Cadillac Repair: overheating 89 coupe Deville, radiator pressure tester, head gasket problems

Question
I pressure tested the system and it held at 16
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I recently asked about my caddy over heating. Sometimes i get heat and then i dont. i just replaced the radiator and its fluid. there are no leaks in the hoses or the water pump and i got the air out. It just over flows the resivor.
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You need to test for head gasket problems via a radiator pressure tester.

Answer
Are the cooling fan or fans working properly ?.

Could be a radiator restriction.

With the age and mileage on the vehicle, I would replace the radiator with a NEW radiator.

Do NOT get your old one CLEANED and or REPAIRED. Buy a NEW one and replace the thermostat.