FEL operation.

Mitsu even offered an adaptor for the crankshaft attachment that was meant for an electric clutch but serves well to couple up to a pump.

 

[MROlson86]

I want to thank everyone who has responded. This all started with replacing some leaking/damaged hoses, then cleaning up the controls. Now nothing works, no FEL or 3pt. I am beginning to follow up on the suggestion, thank.

 

[lens12]

Did you dead head the pump?

 

[MROlson86]

No, I didn’t try that. Perhaps you can tell me how? I was first replacing the water pump with one that I got from you. While at it with things disassembled I just kept fixing all of those “little“ things that I’d put off. It happened when I replaced worn and slightly leaking hydraulic hoses and when I ran the engine a few times to check the water pump things were great until I tried to lift my counter weight on the 3 point and lift the FEL to move my MT300D. What a surprise! Any help will be appreciated. It’s too cold to work on it now in my metal building, April sounds better. Thanks for responding.

 

[sd455dan]

Yikes don't do that!
he was asking a rhetorical question.

Deadheading a pump will either fracture the pump housing strip a drive tang/gear or possibly blow a hose. Or if you are really luck the system has a relief built into the system to relieve pressure before a catastrophic failure.

If no funny noises or other odd things happened when you fired up the tractor the first time I would suspect a vacuum leak on the suction side
of the pump.

Until there is fluid in the pump it wont do a whole lot of anything.

A vacuum leak on the suction side will cause the pump to just pump a small amount of air from the leak and it will not be able to pull the oil up into the pump itself. If you can check the draw side for leaks I would start there. You might be able to open the output connection past the pump and then back fill the pump, start it till it spews oil and then reconnect the pump output connection.
Of course if the pump is at ambient pressure (pump submerged) then these suggestions are probably not any help.

 

[lens12]

You don't want to dead head a pump. Dead heading is when the pressure line is blocked. If you disconnected the the loader hoses & they had snap couplers that you did not connect together & ran the tractor the oil from the pump would build up tremendous pressure & damage the pump. There are not rebuild kits for these pumps. I can supply hydraulic pumps for most tractors from OEM & aftermarket sources. I wouldn't mess with a front pump or pto pump. You will still need a pump for the 3 point. I had a tractor with a pto pump. Every time I wanted to use the pto I had to remove the pump.

 

[MROlson86]

What a great thing this forum is! I suspected for a better term the system had lost its “prime.” So I begin again in April when my fingers won’t freeze in the Minnesota/Wisconsin winter. Thanks again for your help and what’s good to know is that future assistance is like my home brew, it keeps and improves.

 

[MROlson86]

Good news, operator error during a repair was the reason for no hydraulic pressure, a quick connect wasn’t fully engaged. It wouldn’t pull apart but wasn’t really connected.
Live and learn.