For a while now the AC fuel system has been extremely temporamental. At times it works great, other times it starves the carb of fuel, and when left overnight the fuel drains back into the tank. It was noted that this could be signs of pump failure, and the garage later confirmed that during the MOT.
Just this evening, I got around to replacing the pump. On this AC at least (can’t vouch for the 130 others 🙂 ) the pump is wedged between the alternator and the end of the engine. With about 4 inches of space to work around, it’s a bit of a pain. On the oh-no-o-meter, it’s about 7.5/10. Whereas the TR6 and the Land Rover pumps are down at around 3.
Firstly, remove the bolt at the bottom of the alternator. This is the adjuster bolt, and the adjustment arm will drop away, allowing the alternator to be swivelled in a bit to remove the belt. Next up, remove the two bolts at the top of the alternator that attach it to the mounting frame. Swivel the alternator up and over and rest it on the manifold or heatshield.
Now that the alternator is out the way, you can get access to the bolts that hold the alternator frame in place. There’s one bolt into the block, and another 3 (!) down the front of the timing cover. Remove the top two bolts, and loosen the lower one. This will allow the frame to be swivelled backwards and out of the way to give you access to the fuel pump.
Remove the fuel pump simply by removing the two bolts (and optionally the stud, if it chooses to come out first), and slip the pump off. Prepare the surface on the block, remove the remains of the previous gasket, and generally tidy up the surface. You don’t want any oil leaking out of here. Put on a coating of Hylomar Blue on the surface of the mount and the pump, put the gasket on (make sure it’s the right way up), and then bolt the two together.
In good old Haynes fashion, refitting is the reverse of the removal. Line up the alternator mount/frame, stick the bolts in loosely, and then put in the last, small, bolt that holds it to the block. Once that’s in place, tighten up the remaining three. This leace the alternator free to be mounted, the belt to be put on, the adjustment arm to be connected, and off you go.