If you remove your radiator cap while cold, should the coolant be up to the top of the radiator, or does coolant flow from the radiator to the reservoir before cooling down?

 

Yes, the radiator should be full when cold.

 

It is a closed system and the radiator should be full to the top when cold. If needed, the system will send coolant to the remote reservoir when hot and pull it back into the radiator when it cools down.

 

I just don't understand why when I remove the radiator cap the level is a bit low, yet there is still coolant in the resevoir

 

Perhaps your cap is bad. It won't work if it is (or if there is a leak in the system the bleeds off pressure prematurely).

 

I just replaced the water pump, so perhaps the system still has some air in it. I also have a new cap on order. Will install and post results.

 

I have a very old leak that has stained the side of the radiator and had problem with the coolant doing what your saying. I haven't seen any leaks after i replaced the cap. I figured the plastic side of the radiator had a crack or hole but its never wet so it must have fixed it.

 

Something as simple as a crack in the overflow hose from the radiator neck to the reservoir will prevent the system from pulling the coolant back from the reservoir to the radiator when the radiator cools down.

 

I've also seen cars that hadn't used the overflow tank in a while (because the owner had a leak and kept pouring water in) and the hose to the tank was clogged with crap - outside chance I know, but something else to check

 

Just to close this up...I got a new radiator cap from Cromer and now when I remove the radiator cap, the coolant is to the top of the radiator.

On a side note, the cap says "align the arrows with the overflow tank tube and one arrow says "TVS" and the other arrow says "RC94".Does it matter which one is pointed at the overflow tube?