w116 servo

[xaliscomex]

1979 300sd (w116)

Would a bad servo prevent the bleeding of all air from the cooling system.
I recently reported that my servo magically turned on after being dormant for a few years. Well its inoperable again.

My diesels temp gauge seems to be reading higher (hotter) than usual (195-205 deg F) when driving uphill or flooring the accelerator pedal on a flat stretch of highway, and this happened right after I replaced the coolant and thermostat. Not sure if I got all of the air out.

The temp gauge NEEDLE eventually does settle down to around 180-185 deg F when descending a hill or driving on a flat stretch of highway (the needle will sit right between the actual number 175).

I'm using the number 175 on my temp gauge as a reference to where the needle settles but keep in mind that the ACTUAL MARKING for 175 deg F is before you get to the number.

Not comfortable with this because I know from experience that my temp gauge is really sensitive and can register even the smallest coolant leak. I've looked around and haven't seen a drop of coolant. Will have to double check that.

I'm bleeding the air bubbles out by parking my car on an inclined driveway, removing the reservoir cap and running the engine for approximately 10 minutes. Since warm air is no longer coming out of the vents I feel that the coolant is not flowing thru the servo, thus preventing all of the air to be properly bled out.

Thinking about removing the servo and giving it a backwash to see what happens.

Replaced the fan clutch maybe 6 or 7 months ago
Using Zerex 05 concentrate and mixing it with distilled water (50/50).

Any advice on how to properly bleed the air out of the cooling system is greatly appreciated.