Re: Chevy Trans cooler Install
JSG,
A really easy way to tell which line is which is to remove BOTH lines from the radiator, stick a long hose on each one and lead the hoses into a drain pan. Have a buddy start the engine, or start the engine yourself and use your cat like reflexes to quick run and look which hose fluid is comming out of and quick run back and shut her down. Now you'll know which hose goes "into" the radiator.
Depending on how quick you are you'll only lose a quart, maybe two of fluid, it comes out at a good flow but it won't shoot out or spray all over the place.
Don't worry, you wont ruin anything doing this.
Heck, while your at it, run the engine with the hoses diconnected until the tranny oil flow just starts to taper off, shut her down, refill, do this about 3 times and you just flushed out your tranny and you'll have fresh fluid.