Leaking coolant reservoir

[Ado Sigal]

The quickest way to find what is at fault, is to pressurize the system 
and the cap. Within minutes you'll know exactly/

Ado

Kent McLean wrote:

>I had a slow coolant leak on my '94 100S V6 that over the past few
>months has gotten not-so-slow -- the coolant reservoir (overflow
>tank) will drain over the course of 7-10 days.
>
>David Torrey suggested checking the heater control valve beneath
>the windshield wiper linkage.  Before I got under the plastic
>"water deflector" (that's what ETKA calls it) at the base of the
>windshield, I saw wet below the coolant reservoir. A swipe of a
>finger and a sniff told me it was coolant. Doh!
>
>I removed the reservoir and was surprised to see there were no
>cracks in the tank. The hoses seem OK. (Why do the hoses have to
>have different diameters at each end? Morons.) I thought the sensor
>may be the culprit, but sucking on it seemed show it to be sealed.
>It is a slow leak, so I wouldn't expect it to be like sucking on
>a straw, but I didn't feel any seepage.
>
>Is the reservoir under the same pressure as the rest of the cooling
>system?  Might my sucking (I'll ignore any comments directed that
>way) not be enough to show a leak at the sensor?
>
>For now I'm going to put it all back together and hope it was just
>a loose connection at a hose.
>
>  
>