Truck kept running hot last weekend going over the Sierra passes. Checked
radiator and it's all clogged up with oil on the outside. I'm going to pull it out
and clean it , so I have a few questions.

1. My current coolant is GREEN , what type do I need to get from
the local auto parts store.

2. If I pull off the lower radiator hose will this drain the whole
engine and radiator ?

3. How do you collect all 4-5 gallons of coolant / water ?
In buckets ?

4. If I pull the thermostat , do I need a new gasket / o-ring ?

Thanks for the help.

 

1.any coolant is fine so long its aluminum compatiable (I prefer Amsoil, good for 500,000miles or 7yrs)
2. pulling the hose will get most all of it(out of engine) I believe the lower rad hose is 5-6inches from the bottom of the rad, so will have to drain rad after pulling it out, I find it better to pull the hose than muck with the drainvalve as most guys break them off, which results in needing a new rad.
3. if you get a large drain pan, you can direct the coolant by pulling the hose off slightly
4.do not remove thermostat (will cause nothing but heating cooling issues) replace it with a good thermo, OEM or Stant work well, they usually come with a rubber o-ring type gasket thats attached to the thermostat.

5. soak the rad externally with engine degreaser, and dont use more than carwash pressure to clean it out, some steam/pressure washers will bend the fins over if you hit it at the wrong angle, blow water from the clean side back thru the dirty side, otherwise you force the dirt in deeper.

mine took 10$ at a car wash before I had clean water pass thru it

 

OEM Cummins and NAPA stats are the only reliable ones have found. NAPA seems to have slight edge as does not seem to cycle as much. It cheaper also. In order to get all coolant from engine, remove the water pump. Get a new O ring for pump and stat. Can then rinse block with gardern hose. Green blood is correct stuff. Also use distilled water or pre mix as you desire. Tap water has minerals and clorine in, which kills inhibitors.
Many good suggestions above on cleaning, ect.

 

Cummins in house brand of coolant is blue...

I used a slightly different method to flush. I pulled out my thermostat, and then reversed the radiator top hose, so it would hang over the front of the truck to flow into a catch bucket. Then I directed a garden hose into the radiator filler, and ran the engine to fill the bucket. Clean water in and coolant water out. Took a few cycles to do it that way.

 

Post a picture of what yours looks like when your done. I did mine around two years ago and it made a big difference towing on hot days.
Amazing how much crud come out.
https://www.dieseltruckresource.com/...6&d=1217283623

 

If I pull my radiator , I assume the coolant will drain
from the engine block from the lower radiator hose.
Is there a way to refill the engine with coolant , or do
I have to remove the thermostat and fill through the
thermostat housing ?

 

the oil on the rad is caused by the crankcase vent catch bottle. you need to relocate it https://www.dieseltruckresource.com/...ugged+radiator

 

if you replace the thermostat, anyway, fill the coolant thru the thermostat hole until its flush with the top, insert thermostat,into the coolant, this ensures that there is no air under the thermostat, instal thermostat elbow and hose, finish filling rad,thru the rad. this should eliminate any chance of air lock