[Tf175]

I appreciate all the input , valuable advice and sharing of your experiences . I am moving at the speed of a glacier , but I have made some headway and want to report my findings thus far . 
Drained coolant , there was some black crud that came out initially , tablespoonful , max . 
We had topped off the radiator last year as the coolant level was about halfway in the sight glass , record shows approx 1 1/2 gallons to get to filler neck . Coolant used was from local truck shop , met all the Detroit requirements for two strokes , but it was red , I mixed with distilled water , 60% antifreeze. Existing coolant , green . Interestingly , the first to come out the drain was red , almost like the two types never mixed . Different specific gravity ? Coach had not been started for several days when drained . There is no sign of oil in the coolant. 18 gallons +- came out the drain , there must be other drains as I have read that the capacity is 27 gallons or so ? Radiator was not completely clean , especially in corners , but I could see through it . 
Removed radiator , unbolted top tank . Core looks new from the top . I intend to also remove bottom tank for cleaning . Using inspection camera through lower hose connection , bottom of core and flues look very good . There is a plate from Rawdon Radiator in S.D. , not sure when or what , but I think they must have serviced this radiator at some point for it to look this good . 
 As I mentioned before , one of the top hoses was kinked . After removing it I realized how bad the kink was , I deserve a demerit for not replacing it before now. 
 Once the rad was removed a new world opened up ! Now I could see the fan belts and they are Junk ! More demerits . Chunks are missing from the belts , they are cracked  and the sides of the vee are polished , obviously slipping . I doubt them making another 200 miles . 
 I am now curious about the inter/after coolers . Also interested in looking at the additional trans cooler mentioned . 
Much more work to do , just wanted to report my findings . 
Hope everyone is having a great summer out on the road !
Thanks, Chris

[Hotrodhornet]

I had a 81 Newell Classic with a 903 Cummins. Opening the louvers lowered the normal running temperature 10 degrees. 
My gauge was also reading high by about 10 degrees. I installed a mechanical gauge in the rear closet to compare the actual temp. with the front gauge.    
I now have a 1994 with a 8v92 . I am able to use the silverleaf monitor and never let the temperature go above 200.
I have the alarm set @ 196 and start backing off when it goes off. My biggest fear is overheating.
I also normally pull a 28 ft. enclosed trailer about 10,000 lbs   Paul

[77newell]

I believe any turbocharged two stroke Detroit engine has a built in aftercooler after the blower. It uses coolant to cool the compressed intake air. This, combined with the bottom end of the radiator providing cooling, or heating, to the transmission is a primary reason for the outsized radiators used with these engines, the heat load is ginormous.

I would also be cautious adding an additional transmission cooler if you plan to travel in cold weather. A primary reason for using the bottom reservoir of the radiator for managing the trans temp is that HT740 series Allison do not like cold fluid and in colder temps the fluid passing through the engine coolant helps get the tranny up to the desired temperature.

[[email protected]]

I am needing to replace the radiator in my 1986 8V92. Anyone have a good source out west? I live in Phoenix.

Going to comment on the misting system. Some previous owner installed one on my coach #121. As a result the radiator fins are all scaled up and unserviceable. Also, the core was not kept clean and the lower third of the core is filthy and plugged with road grime. Expensive result of a misting system fed by my fresh water tank.

[BusNit]

You can take it to Performance Radiator and have them build or rebuild your core. Also Serck radiator in Mesa can do it. Both are good shops. I've used both and found Serck to be a little slow in service but closer to my house.

[kyleb]

Whenever I notice my engine temps going higher than normal - the first thing I check is the fan belts. (When they are loose, I have heard them squeak while blipping the throttle in neutral.)
If they aren't tight, they won't spin the fan fast enough to push the required amount of air.

There is a reason there are 3 belts on the fan drive . . . . .

[Fulltiming]

Although it is more trouble in the short run, running from a small tank of distilled water exclusively for the radiator spray should avoid major problems further down the road. Sorry to hear it was plumbed into the fresh water tank.

[[email protected]]

Dropped my radiator off at Serck this afternoon. Thanks for the tip.

[BusNit]

Just be patient with them. They are slow to respond yet will get it done. I had a generator radiator modified of which they did a great job.