well when i drained my coolant from the engine block...i replaced back at least 2 gallons when filling up the engine core just right from the thermostat housing. this is excluding the radiator core...so thats about an additional gallon there...
Read my posts that i did for flushing: "got my parts---> doing the flush"
I posted this just about a couple of days ago.
performed the deoiling process and flushed until coolant is lighty green. Ran the super acid flush from prestone in the engine for about a good 3 days or 300-500 miles of driving; drained from engine block and ran water through there at least 3 times---> water sprayed all over the place when block plug is removed
refilled with clean water from the engine block...about 2 gallons of clean tap water with drain engine cock closed...
refilled the radiator with pure coolant and topped it off with water...please make sure that your thermostat vent bolt is off. When you do this, it is to prevent air pockets forming in the system. Also is a good idea to removed the thermostat while doing this so that the mixture of pure coolant in the radiator and the clean tap water in the engine and A/C parts are mixed well...even at low temperatures ( there wont be a thermostat blocking passage to the engine from the radiator via water pump). Once the radiator is topped off with water, close the vent valve on top of the thermostat and top off again with water in the radiator...
Close it all up and drive for a good 20 min to mix in; let cool and open vent valve on top of thermostat to ensure all air pockets are gone...close that up and top off with water in the radiator.
with this process you should get at least a 45/55 mixture of coolant to water ratio...if you desire..you can add water wetter to lower the operating temperature
with normal temps in the car..you should be generating a little less than 175F or 80C...with steep climbs like how it is here in colorado...you should max out at atleast between 80C and 100C....but never more than 100C---> note that this is with the thermostat off and A/C off in your diesel
IF PROBLEMS PERSIST:
If you are passing 100C or 212F in your car...you either need to removed your radiator and spray the heck out of it...removed the crudd from the radiator fins on the outside...
Or you have a leak somewhere in the car, replace radiator cap or renew your hoses and retighten them...maybe the belt on your water pump/alternator is slipping and not pumping water to the block...or your water pump needs to be changed out---like mine..because i'm loosing pressure at the gasket and i can see a coolant leak from there
all these possiblilities can drastically affect the performance of cooling on your car...
I hope this little tid bit will help ya'lls out on your journey of flushing these bad boys out...good luck and take carez
allen