What should the pressure be on a brazed radiator?
These caps can only be used with quality brazed radiators vs. the OEM ones that are sealed with epoxy. These drawings show how radiator caps work in releasing the pressure, and how they allow the water to return to the radiator when it cools down. Generally, 25-psi is the maximum pressure quality radiator caps are rated for.
What are the benefits of increasing radiator pressure?
The increase in pressure in the cooling system is where the cooling benefits emerge. In the heads principally, the pressure reduces small air pockets and it reduces the onset of nucleate boiling and preignition.
Why is the radiator cap on the low pressure side?
The crossflow design can allow the radiator cap to be positioned on the low-pressure (suction) side of the system, which prevents the pressure created by a high-flow water pump from forcing coolant past the radiator cap at high rpm. Open radiators with a cap need a recovery tank to receive the excess coolant that has passed through the cap.
How does a double pass radiator increase coolant speed?
Passing the coolant through one-half of the radiator twice doubles the coolant speed and its pressure. However, since a double pass radiator reduces the volume of water that passes through the core in half, its pressure also doubles.
What causes coolant to overflow from the radiator?
As coolant gets hot due to it absorbing heat from the engine, the liquid expands and creates additional pressure in the radiator. As the pressure causes the coolant to get higher than the radiator pressure cap, the excess coolant needs to be captured somewhere in order to prevent leakage.
When to flush the radiator and cooling system?
The fix: When flushing the radiator and cooling system, make sure you run the engine with the pressure cap off for 15 minutes after refilling the system. This will bleed any air from the radiator and cooling system before you replace the pressure cap. Read our comprehensive guide on how to do a coolant flush.
The increase in pressure in the cooling system is where the cooling benefits emerge. In the heads principally, the pressure reduces small air pockets and it reduces the onset of nucleate boiling and preignition.
These caps can only be used with quality brazed radiators vs. the OEM ones that are sealed with epoxy. These drawings show how radiator caps work in releasing the pressure, and how they allow the water to return to the radiator when it cools down. Generally, 25-psi is the maximum pressure quality radiator caps are rated for.