I have a 1988 Pickup 3.0L 4X4 5 Speed, that sit in a barn for about 5 years. I have been working on it for about a year off and on, it runs perfect now but now when it gets warm it is starting to leak radiator fluid. It will leak out about a half gallon in about 10 minutes if your running it hard. I can not see exactly where its coming from, it comes down by the transmisson.

Anyone have any tips of where to start looking at?

 

It is not leaking anywhere around the radiator, it is up underneath the motor somewhere.