This step is totally unnecessary.

Unless you plan on leaving the citric acid flush in the system, there’s no reason to neutralize it.

Once you’re done with the citric step, flush it all out a few times and you’re good to go.

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1981 240D 4sp manual. Ivory White.

Thanks for the input!
When you say 'flush it all out a few times', what exactly do you mean? TY

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1982 240d RHD OM605 & 5spd swap


1982 240D LHD/RHD & 300TD LHD / 1983 300SD LHD / 1986 300SDL LHD / 1992 300TD RHD / 1998 C250 TD RHD


www.repaircafeglasgow.org

Looking good there .

I have used a sheet of glass (think old window pane salvaged from the curb) and grinding compound to return those pesky alloy sealing surfaces back to perfectly flat .

Good on you for taking the time to address the details, I know few will bother to wash old hoses with soapy water, yes, it does make a difference, your engine is far gone so you must needs address the details diligently .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

I mean literally flush it out. Do you have a garden hose handy?
Same step as before the citric flush. Heater core, block, radiator, random hoses, get all the shiz out. Then, if you’re really particular (I have personally never taken this step as the water I’m using isn’t an issue) I suppose you could pour a few gallons of distilled water through to flush out the hose water.

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1981 240D 4sp manual. Ivory White.

What Shern said ! .

It's critical to flush and then reverse flush the heater core as it hangs down below the entrance nipples so sediment collects inside it and is near impossible to remove .

On your 240D or any gray market W123 without a Monovalve it's a very simple thing to undo the three (!) heater hoses and simply place the open end of your garden hose against one nipple have a helper turn on the water hard and watch the out flow ~ it'll typically run red / brown a moment then clear .

Reverse the flow by placing the hose to a different nipple and repeat, again you'll get a brief flow of cloudy water, then reverse the flow again, repeat until that short bust of cruddy water stops coming out, your heater will work better than ever before, even if you've deleted the electric auxiliary water pump and your engine will have more even cooling to boot .

Each time you reverse the water flow another layer of old rock hard dry silt comes off .

This is one more job where YOU will always do it better because you won't rush the job (or shouldn't), shops can't charge extra for this so they simply don't do a proper job .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better