i have a 85 yamaha tri z and when the engine warms up, the coolant will go into the resevoir like it is supposed to but when the engine cools down the coolant isn't being syphoned back into the radiator. why is it doing this? do i have a bad radiator cap and if so are there any other tests to perform on it to make sure that is the culprit before spending $30 for a new one. thanks for the help.
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When the engine warms up you should only lose coolant into the overflow if it is overheating. Your dealer should have a rad cap tester and be able to perform this test while you wait.