Have them perform a pressure test on the cooling system. If there is pressure loss you have a problem somewhere.

 

It's simple, keep a eye on your coolant tank to make sure it don't get low in the reservoir. It's located near the windshield water fill neck. I traded my '07 TCH so I can't remember but I think their is a line on the coolant tank showing the approximate level.

A toyota tech when I ask him, told me to use a rather bright flashlight at night and look around the water pump drive pulley by looking over the passenger side fender. It's located close to the air conditioner compressor with the two large orange cables coming out of it.

Another when leaning over the passenger side fender your looking at the front of the engine. Best I can remember the right most pulley should be the water pump.

Look for any red power residue (dry or wet spot) on the water pump pulley itself, the shaft or the belt.

If your coolant tank don't need any red toyota coolant added then you should be ok. Mine had not leaked the 5 years I owned it although the toyota tech did add maybe 3 inches of coolant when I dropped by for a liquid check before having them appraise my car for the trade.

Some have mentioned using a different brand replacement water pump other than the toyota brand which may fail again. I have heard NAPA being used and Georgia Hybrid found a foreign made pump replacement that he likes.
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As long as you keep checking the coolant level and keep it topped off, I doubt that you will have any engine damage from the leaking seal. The exception to that is possibly some electrical sensor or part shorting out if the leak gets very bad. Either way, you will be replacing the water pump sooner or later and to be honest about it, I didn't even notice mine was leaking and was very surprised at the amount of residue inside the pulley.

Your tech can pressure check the system but the leak is so slight, it will take a while for it to show up. On the other hand, if he nervous about working on a hybrid, share the water pump replacement link with him and you might set him at ease.

 

I have a '09 TCH which is 4 1/2 years old with 52k miles on it. Thanks to this forum's chatter about water pump problems and watching for overflow tank levels I had Toyota replace it under the power train warranty.
I noticed the coolant overflow tank had gone down a little so I had the Toyota dealer check the water pump out when it was in for the power window switch recall. The service writer made me agree to a $50 coolant system check before they would touch it but they found it was leaking and replaced it for free.
That was the good part - then they tried to sell me on draining and refilling the eCVT tranny for $240 plus replacing both air filters for $90. Deep inside I was laughing when I politely declined the additional $340 for the service I could perform for well under $100.
A good policy to keep in mind when dealing with a service writer is "JUST SAY NO" then go to a trusted mechanic for a second opinion.

 

Good call! Draining and filling the Trans-axle is literally as easy as doing an engine oil change. $90 for air filter replacement?! Whew...

I guess I got lucky... My first water pump made it to 114,000 miles and I now have over 41,000 miles on the replacement @ 155,500 miles.

 

Thank you UWAdventurer, rburt07, and GeorgiaHybrid for your advice on my supposed coolant leak. Even two weeks after my post, my coolant is well above the low level mark on the coolant tank. I looked using rburt07's descriptions to see if I could see any red or pink residue inside the engine compartment, but still found nothing. If there is a leak, I think it is minor. I'm going to check every few weeks to see if the coolant level drops. The distance between the full and low marks on the coolant tank is about 4 inches and it is about 0.75 inch below full now. If the coolant level starts dropping more, I'll have the pressure test UWAdventurer and GeorgiaHybrid mentioned done. Thanks again for your help.