coolant leak?

[twocamrys]

Six months ago, I was told that my coolant reservoir was empty when I went in for an oil change. The Toyota stealership said that my water pump was leaking from the weap hole and needed to be replaced. Since the water pump had just been replaced 20,000 miles prior, I took it back in to the independent shop that replaced it. They replaced the thermostat and gasket and claimed that the water pump itself was fine. Since that time, I have found that my reservoir has been a tiny bit low on two different occasions. I added some more fluid and have been keeping my eye on it.

Is it normal for a car to use a tiny bit of coolant over time? Or is this a sign that there may be a problem with my 2-year old water pump or some other part in the coolant system?

[JohnGD]

Was the coolant level stable for a while after the pump change, and then started going low fast? What can you tell about the leak (or no leak) at the weep hole?

Did the shop replace the thermostat 20K miles ago? If so and if they used an aftermarket one without a jiggle valve? If so and you saw large drops in the days after replacement then I'd suspect air in the system burping out.

Wait until the engine is cool, and open the radiator cap. What's the coolant level in there now?

If the rad is full when cold and the reservoir level drops gradually, then check for leaks. For example every gas up. Do you smell coolant in the engine bay, especially overnight?