Keeping the engine cool isn't an easy job. Different parts of the cooling system have to work together to make sure that the engine will operate within an acceptable temperature range. Otherwise, it will overheat and may eventually seize up. To absorb heat, coolant circulates through the engine. This fluid is stored in an expansion or recovery tank also known as the coolant reservoir. When engine temperature has been stabilized, coolant from the reservoir is siphoned back to the radiator. And the cycle goes on and on.
As much as possible, you'd want the recovery tank and the rest of the cooling system to be in their best shape to perform a very crucial job. If there's any sign of damage or hint of trouble, you'd like to know what this could be so that you can prevent further damage. For the coolant reservoir, here are the common problems that you may have to deal with.
The reservoir overflows a lot. The coolant in the tank easily goes from full to below minimum level after the car has been driven.
This problem can very well be blamed on a faulty radiator cap. The cap may be letting out a lot of coolant. You have to check the cap to see if this is causing the overflow. To fix this cooling system glitch, the cap should be replaced. However, if the radiator cap seems to be working fine, you may want to see if you have a bad thermostat. This may also be caused by a damaged radiator or water pump. If you can't diagnose the problem, it's best if you let a professional take a good look and figure out the best solution.
After driving the car, the coolant stored in the coolant reservoir seems to be boiling.
It's not really a big problem if the coolant seems to be boiling. The vehicle's engine can get really hot, and as the coolant absorbs heat, its own temperature rises. The coolant usually boils when there's a lot of water in the system. The thermostat can be tested and replaced if necessary. The system needs to be flushed and topped off if the coolant boils and then evaporates. Make sure that you use the right type of coolant for the vehicle. If the radiator hoses are about to break, you may want to change these as well after getting the thermostat replaced and the system flushed and refilled with fresh coolant.
The coolant reservoir is empty.
If the reservoir is empty, the first thing you have to do is check for leaks. Do some pressure test to find where the leak is coming from, whether it's from the radiator or the hose. Check the tank for cracks as well. If everything checks out, see if the fan is actually working fine or turning too slow. A faulty temperature sending unit or loose connection may also have something to do with an empty coolant reservoir. You may check the thermostat as well. See to it that you bleed the system and refill it with fresh coolant.