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What type valve that is clear are you talking about?


I use one similar to this to shut off to block flow in summer mounted on firewall connection:
http://www.amazon.com/Four-Seasons-84707-Shut-Off-Valve/dp/B000DCNGLK#productDetails

The one review that says it leaks through the thread is not very accurate. When the valve is fully off or on it does not leak. Only weeps a little fluid when opening/closing.

92 Montero LS 3.0L V6 Auto, Stock, Original owner, 185,800K miles