pcatterall
Well-Known Member
Since changing our filters we seemed to have picked up a leak which I am having trouble locating/fixing, I wonder if anyone can help with some pointers/advice.
Engine is a 4108 fuel is drawn from bottom of tank, up to top then down to a glass sedimeter then down to a Cav filter with glass bowl then up through the pump to the CAV engine filter.
Engine works fine and will cruise all day but then when lefty to idle for 15mins or so( as in the deepest lock on the RHone!!) gets air in the system and fails and requires full bleeding.
Bleeding in our case entails bleeding at the engine filter ( typically 40 pumps with the hand lever to get fuel through) then we have found that we can go straight to the injectors and bleed them. Presto ...all works fine until our next long period at idle speed.
We had recently replaced both filters and also cleaned the sedimeter bowl so I guess we have picked up a small leak somewhere.
I would have thought, though , that 40 pumps on the pump would indicate quite a bit of air in the system but both the sedimeter and the glass bowl in the first filter remain full of fuel.
Why does the engine work fine at normal revs but fail after a long idle?
Any short cuts on isolating where the leak is ( or just check connects and seals at each 'filter') one by one?
I guess that if there is air getting in at the sedimeter seals this would show in the glass? but at the first filter could the air be in the filter and not show in the glass?
I was not able to get a satisfactory 'bleed' at the sedimeter screw nor at the first CAV filter, these are both below the fuel level but as stated the fuel has to be drawn up to the top of the fuel tank then goes down to these items so perhaps bleeding by gravity wont work?
Any comments on the bleeding of the 'high pressure' side. We used to bleed at all the connections as per the manual but some are very difficult to get at ( and pump as well) We cut down on the places where we bled at until we were just doing it at the injectors. I guess that any air in the HP side will eventually have to come out at the injectors and it only entailed cranking for about 20 seconds in our case.
Most grateful for any advice ( but I do not want to change the whole system at this time !!)
Engine is a 4108 fuel is drawn from bottom of tank, up to top then down to a glass sedimeter then down to a Cav filter with glass bowl then up through the pump to the CAV engine filter.
Engine works fine and will cruise all day but then when lefty to idle for 15mins or so( as in the deepest lock on the RHone!!) gets air in the system and fails and requires full bleeding.
Bleeding in our case entails bleeding at the engine filter ( typically 40 pumps with the hand lever to get fuel through) then we have found that we can go straight to the injectors and bleed them. Presto ...all works fine until our next long period at idle speed.
We had recently replaced both filters and also cleaned the sedimeter bowl so I guess we have picked up a small leak somewhere.
I would have thought, though , that 40 pumps on the pump would indicate quite a bit of air in the system but both the sedimeter and the glass bowl in the first filter remain full of fuel.
Why does the engine work fine at normal revs but fail after a long idle?
Any short cuts on isolating where the leak is ( or just check connects and seals at each 'filter') one by one?
I guess that if there is air getting in at the sedimeter seals this would show in the glass? but at the first filter could the air be in the filter and not show in the glass?
I was not able to get a satisfactory 'bleed' at the sedimeter screw nor at the first CAV filter, these are both below the fuel level but as stated the fuel has to be drawn up to the top of the fuel tank then goes down to these items so perhaps bleeding by gravity wont work?
Any comments on the bleeding of the 'high pressure' side. We used to bleed at all the connections as per the manual but some are very difficult to get at ( and pump as well) We cut down on the places where we bled at until we were just doing it at the injectors. I guess that any air in the HP side will eventually have to come out at the injectors and it only entailed cranking for about 20 seconds in our case.
Most grateful for any advice ( but I do not want to change the whole system at this time !!)
