AC FUEL PUMP VALVES
We planned to drive our Ruby
down to the beach for a New Year’s Day coffee and cake, but it wouldn’t start. I
couldn’t get the fuel to prime on the manual priming
lever. I checked the fuel level in the tank and it was a bit low, so I added a
gallon. Still no luck, so we had to abandon the trip and try to fix the car
instead.
I released the fuel pump input connection and blew
into the fuel tank filler, with the result that fuel poured out, confirming no
blockage in the fuel pipe.
I then released the output connection, took the top
off the fuel pump and filled it with fuel. I put the cap back on and operated
the primer without suc-cess, confirming a pump problem. The pump is only three
years old so I was surprised that it had failed. I checked the diaphragm for
ethanol damage or splits, but it was like new. This led me to checking the
valves.
I tested the valves by blowing and sucking the
respective input and output ports, having first dried them with the air line.
The input valve gave no resistance. As shown in the picture, the fibre sealing
washer had warped, preventing it from seating, so the pump had no suck or blow.
The valves are peened to retain them in the pump body, so I gently re-moved the
peened aluminium with the Dremel tool and a craft knife. I then fitted and
peened to retain two new ones. Now reassembled, the pump makes that reassuring
oooh-aaah sound when operated. Refitted and recon-nected, all is fine again.
Now, off to Milford for that coffee.
Jon Reynolds DA7C