My 1998 Chevy Crew Cab Dually, with 454 and auto transmission seems to be losing somecoolant into the overflow tank. The radiator level will be down and the overflow level will be up. I've also noticed while the truck was idling some fluid coming out from around the radiator cap. Also when I drained the oil last I had about 4 drops of water that seemed to come out.

I'm thinking probably a head gasket but the truck runs good and doesn't get hot. I pull a 40ft goosneck race trailer in the summer time and it always runs under 210 down the highway. When I stop and leave the AC on while it idles it sometimes wants to climb up a little but that may be normal.

What's your thoughts on this?

Thanks!!

 

my 2000 model 2500 series with 350 engine was doing the same thing.

Problem was the radiator cap, the gasket was bad on cap, got a new 16psi cap at auto parts store and in about 2 days the problem was solved. (Manual calls for a 15psi cap)

as motor cools down the vac is suspose to pull coolant back into radiator, if cap seal is bad, system will not work and leaves excess coolant in reservoir tank.

Hope this inexpensive fix works for you!!!!

 

if you got water out of the oil when you changed better take a close look at the head gaskets !you are building pressure .put a pressure tester on it ,you can check the cap with it also ,i believe stant and snap on makes them .