Possible blown head gasket.
There many other reasons for a vehicle to overheat besides thermostat and radiator cap. one example is retarded ignition timing.
You have to pull the lower radiator hose to drain/flush the radiator
Wong Nai Chung Reservoir Park was created in 1986.
It is under the chrome radiator cover.
The coolant capacity of a radiator in a 1986 Chevy Cavalier is 10.3 quarts. You can use any standard radiator fluid that's made for all makes and models of cars.
There is a drain plug just below the lower radiator hose.
lift it straight up
You can refill your 1986 Toyota Corolla power steering fluid through the power steering reservoir. The power steering reservoir will be on the left-hand side of the engine.
there should be a pitcock on bottom of radiator to drain it. or take the bottom radiator hose with motor cold of course .
It has a small radiator, upgrade it.
16 #
Remove cap to power steering reservoir, add fluid, place cap on reservoir when done.