thermostat or air in clling system replace thermostat and bleed the system
Yes. First top up the radiator then fill the overflow reservoir to the "HOT" mark if the engine is hot or the "COLD" mark if the engine is cold. Be CAREFUL when you remove the radiator cap on a hot engine. The coolant is under pressure.....
Do it when the car is cold if the radiator is hot fluid may be forced out when you take off the cap.
A radiator cap can not only be hot, but it is holding in pressure. When the cap comes off under pressure, hot antifreeze will spray out, possibly causing injury.
The radiator cap may not be getting hot because it is located in a separate reservoir from the radiator itself. It is designed to maintain pressure within the cooling system and does not directly contact the hot engine coolant.
Remove the radiator cap when the engine is cool and add the coolant into the radiator or you can add to the coolant overflow bottle. DON'T remove the radiator cap when the engine is hot!!!
On most cars if they don't have a radiator cap, then you can put it in the cooling system by pouring it in through the upper radiator hose. Even if you are suppose to do this while engine is hot DO NOT because it will have the same affect as pulling the radiator cap while hot.
wait for the engine to cool
Hot water in the radiator is under pressure and can burn you.
A radiator cap should never be opened when the engine is warm or especially hot!The specific steps for your vehicle type may then instruct you to start the car with the cap off and run the engine while filling, but never open the radiator when hot.Reason: the cooling system builds up pressure as the engine warms, and removing the cap while pressurized will create a dangerous geyser of coolant.
If the engine is cold... it could mean that the radiator cap is too weak to hold and you need to get a new one. If the engine is HOT... it could mean that you have overheated it and you need to add water after the engine has cooled a bit, to prevent getting burned, be careful and use a towel to remove the cap to add coolant.
Open the radiator cap when the engine is cool, check the radiator's fluid level, and add appropriately. NEVER OPEN A RADIATOR CAP WHEN THE ENGINE IS HOT OR OVERHEATING. Check your car's owner's manual for specific details.
It could be that the radiator cap is not able to maintain pressure. Check the radiator cap for cracks or any other damage. Replace if necessary. DO NOT remove the radiator cap when the engine is hot.