bee utey
8th January 2010, 03:34 PM
It's amazing that a little thing like a fuel pump lasts as long as it does. Recently I sawed open an old AC Delco pump out of a Disco 1 that had failed.
pump.jpg (http://www.aulro.com/afvb/attachment.php?attachmentid=21546&stc=1&d=1262924541)
With the case removed you can see how many bits can go wrong.
The top cover contains the brushes and the non-return valve.
The body contains strong magnets that can attract any iron fragments and jam the rotor.
The rotor end shows how much the brushes have worn into the commutator.
The roller cell is a miracle of precision engineering, any grit in there will wreck it.
The vane pump ensures positive pressure to the roller cell, reducing the risk of cavitation.
All this is protected by a filter sock which goes on the bottom cover.
So it shouldn't be a surprise when one fails at around 150,000km. And of course anyone replacing a failed pump should make sure there's nothing left in the tank which might damage the new pump, otherwise you have to do the job again.
pump.jpg (http://www.aulro.com/afvb/attachment.php?attachmentid=21546&stc=1&d=1262924541)
With the case removed you can see how many bits can go wrong.
The top cover contains the brushes and the non-return valve.
The body contains strong magnets that can attract any iron fragments and jam the rotor.
The rotor end shows how much the brushes have worn into the commutator.
The roller cell is a miracle of precision engineering, any grit in there will wreck it.
The vane pump ensures positive pressure to the roller cell, reducing the risk of cavitation.
All this is protected by a filter sock which goes on the bottom cover.
So it shouldn't be a surprise when one fails at around 150,000km. And of course anyone replacing a failed pump should make sure there's nothing left in the tank which might damage the new pump, otherwise you have to do the job again.