Hyundai Repair: Hydai trajet, coolant leaks, upper radiator hose

Question
Hi, I have a hyundai trajet mpv. It has a slow water leak which both my mechanic and myself can't find. Any suggestions of what common problems could be causing this. Thankyou

Answer
First, you'll need to investigate whether you're being misled into thinking you have a leak.  The answers the following will help determing whether you have a leak.

1.  How much coolant is lost over what period of time?
2.  Is the coolant level in the radiator full?
3.  How low does the coolant get in the reservoir?

If the radiator isn't full, normal continued operation will continue sucking coolant out of the reservoir until the radiator is full.  If the reservoir is overfilled, it can overflow when the engine reaches operating temperature.  Additionally, there is a very small amount of evaporation of coolant in the reservoir as well.

I don't have any particular knowledge of the trajet, since it's not available in the U.S., but the 2.0 and 2.7 are at least similar to engines used in the U.S.  Often, small coolant leaks occur at the upper radiator hose fitting to the engine, or at the water pump seal.  In some cases, the leaks are so small as to only leave a white trail where the coolant has run.  

Water pump leaks on the 2.0 are typically visible by inspecting the neck of the water pump with a mirror.  The water pump on the 2.7 is completely covered.  There is a weep-hole exit approximately behind the A/C compressor mounting.  If you see white crust or coolant there, it's an indication that your water pump is leaking.