Hi! I'm new to this site, i just picked up a 1988 Toyota cargo van wagon 2WD automatic. I bought it from a guy on the west coast of Florida who was the original owner since '88. I've noticed a slight overheating problem though, any advice is greatly appreciated:
When i drive it for about 15 mins or more, my temp gauge goes up to 50% and hovers between there and 75% for the remainder of my driving, never goes into the red zone though. I've pulled over a number of times, and checked my radiator and overflow reservoir, and both are full! The overflow reservoir usually boils though. However if i wait for about 5 minutes, I've noticed that water comes pouring out of my reservoir-bleeder hose, it gushes out quite rapidly (out of the end, not a leak in the hose). I'm 17 years old and I really dont have a lot of money to be throwing around into this van, so I'd like to source the problem and be done with it. I've replaced the Radiator Cap already, and I was thinking of replacing the Thermostat. Any ideas? Anybody else have this problem with their van?

Thank you in advance!
-Elliot