I put a new water pump and hoses on my 300D. I have 2.5 gallons of coolant in it and the temp gauge was running high, a little over 100°C, so I shut it down. I tried parking it on a steep hill to get the coolant in but I believe I may have an air pocket preventing circulation. Is there a way to purge the air from the system? I had it running with the cap placed but not screwed down.

Yep, common problem. Put car (front end) on ramps. Fill from the coolant hose coming off block using a funnel -remember to have heater levers on so heater core fills as well. Some folks here like to fill by loosening upper radiator hose and filling this way but I find hose off block even better -good luck!

don't forget to open the bleeder on the thermostat housing...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I remove the hose from the right rear side of the block? Mine is A 1978, does it have the bleeder?

I filled the upper radiator hose and removed the bleeder screw. It still ran hot. I filled the thermostat housing by means of the bleeder hole and still runs hot. I replaced the thermostat and the same. The upper radiator hose has hot water in it and the top of the radiator is hot. The lower radiator hose is cold and the heater lines are cold. I have almost 3 gallons of coolant in it. I tried parking on a steep hill too. I will try filling the rear block hose next.

I removed the rear block hose and filled the block, with the bleeder screw removed, until coolant came out of the bleeder hole. It took about 3/4 gallon after I had filled everything else with cooolant. Now it is cooling properly.