Just got a Mityvac. Want, among other things, to replace my coolant with it. I've never replaced my coolant (i.e. I've had it done for me), but want to add this to the short list of things I'm able to do.

I'm confused by the instructions. They say: "Select the largest diameter dipstick tube and insert the tube into the radiator neck or expansion tank." Full instructions here http://mityvac.com/user_manuals/07201.pdf.

So, since I have an expansion tank, does this mean that I draw all the coolant that I'm able to extract through the expansion tank? And I assume without initially removing the cap from the radiator...or would that matter? And then, once I get all the coolant out, I fill both the radiator and the expansion tank, or do I just fill through expansion tank? It doesn't make sense to me that I'd be able to get the coolant out through the expansion tank.

Thanks for your patience with very basic questions....I have aboslutely no idea what I'm doing but it seems like something I ought to be able to do pretty easily.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 159k miles
06 E320 CDI "Rutherford", Black on Tan, 178k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 145k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 75k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife