I thought I'd throw this up here for posterity.
B6000's don't have a water pump and rely on the thermosiphon principle for cooling. After a while they'll push coolant out and overheat.
After forty years of refilling the radiator and overheats, the fix is incredibly simple once I thought through the dynamics of the water flow. The problem is the radiator cap and that it creates a pressurized system with no way to reclaim the coolant that has been pushed out from expansion. Every time it heats up a little coolant is pushed out the radiator overflow tube.
Take the cap off and drill a few holes in the bottom part of it with the rubber seal that seals into the radiator neck to create pressure. Or, completely remove it and the spring leaving only the large diameter seal that seats against the top of the radiator neck.
You must add an expansion tank like is used in automotive applications. I got one at NAPA for $8. Take the overflow hose and run it to the bottom of the new tank. Fill the tank and you're good to go.
Since I did this about five years ago it runs at 180-190F on the hottest days.
B6000's don't have a water pump and rely on the thermosiphon principle for cooling. After a while they'll push coolant out and overheat.
After forty years of refilling the radiator and overheats, the fix is incredibly simple once I thought through the dynamics of the water flow. The problem is the radiator cap and that it creates a pressurized system with no way to reclaim the coolant that has been pushed out from expansion. Every time it heats up a little coolant is pushed out the radiator overflow tube.
Take the cap off and drill a few holes in the bottom part of it with the rubber seal that seals into the radiator neck to create pressure. Or, completely remove it and the spring leaving only the large diameter seal that seats against the top of the radiator neck.
You must add an expansion tank like is used in automotive applications. I got one at NAPA for $8. Take the overflow hose and run it to the bottom of the new tank. Fill the tank and you're good to go.
Since I did this about five years ago it runs at 180-190F on the hottest days.