Alan,
Spin the pump shaft clockwise while listening for unusual bearing noises. You should hear some noise from the vanes in the pump. The same noise should change pitch/tone when spinning the pump backward. If you hear the rollers in the bearings, either change the bearings or the pump.
If the noise is not excessive, cover the pump outlet with one hand while spinning the shaft/pulley. There should be a slight pressure. The pump does not create any high pressure or flow, so moving air is about as good as it gets, and is all that is required.
Personally, if I had a pump that failed I'd be tempted to install an electric air pump from an LT1 and only run it at startup. This would involve a little wiring with a temperature switch, but would allow the pump to be installed in a remote location and eliminate the clutter under the hood. If that is not plausable, a replacement pump is the next best bet.
Eliminating the pump might not be an option in your area, and doing so would only create a little more space and free up about 1-2HP at peak engine RPM.
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Later,
Vader
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