On 26 May 2006 14:35:24 -0700, "
> wrote:

>i have a 1990, 300m with a very slight leak somewhere from the cooling
>system evidenced by a slow dripping of antifreeze from the botton of
>the radiator. i have pressure tested it and found no drop in pressure.
>when i run the motor with the pressure guage attatched the pressure
>rises very steadily - no spurts or jumps, and gets up to the "danger"
>mark on my pressure guage. it has a 16 psi cap. what is the operating
>pressure for the cooling system supposed to be? any ideas. ps. it was
>90 degrees when i tested it. thanks. brian


If you have a slow drip of antifreeze you need to trace the drip back
to its origin. Could be a leaking radiator or a leaking hose
connection..

Steve B.