I had a 20 year old Sears air compressor that was a Speedair compressor with a Sears name on it. About every 3 years I replaced the reed valves in it. It was a cheap repair job. I replaced the motor once because flood waters ruined the original motor. I was surprised how much bigger the GE 3 HP motor was compared to the Sears motor. It had an eye-hook for lifting it with a crane!
About 18 months ago, the plastic hub of one of the wheels on the old compressor broke, tilting the air pump, and causing it to seize up because the oil was no longer where it was supposed to be. That drove me to upgrade to Sears' "professional" Model 919.165600, 6.5 HP (heavy duty?) oil-less compressor with a 60 gallon tank. I thought it might be easy to maintain and hoped it would be more reliable by virtue of its "professional" label. It rarely got used, but was always on. It probably turned on and refilled the tank once a day when I wasn't using it. It wasn't what I would call professional duty.
One day, upon returning from work, I heard it running, but sounding strange. Both connecting rods had broken, and it wasn't pumping air. The loose rods destroyed the cylinders by beating them badly. I figure the first broken rod took out both cylinders, then the second rod broke. They also shattered the end of the motor that supported the pump. The cost of parts alone to repair it added up to $350.00. The whole thing cost $430.00 new these days!
It was pretty obvious that the days of $10 repairs were over. It is pretty clear that critical parts that should have been steel were just aluminum, and weren't up to the job. I will never own an oil-less compressor again. The repairs are simply too expensive due to the catastrophic nature of the failures. You can see the results if you like by clicking the images below:
Well, I'm not into repeating expensive mistakes. Instead, I took my old GE 3 Hp motor (much larger than Sears' liberally rated 6.5 Hp motor) and constructed a compressor platform of my own design. I used the Sears 60 gallon vertical tank, and nothing else from that unit. A new frame for a larger motor/pump platform on top of the origonal motor/pump mount on the tank was the first addition. I didn't want to disturb the tank itself by welding on it.
The platform for the motor and compressor head is mounted to the frame through vibration isolators with a clevis pin through the mounts. No metal parts can cause any rattling from the vibration because they don't touch anything else made of metal. Finally, instead of messing with belt adjustments I added a 50's vintage Chevy truck belt tensioner. Two flat vertical bars support a belt guard.