Oil leak at fuel pump

Lynn Eades · #1 15-08-14, 01:28

Andrew just something to consider. there is a rudimentary seal under the pump diaphragm. Can I assume you have not checked it. The seal supposedly stops oil getting through to the under side of the diaphragm from where it exits at the breather hole (in the bottomside of the pump casting. It has to have the hole. I do think your main problem is not here though.

rob love · #2 15-08-14, 05:20

Too bad you can't affix an elbow and a small tube so the oil dumps deeper in the tube, below the fuel pump.

andrew honychurch · #3 15-08-14, 10:55

thanks Guys. I stripped it down again yesterday and have identified the oil leak to be more due to the seal between the aluminium pump mounting and the top of the inlet manifold where the pump pushrod emerges. there is a tube pushed into the manifold aperture here and it sits slightly proud causing a bad seal to the aluminium pump manifold. I have mad up a new gasket and applied RTV sealant so am hopeful this will hold back the weeping oil leak which was gradually messing up my hull floor!

I am still slightly surprised that the oil flow seems to be fairly constant through this PSV. Its a while since I applied my mind to this so will need to recheck everything, such as whether I have the flow path the correct way around for the oil cooler lines. I am sure its correct as I would have checked this before. I guess I was hoping somewhere out there is a modification sheet detailing the fitment of this PSV and explaining the operation. I am planning on driving it about 5k today to go to Combined Ops at Headcorn ( will have both the Lancasters displaying over the weekend should be amazing sight) and this should be a long enough drive to open the oil cooler thermostat which would then reduce the flow through the PRV.