Coolant Filter Install on M939A2

Hey Gang,

I want to install a coolant filter kit on my 8.3CTA Cummins. I have flushed it out numerous times with water, but it still has a nice rusty tint to it. I have switched to 50/50 since the temps have been dipping down towards freezing.

Since it has a fuel-burning heater kit installed, I plan on using the hot water heater hookups. My question is, which do I use for the inlet and outlet on the 8.3?

Also, I was thinking about using some clear hoses to hook it up at first so I can see how clean the water-coolant mix is getting. I will switch to regular heater hose before any road use. Anyone see a problem with that? It's rated for 60 psi at 80* or something.

I think I will pull the thermostat too for the time being. That way it will circulate all through the radiator and clean out as much crud as possible. If I had to bet, I would say my new thermostat already has a lot of sludge on it.

Any bets on how quickly the coolant filter will plug up? I figure I will take an extra just in case. That would be another good reason to use the clear hose at first I guess.

Comments? Thoughts?

Chris, for how long did you flush it? Did you follow the procedure? You should be able to get a clear flow from flushing one time, just keep it going and you can do the radiator separately.

The coolant filter is in a bypass loop, so it will take a while for all fluid to pass just one time...

The direction of flow is from the outside of the filter to its center and it should generally flow from the top of the engine through the filter and then to the water pump, where ever the ports are on that Cummins.

Edit: The flushing should be in reverse (opposite normal flow).

Bjorn, since the truck is in the middle of a field, it had to be flushed without the benefit of a hose. I had to use 1 gallon and 5 gallon containers full of water. That was inadequate to say the least. It will be a while before I can drive it to a location with a continuous water supply so I am trying to clean it up the best I can right now.

So the highest port on the engine should provide the input to the filter and the lowest one closer to the water pump should receive the output from the filter, correct?

Yes, that's right.

You can also flush by repeatedly filling the coolant system and using compressed air at some low pressure, say 10 psi, to force the water out.