BMW E39 diesel pump replacement
Symptoms of failure: poor starting/cutting out when the fuel level falls to around a quarter of a tank.
Cost: £42 from GSF, plus 2x 9mm petrol hose clips (the originals are not reusable).
Procedure: remove the rear seat base by pulling up sharply on it's front edge (there are a pair of spring clips holding it in place). Beneath are 2 access panels to the tank, the pump is under the right-hand side one (behind the driver on a UK right-hand drive car). Remove the cover and disconnect the 2 hose connections and the electrical plug (removed by pushing the locking clip sideways). Unscrew the locking ring by gently rotating it with a hammer and chisel.
Now slowly remove the fuel sender unit, noting it's orientation and how it slots into the pump assembly below - it's all fiddly and overcomplicated! It takes a bit of manipulation to get it out without damaging the delicate float assembly.
You will be able to see the pump down in the tank now; note it's position. Compress the 2 clips on either side of the black moulding to release it - it should look like the photo above. Unplug the wires from the pump (they're different widths so you can't get it wrong), and disconnect the hose. This was the most difficult part for me - I suspect the hose was soft and pliable when new, but it's now hard and would have fractured if I'd not gently pushed it off with a flat-blade screwdriver.
There's a filter attached to the bottom of the pump, note it's position then unclip it (else it'll fall off when you remove the pump and you'll spend 10 minutes figuring out how it fits...). Now remove the pump from the assembly - it comes out of the top, but I had to use 3 flat-blade screwdrivers simultaneously to prise the clips open.
The new pump slotted straight in, but the hose orientation was different and I had to trim a bit of plastic so the electrical connections would fit. Then it's a case of refitting the filter, slotting the assembly back into the tank, then persuading the sender unit back in. I found it easier to install the seal into the tank first, then slotting in the sender.
With the sender correctly orientated (there's a slot) it's just a case of putting the lock ring back and connecting everything back up. Switching on the ignition powers up the fuel pumps, and it took about 60 seconds for all the bubbles to disappear from the transparent pipe coming out of the fuel filter under the bonnet. Then it started. Lovely.
