Hi All, I hope you are all doing well and getting back out on the water. I have a 1999 Catalina 380 with a Westerbeke 42b diesel. My boat was launched today and when I started my engine commissioning tasks I noticed there was about 2 gallons of diesel had leaked into the engine compartment. I checked the fuel tank and water separator and there where no cracks or leaks. I cleaned out the leaked fuel but I still haven’t identified the leak point. Has anyone had a similar issue? Any ideas on how to determine the root cause would be appreciated!!!
Diesel fuel leak
- Thread starter shea0613
- Start date
Funny you should mention this, I've spent a lot of time today replacing fuel lines. If the fuel lines have not been replaced, they are probably leaking. The first time I had a leaking fuel line it was a very slow drip and I did not discover it for a while and ended up in your position, a bilge full of diesel.
First thing, shut off the fuel if you have a shut off valve. Next trace all the fuel lines and look for damp spots and drips. Next buy enough fuel hose to replace all the lines and use good smooth band hose clamps. Be prepared for surprises as you do this, like ¼" hose jammed on 5/16" fittings.
If you find one leak now, there will be more later. The cheap big box HW store hose clamps will cut into the fuel line and cause more leaks, do the job right.
Simplest way to find a fuel leak is to pressurize the line. Take the suction line off the filter to the tank and use a bicycle pump to pressurize the tank. No leak, move on from there.
How can you pressurize the tank if it has a static vent? I am assuming you are meaning close the fuel valve at the tanka and pressurize the fuel line to the tank?
Do you have an aluminum tank? I had pinhole leaks and thin spots in the bottom of the tank and it was "seeping fuel". I ended up having a new, thicker walled aluminum tank made by Ezell in Florida (the OEM tank maker). They are still in business and have the original tank drawings.
Put some paper towels around the bottom of the tank and see if they get damp.
Put some paper towels around the bottom of the tank and see if they get damp.
Is there a fitting to this vent from the tank? Could you remove the hose and putin a pipe plug
That would work. It might be a good idea to do both. Pressurize the line first from the fuel filter to the tank shut off valve and see if there is a leak in that line. Then, if you can seal off any vent or open path from the tank, you can do it again with the valve open and see if the leak is in the tank. With it pressurized you may see an accelerated leak if it is weeping from a pin hole leak or porus area in the bottom of the tank.
When I took out my leaking tank, there were some areas that were damp thin spots so soft it felt like wet cardboard when I probed it with a sharp pick. It punched right through with no pressure.
When I took out my leaking tank, there were some areas that were damp thin spots so soft it felt like wet cardboard when I probed it with a sharp pick. It punched right through with no pressure
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Very true! The made mine with a thicker aluminum than the original, added an extra clean out and an extra pickup and return in case I wanted to install a fuel polishing system. They will work with you on any changes you want to make to the original. Price was reasonable (in boat buck terms anway), arrived quickly and fit like a glove.
The fuel supply system has 3 basic parts, storage, supply/suction, and pressure. It will easy to trace the leak with a little logic and planning.
Was the fuel leaking before launch? If not, then the leak is not in the tank or the PO was incredibly unlucky and the leak started right at launch.
Is the fuel leaking after the engine is shut off? If so, then the leak is likely in the supply/suction side of the lift pump, somewhere between the tank and the lift pump.
Does the fuel only leak while the engine is running? The leak is on the pressure side of the lift pump.
Time to get a bright flashlight and go exploring. Check at the fittings for dampness. If you don't see any, have someone start the engine and look for squirting fuel. wear safety goggles. The leak will become quite apparent.
Fuel hoses don't last forever. They dry out, crack and leak. If you have one leak more will be following. Replace all the hoses with good solid band clamps.
Was the fuel leaking before launch? If not, then the leak is not in the tank or the PO was incredibly unlucky and the leak started right at launch.
Is the fuel leaking after the engine is shut off? If so, then the leak is likely in the supply/suction side of the lift pump, somewhere between the tank and the lift pump.
Does the fuel only leak while the engine is running? The leak is on the pressure side of the lift pump.
Time to get a bright flashlight and go exploring. Check at the fittings for dampness. If you don't see any, have someone start the engine and look for squirting fuel. wear safety goggles. The leak will become quite apparent.
Fuel hoses don't last forever. They dry out, crack and leak. If you have one leak more will be following. Replace all the hoses with good solid band clamps.
My leak was from my old Ezell tank. To my surprise they still had blue prints for
my 1993 tank. Check for their label on top of the tank if it turns out to the issue.
And as previously stated, the new tanks are made thicker. New fuel lines are
inexpensive. Cheap insurance. Remember that there is a return fuel line also.
I placed a primer bulb between the tank and first filter. It makes bleeding the
system easier.
my 1993 tank. Check for their label on top of the tank if it turns out to the issue.
And as previously stated, the new tanks are made thicker. New fuel lines are
inexpensive. Cheap insurance. Remember that there is a return fuel line also.
I placed a primer bulb between the tank and first filter. It makes bleeding the
system easier.
Thanks for all the responses. I went back to the boat today. A very small amount of diesel was back in the bilge. I checked the fuels lines and they are clean with no cracks or stress showing. I started the engine and observed no leaking or diesel spray. I did observe a very slow drip (about every 40 secs). It was coming from the bottom of the engine section next to the transmission. I can’t tell from the manual which part this is. It’s rounded at the bottom. Reaching under I can feel a tiny hole where I think the slow drip is coming from. I believe that the drip probably existed last season and over 6 months since decommissioning it built up to the 2 gallons I pumped Out
yesterday. Not sure if a tiny hole can be fixed or if I have a bigger problem. If anyone has experienced anything similar please share on how it was resolved. Much appreciated!
yesterday. Not sure if a tiny hole can be fixed or if I have a bigger problem. If anyone has experienced anything similar please share on how it was resolved. Much appreciated!
Sounds like it is the lift pump. If it is a slow leak, it might be somewhere else with the fuel just running down the hose to a place where it can drip off.
My Westerbeke was leaking fuel around the area of the tranny. The lift pump was the culprit. Rust created a pin hole. Very easy to replace.
I found 2-3 gallons in my bilge as I was about to pushback for a 3 day single hand trip. My fuel tank(aluminum and factory) has generated a pin hole in its floor. It had been leaking for a long time and finally got big enough or the tank shifted to allow a significant leak. The 1” plywood it was mounted on was saturated. I could smell diesel the year before while sleeping in the quarter berth but could find a link....found it.
Timing is everything. Finally had access to the boat only to find the bilge full of diesel fuel. Luckily i had placed fuel absorbent pads from the bilge trailed all the way to the tank. Expecting a possible leak from a line. A leak ended up being the tank itself, pin holes at the bottom. Tank on order from the original manufacturer,EZELL. Hoses will be replaced. Lines and tanks are year 1999. Learned from this. Place small pieces of pads everywhere to easily find leaks, prior to it leaking.
Good luck.
Good luck.
