A breakdown that could have had serious consequences
Croque soleil janine and Georgess's ship is in the middle of the Antioch Peninsula. Not a breath of wind, the rising current propels them right into the middle of the cargo channel, with no room for maneuvering. And when it's time to start, there's nothing we can do.
- Georges, where do we keep the spare diesel filters?
- In the trunk of the port bench seat.
- Okay, what about the filter wrench?
- It's in the toolbox in the front peak.
- It must be the clogged diesel filters. We didn't winterize the boat properly when we left last winter.
- Yes, it's a good thing we have emergency filters.
- Replace them, I'll watch over the bridge.
Georges dismantles the pre-filter, finds a sort of gelatin and a lot of dirt inside. The failure is confirmed.
- It's all right, Janine, I've got it. They were clogged! I've replaced them and we're good to go.
- Have you purged the circuit yet to restart?
- Oh no, I never knew how to do that!
- All right, you go up to the lookout, I'll purge.
Janine opens the filter bleed screw and activates the priming bulb. Diesel begins to fill the new filter until it overflows through the bleed screw.
- Hurry up, Janine, I can see a cargo ship in the distance.
- All right, go ahead and start!
Georges operates the starter push-button. This energizes the solenoid coil, moves the plunger core and makes contact with the starter motor's power circuit. Simultaneously, the fork tilts and pushes the drive pinion, which engages the teeth of the flywheel. The motor turns and... Does not start.
- Wait, I'm having trouble bleeding. I'll bleed the injection pump!
- Yes, but hurry, the cargo's getting bigger!
- Go ahead and start
VRROOOUUUUMMMM
The engine starts, the boat is propelled again, and resumes its course.
Why does the diesel filter clog?
Clogged fuel filters are a widespread problem. The cause is a tank that contains bacteria or has accumulated various deposits. Deposits are dust deposited by: a dirty funnel during filling, an unsuitable canister used to transfer fuel, an improperly winterized tank... Once the fuel filter is clogged, it blocks the engine's fuel supply and causes a breakdown.
Monitor fuel quality and check the tank
To restart the engine, it must be refueled. In this case, as the fault is the clogged pre-filter, we'll try to remove it and replace it. It's the first to be exposed to dirt in the tank, and therefore the first to clog and collect impurities. Located upstream, most of the dirt will accumulate there, and can give an idea of the tank's condition. The engine's diesel filter should also be replaced as a preventive measure.
However, even further upstream, the tank may still be dirty or contaminated with bacteria. Replacing the filters in this case will only temporarily, if at all, solve the problem. As the dirty tank is the cause of the malfunction, it will clog the filters once again, preventing diesel fuel from reaching the engine.
To see if the tank is dirty, it can be inspected through an inspection hatch, if present. In this case, cleaning is simple: empty the tank completely and remove any deposits from the bottom. If there's no inspection port, the pre-filter should be checked regularly to make sure it's not collecting too much dirt. If the pre-filter clogs up too quickly and causes the engine to stop running, you'll need to clean the tank by installing an inspection hatch.
Changing diesel filters
If the tank is higher than the pre-filter when you remove it, the fuel will flow by gravity indefinitely. It's important to place a container under the pre-filter, if there's room. If not, place an absorbent cloth at the bottom of the bilge, as some diesel will spill over.
Dismantling the diesel pre-filter
When reassembling the new filter, put a drop of oil on the gasket so that it will loosen easily the next time it's dismantled, and tighten by hand. By hand: without using the filter wrench, otherwise it will be virtually impossible to dismantle, and as we've seen, in an emergency situation, it's useful to know your boat well and be able to intervene quickly!
Re-priming the circuit
Once the fuel filters have been changed and the fuel tank cleaned, the engine can be restarted. It's time to bleed the fuel system, a subject that would merit a full article. You should also check that there are no fuel leaks in the system, especially at high engine speeds.
Avoid clogging
To prevent the reservoir from accumulating deposits again, you must :
- use the cleanest fuel possible
- check the condition of funnels, giving preference to those with a sieve
- use clean cans to transfer fuel.
Finally, to prevent the growth of bacteria in the tank, it should be kept full as often as possible. Condensation causes water to settle to the bottom of the tank, especially when the boat is winterized. An anti-bacterial additive can also be used as a preventive measure.
