Need help with fuel leak problem.
OK, now it is a day later. Does anyone know if the maintenance meter that is mounted to the face of the transfer pump on my 951C is supposed to fill up inside and actually run in diesel fuel? I thought that I replaced the transfer pump shaft seals facing in the correct direction. Now I am doubting myself. I am posting the pump break down from the parts manual hoping for your feedback. I think that I might have one of the seals listed as part # 6 in backwards causing more pressure on the meter than it should have. If so, that would explain my fuel leak from the meter window.
Also, on the seal that is shown as part # 17. As I see it, the pictured rubber sealing lip is not facing the direction from which the pressure is coming from. What am I not seeing or understanding when I look at seal # 17 in the schematic ?
After really thinking about the seals and how they are arranged and situated in the transfer pump, if they are not installed facing the right direction, or if they fail, the pump could easily inject a steady stream of diesel fuel directly into the crank case via the geared pump shaft.
As far as how the seals came out of the pump, I can't rely on that. It was leaking when I bought it and I am not the first one to be working on the leaky gage problem. If it turns out to be a backwards seal I need to correct it. If the problem is indeed poor design of the meter and leaky window, I can machine a dummy meter with no window to replace it. For those in the know, your help and experience will be appreciated.
After studying the schematic it appears that the double #6 seals install as I have drawn by hand and posted. If my drawing is correct, then I do have a seal in backwards.
As far as seal # 17 goes, It seems to me that the rubber lip should face the pump gears and oppose the pressure. If indeed the schematic is right, then I have that one in backwards also.
lastly, what kind of sealer can be used (conservatively) on the machined surfaces as they are bolted together with no gasket and there is no gasket called for. I know that I don't need any of the sealer to migrate into the injection pump. I tried Permatex Form A Gasket. It is supposed to stand up to gasoline and diesel fuel, but diesel fuel will dissolve it on contact.


