seprice40

Well my truck seems to loose the antifreeze i put in the overflow but the radiator does not leak a drop (its been tested) so i know that its either the hose or my whole radiator overflow tank...but when i pour it in the antifreeze does not immediately leak out an then i will check it and some days it will leak and others it won't so I'm real confused.
Thanks in advance,
Steve

techrep

iTrader: (1)

I would replace the tank and hose...they get old and brittle and when hot can leak.

dirtcrew51m

Your radiator cap might b bad and pushing the antifreeze out when the engine gets up to temp, besides a new cap is alot cheaper than a reservoir.

94Bronc

when the engine gets hot, the coolant expands into the "overflow"(aka expansion) tank. when the engine cools back down, it sucks the coolant back in. did you test the system or a mechanic? was it pressure tested? at what temperature?

seprice40

well the radiator was really not pressure tested but it always seems to be full even if my overflow is bone dry when the engine is cool and warm.

94Bronc

if theres an internal leak(burning off the coolant instead of leaking on the driveway) when the system gets low it will pull from the overflow tank, so maybe when ever the tank is empty your catching it just after it has. is there any difference or pattern with when the tank goes dry? like longer drives, or out side temps. could be a slow headgasket leak or similar i'd try a pressure test and see if it holds pressure

seprice40

Ok sounds like pressure testing is in order for the spring but the radiator has never been low and it just seems it will randomly leak and other days it wont some times weeks or months at a time it wont leak than it will.
thanks for your help
p.s. this is my daily driver and it s a 4.9l 300 '94 f150 XL