Difference Vented Non Vented Radiator Cap

And thus normally closed.

Difference vented non vented radiator cap.

As i understand a vented cap or closed system cap means as the system cools down it will pull fluid from the zero pressure recovery tank. Vented were used on older models without an overflow recovery tank. The cap will not allow air or coolant to expand out of the radiator until the design pressure is met 7 or 13 lbs depending on model. This goes over the differences between a vented and a non vented radiator cap.

Explains the difference between vented and non vented caps with recommendations for coolant recovery applications. A non vented cap will not allow pressure to enter the system. With the tank you re venting at the recovery tank far enough away from the radiator to not loose coolant in the process. 93 96 16 psi vented cap 97 98 18 psi non vented cap zj v8.

So if it s vented it will allow coolant to drain from the high points i e. If you do not then it will create a vacuum inside of the radiator as it cools. You ll end up with a big air bubble in the engine and an overflowing overflow tank. Open means when the pressure gets too high it releases onto the ground.

The top of the engine into the overflow tank. 91 92 13 psi non vented cap 93 95 16 psi vented cap 96 06 18 psi non vented cap zj 4 0. Non vented was used on newer models with the recovery tank. Now let s look at a vented cap.

This means that if you remove the cap and allow the pressure to be released then you must wait until it has cooled back down before putting the cap back on. The radiator cap needs to be non vented. This cap will have 2 rubber seals o o a non vented cap or open system cap means it will not pull fluid back into the cooling system. Xj that i noticed.

This is the cap that actually goes on the radiator. 99 02 20 psi non vented 03 04 18 psi non vented this would explain the difference between the pressure in the zj vs. The radiator cap is not the highest point in the cooling system. Closed meaning fluid is not released to the ground via an overflow tube.