why not just use detergent then copious amounts of water?  Personally, i
  would not put citric acid followed by a buffer in my coolant system.
W/o a pH meter you'll never know if you put in too much 'buffer' to
neutralize the citric acid.
-matthew
chemist

Doktor Tim wrote:

> At 01:48 PM 11/04/2003, you wrote:
>
>> Hi all,
>>
>> Does anyone have a recommendation for how to clean out the
>> cooling system on an '84 Westy while the engine is out being
>> rebuilt?
>
>
> Mecedes calls for use of dilute citric acid to remove oil deposits from
> cooling systems for their diesels. It requires follow up with a buffering
> solution and thorough rinsing. It says repeat if necessary. This is a
> procedure that will insure results. Like so many such procedures, it is
> much easier to say than to do properly.
>