I am cursed.
There can be no other explanation - once again my Air Pump has had to be re built.
The full story, except for this latest episode, spans three threads on this forum -
The Beginning -http://www.nswcorvettes.com.au/forum/viewthread.php?tid=721#pid1045890006
First problems
http://www.nswcorvettes.com.au/forum/viewthread.php?tid=791#pid10458902932nd Problems -
http://www.nswcorvettes.com.au/forum/viewthread.php?tid=830#pid1045890527The result of the last fix is that it worked fine for a year. My 88 vette is my daily driver and during that time I did a trip to Brisbane so all up about 4 to 5000kms.
Then recently I noticed the pulley was a bit loose. On inspection it was found that the front bearing had begun turning on the shaft - which is 17mmm diameter - no-one could tell me why a large 40mm OD bearing would prefer to turn on a 17mm thick shaft when it was in good condition with freely moving bearings.
After a lot of thought the only conclusion I could come up with was that the shaft was expanding and putting a lot of side force on the bearings - my friend in Brisbane had the same problems with the bearing turning on a hardened shaft, and it was his rear bearing that let go in his re-engineered pump.
I wish now I had just bought a replacement GM pump from the US - currently this one has cost me something like $600 - plus the worry and drama's.
This time I've had another new shaft made, same big bearings, but the rear bearing is held in with a wave washer, which should allow for a small amount of shaft expansion.
The only problem I forsee with that, is the rear bearing may eventually wear a little loose in the housing from moving back and forth all the time - and time will tell, I have my eye on it!!!
Will this piece of cunning engineering lift the curse??
S'nut