I'm planning to flush the cooling system of my 91 300TE 4M this weekend. As I am unsure of the length of duty the coolant has served I plan to use MB's lemon acid flush concentrate. The tech at MB said to pre-mix the entire bottle of granules (12oz.?) into a gallon of water and mix 1/2 the solution in the system (total cap. 9.5L) and run for 5 mins. at operating temp. Flush out with clean water and then mix the remaining half with water and repeat. After the last chemical flush run clear water through until no particulates appear.
Sound right? Should I put in the new thermostat first or should I complete flush sequence first? The old stat has failed "open".
Thanks in advance for your help.
Best

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Hazen Arnold
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