This should be easy, but, it has been driving me nuts......engine runs perfectly as long as there is fuel pressure. Stop the engine for more than a few minutes and it requires bleeding. Have two tanks and two separate filtering systems. Problem occurs on either system. Any suggestions? jerry
Yanmar 2gm20-air infiltration
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It is an air leak. The most common might be at any or all of the cursed banjo connections!.. or the secondary filter bowl..or an old and checked hose leading to the secondary filter. Start at the highest banjo connection and and work down.. Before you do, get a new set of the copper gaskets.. Easy to strip so be careful! Good Luck.
Leak
An Air leak for sure and now is the hard part finding it and looking as already mentioned,you have your work cut out so go slow and start checking.
Nick
An Air leak for sure and now is the hard part finding it and looking as already mentioned,you have your work cut out so go slow and start checking.
Nick
Could be worse
A tiny airleak at the water pump of the raw water is often imperceptible and can lead to an explosion of the exhaust hose. It was... fascinating.
A tiny airleak at the water pump of the raw water is often imperceptible and can lead to an explosion of the exhaust hose. It was... fascinating.
Air leak. If the system looses pressure in just minutes instead of weeks the leak is large enough and should be easier to track. Look for a fuel leak beyond the primary filters. Check the underside of the lift pump, secondary filter, all lines and connections leading all the way to the injectors. More than likely it is the banjo connectors as others have pointed out.
use your nose
If the air leak is in the pressure side then the leak will be visible. Since you have looked and don't appear stupid we will assume the pressure side is OK. That leaves the suction side. aka tank to first pump.
Use your nose to sniff for a fuel smell. Get your nose right down on the hose. And yes, it is undignified so don't have a camera handy for capturing that Kodak moment.
If the air leak is in the pressure side then the leak will be visible. Since you have looked and don't appear stupid we will assume the pressure side is OK. That leaves the suction side. aka tank to first pump.
Use your nose to sniff for a fuel smell. Get your nose right down on the hose. And yes, it is undignified so don't have a camera handy for capturing that Kodak moment.
2GM20F fuel leaks
The usual culprit for me was always the nylon washer on the bleed screw on top of the Yanmar filter canister, but if you want to take care of it in shortest time, replace both bleed screw washers and all the banjo fitting copper washers on the low pressure side between the high pressure pump and the manual lift pump, and put a new 'O' ring in the top of the Yanmar filter canister. You may also have stripped the threads where the bleed screws enter the fuel filter; that may be fixable if both are not stripped as I've sealed up one of two bleed screws with epoxy putty as a temporary repair that has lasted years.
If the leak were on the high pressure side you should be seeing noticeable diesel fuel at the leaking point(s).
The usual culprit for me was always the nylon washer on the bleed screw on top of the Yanmar filter canister, but if you want to take care of it in shortest time, replace both bleed screw washers and all the banjo fitting copper washers on the low pressure side between the high pressure pump and the manual lift pump, and put a new 'O' ring in the top of the Yanmar filter canister. You may also have stripped the threads where the bleed screws enter the fuel filter; that may be fixable if both are not stripped as I've sealed up one of two bleed screws with epoxy putty as a temporary repair that has lasted years.
If the leak were on the high pressure side you should be seeing noticeable diesel fuel at the leaking point(s).
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