Monday, June 1, 2015

Diesel tank cleanout

Replacement filter


It started innocently enough. Actually, to be accurate, it didn't start.

It was a peculiar thing. Shackleton performed brilliantly on my delivery cruise up the river two weeks ago. Eight hours of cruising with several stops and starts and it worked flawlessly.

Two days later, I crank her up and she runs for 20 seconds and dies. Odd.

My first diagnosis was that there was probably something (either water or dirt) clogging the fuel filter. It had been a particularly rough day on Grand Lake when we came in to the harbour and I figured that it had probably just soiled the filter when the sediment in the tank sloshed around.

I drained and cleaned the primary filter. No luck.

I replaced the secondary luck.

I bled the system. I bled the system. I bled the system. No luck.

Since I am new to the wonderful world of diesels (previous engine was an Atomic 4) I figured that I was doing something wrong in the bleeding process (even though the manual on the Vetus M4.15 says that it is "self bleeding".

After many hours of unsuccessful bleeding attempts I decided to actually think through the problem...

Lesson #1 - Stop and think. (sure, it seems obvious now!)

A bit of experimentation finally lead me to figure out that I wasn't getting any fuel from the tank. (another sailor had actually mentioned this as a possibility early on...and I had quickly forgotten about it).

Lesson #2 - Really pay attention to what the experienced sailors say!

I removed the access hatch for the tank and quickly realized the root of the problem.

Goo filled bucket
Lesson #3 - Make sure that whatever you use for a gasket on your fuel tank is actually compatible with diesel fuel. The previous owner had not. He had used some sort of a rubbery material that had since partially dissolved. This partially dissolved goo was now all through my tank. Little black jelly bean sized goo pieces had lodged themselves into my intake hose.

The fix

  1.  I removed all 40 gallons of fuel into jerrycans. The last 2 cm at the bottom (where the sludge was mostly), and the sludge, was removed into a separate container for disposal. I used a borrowed diesel lift pump hooked to my battery to pump out the fuel. This was a slow process. I used cheesecloth over the end of the suction tube to keep it from getting clogged. 
  2. I cleaned the tank. I scrubbed it with rags and used a porous sponge to sock up the grime and sludge. I rinsed the tank with more diesel using the lift pump in reverse. 
  3. I disconnected and blew out the intake hose. Not to self...bring an air pig for this. Diesel tastes terrible!
  4. Tested the engine...and it worked!
  5. I made a gasket out of 2mm cork.
  6. Using a Sue Grafton novel of my wife's (haven't told her this yet) as a drilling backer I pre-drilled the gasket holes.
  7. Re-installed access plate
  8. Sue Grafton brand drilling backer
  9. Cleaned up all of that diesel that I had carefully tried not to spill.

Hopefully my cork gasket will last for a few years without turning into another mess. The inter-webs assure me that it will be ok.

The positive outcome from this ordeal is that I now have a much better understanding of my fuel system. 

Completed access plate with gasket
Asian strainer with cheese cloth for removing chunks

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