AIR PUMP

Stingraynut · September 11, 2005, 10:09:34 AM

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#pid1045890293

2nd Problems - http://www.nswcorvettes.com.au/forum/viewthread.php?tid=830#pid1045890527

The 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

77CVT · September 12, 2005, 01:10:56 PM

Dude - just buy an eliminator bracket! ;-)

I hope this time it is fixed for good!

Stingraynut · September 12, 2005, 02:52:23 PM

I hear you - but I've got my stubborn head on at the moment !

(there it is -over on the left)

S'nut

MJ427 · September 13, 2005, 02:57:07 PM

mine did the same on a run recently so i am bowring one of VO till i sought it out

Vette Obsessed · September 13, 2005, 05:16:43 PM

QuoteOriginally posted by MJ427
mine did the same on a run recently so i am borrowing one of VO till i sought it out

;41 It was on Stingraynut's car for a while before I lent it to you... That pump has been around. ;35

Stingraynut · September 13, 2005, 05:41:44 PM

The loan was very much appreciated VO ! It's a pity I returned it, could have used it again last week!!

MJ427, was yours an original pump? and if so was it the rear roiller bearing that gave out ?

I'm still collecting data about why mine, which has no cage inside now, just a steel shaft, is going through bearings so quickly - I hope this wave washer is 'the' fix.

S'nut

Vette Obsessed · September 13, 2005, 06:07:39 PM

QuoteOriginally posted by Stingraynut
The loan was very much appreciated VO ! It's a pity I returned it, could have used it again last week!!

No problem Stingraynut, I thought the same thing when I read your post. If you decide to go the air pump delete route I might be able to help you out in the next month or two. Email me if that is the case. :22

Stingraynut · September 13, 2005, 11:30:48 PM

Thanks VO, email me with your plans - what are you about to do? something interesting I bet!!

S'nut

TIPPA · September 14, 2005, 07:20:59 AM

I know knothing about air pumps so this may be a silly question... If your fan belt is too tight could it lead to bearing failure?

Stingraynut · September 14, 2005, 08:08:42 AM

Hi TIPPA - Yes, that could be a factor - except that the tensioner sets the belt tension, so assuming you have the correct belt, and the tensioner is between it's marks, everything is as it should be.

And once the tensioner gets old, there's less tension on the belt.

In the case of my original pump, it was the rear bearing that failed. I would expect excess belt tension to more likely damage the front bearing.

I think the failure of the original pumps is probably a result of how many miles the car has done, and that, like many other parts, they just wear out.

The failure of the re-engineered ones is a different matter.

S'nut

daniel42au · October 21, 2005, 08:34:17 PM

This AIR pump is a waste of oxygen.... all it does is pump "air" into the exhaust after the O2 sensor but before the cat converter.... what a waste of oxygen.....

repairing the sucker is a waste of money.... now that the limit on personal internet purchases has been raised to $1000 (cost of item + shipping) before it gets to go thru customs.... ie no customs duty or gst apply if the total cost is under $1,000.

Stingraynut · October 21, 2005, 11:19:43 PM

woooooaahhhhh!! - daniel42au -

quote -"now that the limit on personal internet purchases has been raised to $1000 (cost of item + shipping) before it gets to go thru customs" -

When did that happen ?? I'm so glad if it did, the GST was much higher than 10% and was equal to duty, I've been hit bad, in the last 2 1/2 years - when did things change????

quote - "repairing the sucker is a waste of money.... "- I absolutely agree with you -which is why mine is changed to just be a free wheeling pulley for the belt - check the rest of my links on a bloody long (waaaay to long) story on my Airpump, which is undoubtedly cursed.

Maybe I should try exorcism!!! .

S'nut