Fuel pump - catastrophic failure

[JimmyDubai]

See the picture below; it belongs to a Mercruiser Big Block V-8 7.4 lt mechanical fuel pump that failed yesterday while underway; it parted in two pieces!! How on earth this could happen? believe it or not the diaphragm is still in good condition so I managed to sail the last couple of miles at idle to my temporary destination. What could have been the cause? This pump was replaced just 6 months ago so a new one is apparently coming as warranty.

 

[northern]

One of my fuel pumps failed a few years ago. I replaced it with a non OEM one. It failed 160 hours later. We were on our way north and were able to get a non OEM pump sent to us. It failed 100 hours later. I got an OEM one and it has been good for 800 hours so far. The case never cracked but the rivet holding the diaphragm failed twice. The one that failed was on the starboard side and there is 8" of space to work in between the engine and the fuel tank. To hold the push rod up in the engine pack the cavity in the engine with wheel bearing grease then push up the push rod that works the fuel pump. It is easier than trying to but a shim in when you slide the pump in.

 

[JimmyDubai]

Ok, so Mercruiser sent me a new pump so all is good now; hope it lasts!!!

 

[BillK2632]

20yrs of vibrating the way a mechanical fuel pump does, they eventually fail. but I wold say you got a pretty good service life out of it. Probably the last one you will have to change.

 

[JimmyDubai]

20yrs of vibrating the way a mechanical fuel pump does, they eventually fail. but I wold say you got a pretty good service life out of it. Probably the last one you will have to change.

Wait, what!! 6 months a long life?

 

[BillK2632]

Wait, what!! 6 months a long life?

Sorry - did not catch the 6mos part, NO!, these things should last a long time. I hope Mercruiser replaced this at no charge.

 

[northern]

I got one for free but the cost to put it in was $400.

 

[JimmyDubai]

Same thing over here; they charged me $138 but berth fees for 2 nights for $277 as I had to leave the boat 15 miles from my home marina.....