Deere 310D. Fuel dribbling from transfer pump overflow orifice after startup

[Sampsonn_]

After sitting for a few days our 310D would start, begin surging, then die. Diagnosed this as being loss of prime. Replaced the fuel transfer pump and this corrected it - starts great and runs fine. But now we're seeing that during startup and for a short period afterwards, fuel is dribbling out of the overflow orifice on the bottom side of the new transfer pump.

I guess I should admit that I'm not actually certain what this orifice is for, but I can't see any other reason for there to be a small uncapped hole on the fuel pump, so an overflow is my assumption. The old transfer pump had the same orifice but I don't recall ever seeing it leak diesel like this one is. I'm confident that it's not leaking from the fittings because the fittings are dry, and the leak stops itself after operating the machine for a while.

Any advice would be really appreciated. Thank you

 

[willie59]

I know you stated that you have replaced the lift pump, meaning it's new, but unfortunately, that little hole is there by design, if the pump fails it's designed to leak fuel from that hole to let you know the diaphragm in the pump is failing. If the hole were not there then you'd never know and fuel would leak into the crankcase contaminating the engine oil. That new pump is going south.

 

[Diesel Dave]

What Willie said !
That is a weep hole indicating that the diaphragm in the pump is leaking.
If the pump is new , the supplier should be providing one under warranty

 

[Sampsonn_]

I know you stated that you have replaced the lift pump, meaning it's new, but unfortunately, that little hole is there by design, if the pump fails it's designed to leak fuel from that hole to let you know the diaphragm in the pump is failing. If the hole were not there then you'd never know and fuel would leak into the crankcase contaminating the engine oil. That new pump is going south.

Thank you. That makes a lot of sense. This is really surprising as the pump came from our local Brandt shop, not some ****** pump off of Amazon. I'm sure they'll replace it, but man that is annoying.

 

[Diesel Dave]

What was the part number of the pump that Brandt sold you.

 

[Sampsonn_]

What was the part number of the pump that Brandt sold you.

Part number is RE42211

 

[Diesel Dave]

Ok good, that’s a legit Deere #.
Some cases Brandt has aftermarket parts on their shelf as well wth Deere part numbers followed by 2 or 3 letters.