How to break a Cummins 6BTA Lift Pump?
 

I have a 1997 Cummins 6BTA. We have been from New England to Florida, all around the Mediterranean, through France, Germany, Netherlands, Belgium, and England for the past 15 years with nary a glitch.

Now: I arrive in Chichester, England and hire the local to "winterize" the engine: change filters, change oil, change antifreeze. He does all that and now the engine won't start.

Many hours of agony (I'll spare you the details) and he declares the lift pump is broken. Gosh, it was working only a few hours ago...

So how can he break a lift pump? The manual says the hand priming lever has to be in the upright and locked position before starting the engine. He had it down. My guess is that that stripped the gears that the cam engages to run the pump. But I haven't found any such confirmation?

What do you think?

He reports that he's replaced the pump and the engine now runs. But the machine is 3000 miles away so I can't check right now.

Thanks in advance.

Cheers, Andy
MV Pilgrim.

were you there to see it not start in person? jw because you say its 3000mi away.

Yes, thank you.

The details I was sparing you all are:

1. Fuel tank feeds duplex Racor fuel/water separator complex. Replaced these, fully primed with fresh fuel.

2. From thence to the fuel filter. Again primed with fresh diesel.

3. From thence to lift pump. Manually flexed to draw fuel from the precedents. Except, since he was
the mechanic and I not I left him to it.

He did all this but left the flex lever on the lift pump in the DOWN position, not the UP and Locked position. So when he complained and I came to investigate I found the lever in the down position.

4. He then proceeded to loosen all the fuel lines along the way, ensuring that fuel was coming out at each juncture, including the fuel injectors, presumably the last step in the path. So the fuel was getting through, but not being pumped.

So I said leave it for the night. Maybe it is just flooded. (Can you flood a diesel? I would think not, since it is just heat of compression, not ignition, but whatever. It was time for him to go home and me to take a G&T.)

I spent several hours of the evening reading through the manual. No clue of anything, nor a picture of the lever/cam/lift pump complex, just the warning to have the lever in the UP and locked position, which it had not been when we first tried to start the engine.

But the next morning the same sequence, and then he noted that the flex lever didn't give the sort of resistance that he expected. I checked it and agreed. It was a limp willie.

But at that point we had to haul the boat for me to see the bottom and then for me to go to the airport for my flight.

So we confirmed there was little or no fouling, the zincs were almost as new (which raises the question of bonding - another issue for another forum) and then off I went to the airport.

Subsequently they have claimed to have fixed it by replacing the lift pump. But I'm wondering why it failed.

I have engaged a certified Cummins engineer to address these issues, but wanted your opinion. I'm not going to sue anyone, but they need to be taught. We all win or we all lose.

Thanks for the reply.

Cheers, Andy