Just make sure that the thermostat is positioned with the V or the pointed part of the thermostat is pointing downwards.
Just remember that even though that the coolant reservoir is close to full but when you start the engine and the thermostat opens up, it fills up all part of the cooling system and so your coolant reservoir gets low.
I don't like the coolant reservoir cap because it is threaded type. The radiator does not have a cap.
Typical radiator has a radiator cap which is easy to remove by pushing and rotating the radiator cap and coolant reservoir cap does not have to be tightened good.
On our 1994 Pontiac Grand Am 2.3L, I have to use a strap wrench
http://www.sears.com/sr/javasr/produ...000&adCell=P11 or similar wrench to tighten it or loosen it. If you don't tighten the coolant reservoir cap, air is introduced and guess what? Coolant starts boiling (gurgling sound) when a hot coolant is exposed to air.
Remember the coolant reservoir is like part of the radiator and has to be completely close and so the coolant reservoir cap needs to be tightened up good.