TN 75s fuel leak

[Harry in Ky]

I'm looking at a TN75s with a fuel leak on the injection pump. It's a Bosch rotary pump with what I refer to as an aneroid on top. I'm not quite sure just exactly how this works. I know it has a tube connecting it to the intake, and uses boost pressure to affect pump operation in some way. On the back of this aneroid is what looks like a vent of some type. There is a steady stream of fuel escaping while the engine is running. Enough to make a mess and needs to be corrected. Does anyone know what might be involved in this? I suspect some seals, o rings and such, possibly a diaphram and more. Have never been into one, so I'm counting on someone out there having some experience, and hopefully some info on what's involved. I hope it can be repaired without removing the pump for major work. Any thoughts?

 

[RickB]

Typical fault of that particular Bosch pump. We send a BUNCH of them to an authorized Bosch pump shop for repairs, most were done under the 5 year EPA warranty. Can't help you with particulars other than to say you should be taking advise from somebody at an injection pump shop or who otherwise can advise you correctly. I don't see that as being an in situ repair due to the location of the leak. Removing the pump from the tractor is a precise operation that requires lock timing the pump prior to removal.

 

[Justinlrmo]

Did you have any luck changing the diaphragm or did you change the whole pump? I've got a 2002 tn75s that is doing the same and wont start on it's own any longer.

 

[RickB]

The discussion above was about the injection pump. I have never changed the diaphragm in a lift pump, New Holland does not sell parts for the pump. $75 for the pump or $90 per hour plus a kit to rebuild it? That’s the choice at a dealership. Not charging shop labor rates could change the economics of your decision.