Thin oil zone below a gas cap
Oil
The radiator does not have a cap, instead, the coolant system reservoir is also pressurized and the pressure cap is on the reservoir.
The primary reservoir drive mechanisms are (1) Gas drive which includes both solution gas drive as well as gas cap drive (2)Water drive (3) Gravity drainage and (4) Combination drive.
The thread on cap on the coolant reservoir is the " radiator " cap
The thread on cap on your engine coolant reservoir is your pressure cap / radiator cap
The thread on cap on the engine coolant reservoir is the pressure cap / radiator cap
The thread on cap on your engine coolant reservoir is your pressure cap / radiator cap
On a 2003 Ford Thunderbird : The thread on cap on your engine coolant reservoir is the pressure cap / radiator cap The engine coolant reservoir is in the engine compartment , on the drivers side of the engine compartment , near the firewall . You can see the cap on the reservoir through a hole in the " trim "
The thread on cap for your engine coolant reservoir is the pressure cap / radiator cap ( the engine coolant reservoir is located on the drivers side of the engine compartment , near the firewall )
A hot radiator releases excess coolant through the spring-loaded cap in to the reservoir, and when cooled the partial vacuum created by cooled radiator pulls it back in. A reservoir should be only about 1/4 full cold on a system that uses a radiator cap, some cars have a pressurized cap on reservoir and no cap on radiator
In petroleum engineering, an oil rim field is an oil field with a relatively thin oil zone below a gas cap. At the edges of the reservoir there will ususally be an area where the top of the reservoir is below the gas/oil contact, thus forming a "rim" containing only oil, with no overlying gas.