Low oil causing the coolant to heat up to the point in which it's doing more harm than good so it's pushed into the overflow
The radiator cap could be the cause of coolant reservoir overflow or backup. Have the cap checked to see if it is bad.
Overfilling a coolant reservoir.......isn't possible since they have an overflow line.... Water is cycled back and forth as needed... with movement of water, air in the top of the reservoir is obviously necessary, since overfilling the reservoir would cause the overall cooling system to fail to do its' job!....... In otherwords, If you try to overfill the coolant reservoir tank, it shoud automatically start draining the excess water/coolant onto the ground. The other reason for the overflow is to protect from high pressure in times of high temperatures..... steam and water can both escape this way. Chris... c-tekk@hotmail.com
coolant fan
Coolant is used to keep an engine in a vehicle at a temperature safe for operation. If no coolant is in the reservoir, an engine will not start.
This is a indication of a blown head gasket,unless it has been over filled or overheated.If you are getting combustion in the cooling system you will see air coming up through the coolant in the reservoir,be careful it can blow hot coolant out without any warning.Most shops have a tool that will detect combustion gases in the coolant,it should be a inexpensive test.
broken radiator
If the brake fluid reservoir is overfilled, the excess fluid runs through the overflow instead of over the bodywork, which would cause damage to the paint work.
you have to find where the leak is first.
When changed air was introduced to the system theres two little nozzles you have to open up and turn your car on to release the air. Let it go till coolant is constantly squirting out of both of those holes then while its still squirting out close them problem solved. It is also possible that the reservoir was too full to begin with. Most coolant reservoirs have a minimum and maximum fluid level which should be maintained. Too much fluid will cause overflow and too little fluid can cause the radiator to operate at less then 100% efficiency.
There are a couple of things that can cause oil to get into your coolant reservoir. A blown head gasket or a broken piston ring are the most common causes.
Either coolant is low or the sensor in the reservoir is stuck with dirt. Clean the reservoir with soap and water
In the engine compartment on the drivers side towards the back of the car there is an overflow reservoir. The reservoir is a sphere, off-white in color and has a 3" diameter black cap that screws on. The cap made to loosen by hand, but usually takes a lot of strength and grunting to remove.WARNING! Do not remove the cap if the engine is warm, hot coolant may spray out and cause severe burns!There are coolant level marks printed on the side of the reservoir. Because of the age of the plastic reservoir, it is no longer transparent. This means the coolant level cannot be checked without removing the cap an looking inside.