Perkins Fuel Leak

I am still searcing for the source of a small fuel leak on my Port engine.* After a 6-8 hr run, there is maybe a*cup or so of fuel in the fiberglass engine pan.* I have been down in the engine room while underway searching for the source and am still baffled.* I do recall a post here that mentioned low sulfur fuels causing leaks at injector pump, but this does not appear top be the source.* Using oil absorbent towels, I was able to determine that the leak is dripping from the bottom of the oil pan, and appears to orginate on the Port side of*the engine.* Any advice before I call in the Pros?*

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More than likely dripping from the inj pump or fuel filter or plumbing and running down the side of the enigne an "appearing" to be from the oil pan.

I would suggest wiping everything down to super clean then trace it from there. Maybe idle the enigne for 10 to 20 minutes and shut down then look before everything gets saturated with fuel.

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You didn't mention which engine. *I'm guessing 6.354?*

Wow, not much of a leak. **Did you have your filters changed recently?*

Probably not coming from the high pressure side of the fuel system, but I would still check it and the oil return lines on the injectors.

I would start at the lift pump and run my hands all over it and the fuel lines up to the secondary filter. *Check the banjo fittings at the filter and run your hands around the secondary filter element, top and bottom cap. *The secondary filter, ring gasket, tightening bolt and seal are notorious for leaking.*

If you have oil on the engine already, a small drip like that may be hard to spot. In which case you need to clean / wipe down the engine first.

Yes, they are the 6.354's. I changed the filters around 100 hrs ago. I'll wipe down the engine and check again. The tough part is that all the likely spots for a leak are on the outboard side, next to the fuel tank. Not a lot of room to squeeze in and observe.

Max Simmons wrote:
Yes, they are the 6.354's. I changed the filters around 100 hrs ago. I'll wipe down the engine and check again. The tough part is that all the likely spots for a leak are on the outboard side, next to the fuel tank. Not a lot of room to squeeze in and observe.

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*That's why they make mirrors

Max Simmons wrote:
Yes, they are the 6.354's. I changed the filters around 100 hrs ago. I'll wipe down the engine and check again. The tough part is that all the likely spots for a leak are on the outboard side, next to the fuel tank. Not a lot of room to squeeze in and observe.

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Lay some oil absorbent pads under the engine so you can at least determine which side it is coming from and about how far back on the block.

The two areas I usually will have leaks from most often are:

The fuel outlet line where it leaves the lift pump - No gasket there, just a little flanged end on the metal pipe. *If they are under tightened they will leak and over tightened it will crack the flange, leak, and then must be replaced. Of course if this is the Starboard engine, that would be on the outboard side. *Murphy's Law!! *

Either the gasket on the tensioning bolt or fuel filter canister gasket on the secondary filter. Both can be a problem.

Am I "hearing" the leak started after you changed your fuel filters?

A couple easy ways to find any kind of leak.* The first is a bit expensive, but foolproof.* You can buy a kit that has a floruscent die you add to your fuel, oil, coolent, or transmission fluid.* You run the engine for a bit, then use the included black light to look for the leak.* Anywhere the die leaks will stand out clearly. Try looking at an autoparts store.

A second, less expensive method is to sprinkle talcom powder around areas you suspect are leaking.* Clean and dry the area, then sprinkle the powder.* Any leaks will quickly show themselves.............Arctic Traveller

We use the Tracerline product and it is a very good approach. The more concentrated the dye is will improve your success rate of identifying the leak. I would suggest adding a small "all in one" bottle straight to your Racor rather than adding it to the tank where it will become so diluted. Also you will be able to locate it easier with the higher wattage UV lights.
http://www.tracerline.com/dyesforfluids.html

Max, as asked earlier, are* you sure this is not related to changing out your fuel filters. I'm not saying this is the case here, but all too often problems and recent maintenance go hand-in-hand.

No, started before I changed the filters. Since the leak did not change with the filter change, I've eliminated them as suspects for the time being.

A wise troubleshooter would check the filters again. At least I would. I have the T shirt.

Since the CAV injection pump's input shaft is internal to the engine, it's not likely any sort of "low*sulfur fuel" problem.

There are a couple of bleed screws on the side of the pump for getting rid of air - check them for tightness.

There's a fuel return line that comes from the top of the fuel filter (at least on my engine) - you might want to check it for looseness or chafing.