Series IIa - Fuel Pump problem

[btm]

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

[vnx205]

When my Series III had a similar problem, I used to operate the manual lever on the pump before attempting to start it. A lot simpler than pouring petrol down the carby.

IIRC, some fuel pumps had the valves held in by screws and it was easy to fit new valves. Others had the valves held in by a "lug" as you called it punched into the housing. I don't think you could do much with them.

However you would do well to wait for someone with a better memory than mine to confirm that. I just wanted to suggest the idea of tickling the manual lever on the pump.

[dandlandyman]

Early (Series 2) mechanical fuel pumps had bolt-in valves, which certainly make it a bit easier to replace them. Maybe Massey-Ferguson top-halves are the same, can't say for sure. I recently fitted an electric fuel pump under the seat, before the mechanical pump, to give the system a boost when starting from cold after a few days and when the fuel in the lines 'vapourises(my explanation)' on extra hot days. I have an extra dash switch to control it. That setup may be useful in your case, too. It's quite normal for fuel to drain back to the tank over time, I even encountered it when I had my KE20 Corolla.

Dan.
69 2A 88" pet4, 74 3 109" pet4, 68 2B FC pet6.

[JDNSW]

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