My brother in law is having problems with his van,
so I'm posting for him.

Ok, here's the vital stats:
-86 Vanagon, fresh Boston Engine Rebuild just installed,
 initial run and break in done.
-The coolant system has been properly bled.
-Before the van comes up to temperature, pressure pushes
 coolant out up through overflow tank and out the pressure
 relief valve.
-overflow tank cap replaced, same problem.
-overflow tank and ajacent lines new prior to new engine (see below)
-radiator removed and dunk tank tested, no leaks found.
-Coolant system trace/dye tested, no leaks found.

Side note:
- this is similar to problem that occured before a new engine
  was needed. $600 worth of work was done to the coolant
  system, and less than 500 miles after a supposed fix,
  the original 77k mile engine threw a rod.
- The dealership replaced thermostat, and housing.

Any insight would be appreciated.

Thanks, Chris Binder
Milwaukee, WI