Does the cap for the radiator resevoir tank have a small pin hole for excess fluids too leak?
No. It is designed to prevent any coolant to drain out on ground.
No... but your water pump has whats called a "Weep Hole" which allows small amounts of fluids to drain out. If you are seeing coolant puddle below your vehicle, you have a problem.
If you have a leak, visit your local auto parts store and ask for the loaner tool to check for a coolant leak. The tool will screw on top of the reservoir tank. Pump it up to about 12 lbs on the gauge (no more). If there is a leak somewhere, believe me, it will be easy to see.
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