Coolant Loss 1989
 

Changed water pump, Ford thermostat and radiator cap now I'm losing coolant. Pressure tested cooling system and found new cap was bad. While I had the system pressurized for about 2 hours I removed glow plugs and cranked engine to see if water blew out and it didn't. No oil in water and no water in oil / a puff of white smoke at start up and maybe a puff now and then under heavy acceleration. Replaced with a good cap and still having coolant loss of about 1/2 gal per day ( it only takes about 10 miles to do this). Truck has 240,000 or so miles and I have owned it since new. Used antifreeze additives once I heard of cavitation. Runs strong and uses very little oil. What do I check next?

check your overflow bottle. remove it an look it over good. the bottom of them can crack or wear threw, leaking the coolant out of the bottle when it gets warm.

Found it. Last night I cranked truck (dead cold) and started looking only to find radiator has hole which seemed to close up after about 5 minutes. Any recommendations on after market radiators?

rodney red. all aluminuim. custom made to fit. price isnt bad either.