Dear List Members,

Here's a coolant problem for you to ponder. Recently, on my 87 Westy, after being driven on the highway for an hour or more, the overflow tank gets completely filled. Sometimes, the coolant level is so high that coolant sprays from the vent hole on the top of the tank.

The tank slowly goes back to normal level if the van sits for a day or so, or if I let it idle for a while after the engine is cooled down.

While driving, the temp gauge is in its normal position. I've also bled the system a couple of times using a "bong".

Any ideas as to what could be causing this?

Thanks in advance.

Ric
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