4430 Primer Pump Leaks

waynetx

New User
I recently purchased a '75 4430 that leaks around the primer pump shaft when priming. From searching, I believe I would have to take it to a diesel engine repair facility to get it rebuilt. Is this correct or can a person do the rebuild themselves?

I have found a pump on ebay that is a different style. Can I replace the pump on my tractor with the ebay type?

Here's the ebay one....

https://www.ebay.com/itm/Fuel-Pump-Hand-Primer-John-Deere-4050-9400-4630-4240-9650-7700-7700-4430-4440/131959376295?epid=1017956307&hash=item1eb96449a7:g:L-cAAOSw2D1ZgSHr

Here's mine....

5772.jpg
 
The one you found will work, it’s the updated one. Shut the fuel off and unscrew it, keep track of the spring and check valve and install the new one.
 
That's the early Bosch primer, the latest replacement # is 2 447 010 033. Just remove the old one as it threads in, replace the copper gasket that comes with the new type primer, making sure the small valve and spring are still in place before threading in the new primer. I keep them on hand as most original primers need replaced as they leak after several hours use..
 
I finally got the updated pump. I haven't gone to the ranch yet but the new one looks to have a lot smaller threads. Does it require an adapter/bushing of some sort?
 

Will a bad primer pump keep the tractor from running? I have a 4430, I can keep it running as long as I pump the primer pump. Once I stop or quit priming it, the tractor will quit running. Your thoughts?
 
(quoted from post at 14:01:06 04/06/19)
Will a bad primer pump keep the tractor from running? I have a 4430, I can keep it running as long as I pump the primer pump. Once I stop or quit priming it, the tractor will quit running. Your thoughts?

The part the hand primer screws into is the fuel pump AKA transfer pump.

If it is not working, the injection pump will starve for fuel.

Something is likely wrong with the check valves (Key #5) or the pumping piston (Key # not shown separately), but next to spring Key # 11.

For that matter, the spring could even be broken.

The transfer pump can be repaired or replaced "in the field" separately of the injection pump itself.

IIRC, both Bosch and Denso injection pumps were used over the production run, and the transfer pumps are similar, but not interchangeable.

QoHzuKd.jpg
 
(quoted from post at 12:54:32 04/06/19)
(quoted from post at 14:01:06 04/06/19)
Will a bad primer pump keep the tractor from running? I have a 4430, I can keep it running as long as I pump the primer pump. Once I stop or quit priming it, the tractor will quit running. Your thoughts?

The part the hand primer screws into is the fuel pump AKA transfer pump.

If it is not working, the injection pump will starve for fuel.

Something is likely wrong with the check valves (Key #5) or the pumping piston (Key # not shown separately), but next to spring Key # 11.

For that matter, the spring could even be broken.

The transfer pump can be repaired or replaced "in the field" separately of the injection pump itself.

IIRC, both Bosch and Denso injection pumps were used over the production run, and the transfer pumps are similar, but not interchangeable.

QoHzuKd.jpg

Thanks, I will give it a try.
 
(quoted from post at 12:01:06 04/06/19)
Will a bad primer pump keep the tractor from running? I have a 4430, I can keep it running as long as I pump the primer pump. Once I stop or quit priming it, the tractor will quit running. Your thoughts?

Malfunction of the pump pressure control valve will do the same.
When priming, you should feel backpressure at the pump after few strokes and an hissing sound should be audible.
Otherwise, check if the return valve is in good shape (return fitting). It is likely that a PO removed/lost the spring.
 
(quoted from post at 00:29:03 04/07/19)
(quoted from post at 12:01:06 04/06/19)
Will a bad primer pump keep the tractor from running? I have a 4430, I can keep it running as long as I pump the primer pump. Once I stop or quit priming it, the tractor will quit running. Your thoughts?

Malfunction of the pump pressure control valve will do the same.
When priming, you should feel backpressure at the pump after few strokes and an hissing sound should be audible.
Otherwise, check if the return valve is in good shape (return fitting). It is likely that a PO removed/lost the spring.

When you pump the primer, diesel rushes out of the top of the primer valve, I broke apart, each section, it appeared all the springs were in good shape. However, the large cap on the front of the pump, I couldn't break loose. I'm hoping, I can break it loose and see what it looks like.
 

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