Thread: Series IIa - Fuel Pump problem

Hello all,

I have a problem with my fuel pump. It is the mechanical type. Firstly let me say that the vehicle is a IIa 1968, ex-army long whell base 109 GS, original 4 cylinder petrol. The problem is that if I don't drive it for a couple of days I have to put some petrol down the carby to get the thing started. When I look at the in-line fuel filter (after a coupkle of days) there is no petrol in it? Could the petrol be flowing back down the line into the pump??? Anyway I thought it might be a faulty valve in the pump. So I pulled the pump apart to replace the valves (had a kit at home) I could not work out how to take the old valves out? Do you have to destroy the old ones to get them out?? I was going to use a screw driver to pry them out, but was too worried I would not be able to get the new ones in, because they are held in by small 'lugs' (not right word) which look like they have been punched around the side of the value recess? My manual doesn't give any explanation on how to change the valves? Could anyone please help with some advice.

By the way all other connections in the fuel line a tight with no leaks, and the glass bowl on the tank side of the pump is alway full.

kind regards,
tim - darwin NT

As indicated, older pumps have the screw retained valves, later ones held by being staked. It is possible to remove these by carfully chiselling away the bent over bit with a very small, sharp chisel (perhaps made from a small file) and the new ones retained using a centrepunch.

Normal procedure when it has been standing for a while is to use the priming lever to pump up fuel. If your carburetter is a Zenith, it may be worth checking if the top section has warped so that it does not seal properly onto the bottom part. (This will cause all sorts of other problems as well) If it is warped it can be ground flat using fine wet and dry on a flat surface such as plate glass.

John