This is a procedure I used when we had a 99 Monaco Diplomat with good results.
I tried a new way to clean my radiator A while back and it really got a lot of black gunk out. First let me say that
I have cleaned the radiator 2 to 3 times a year for the past 4 years. I used a 2 gallon garden sprayer the type with the wand and
fill with 1 gal of Simple Green, on the 99 dip I can raise the bed to get to the radiator, I first sprayed with water ( be careful not to
wet down the alternator) then soaked it real good with Simple Green, about a quart. Closed the engine cover, cranked the engine, opened the
engine cover and sprayed about another 2 qts of soap in the fan be careful with the wand dont get it in the fan, I dont think this would
need to be done every time), closed the engine hatch and run the engine up to about 1500 a couple times to get the soap thru the
radiator. I then shut the engine down and let it soak for 30 minutes. Washed the radiator with water restarted the engine and
washed with water some more, close the hatch run the engine up to about 1500, I did this a couple times. Shut the engine down and washed
from the rear. I was surprised at the black gunk that was between the CAC and Radiator. After testing I found that this method dropped my
Trans temp by about 10 deg in city driving and in hilly country on those +90 deg days according to the VMSpc program that I run on my laptop.
I did not use a pressure washer (but I think you could with the gentle nozzle), I used the regular water pressure 50# with my hose and spray nozzle.
Note be sure to rinse good to remove all simple green from the alum CAC and radiator.
Walt N Will
F191141