M11 Cummins

flatbedin · May 21, 2007

What would cause the coolant system to build pressure, and leak out of the overflow tube?

I had a oil analysis done the first of april, and no coolant was found in the oil.

The system has been flushed, heater core acid washed, new hoses put on. Radiator cap replaced, ect.

I also have a rig master unit on the truck, was wander if a broken fitting on the recirculation lines could cause a pressure build up?

highway star · May 21, 2007

Rig Master doesn't tie into the trucks cooling system.

flatbedin · May 21, 2007

Guess I need to figure out where these two coolant lines with shutoff going to the engine are used for then??

highway star · May 23, 2007

Did you follow those all the way to the engine, or could they be for the cooling/heating unit? The only place my unit ties into the truck is at the batteries. Everything else is independent.

flatbedin · May 23, 2007

No, I have two independent lines coming of a recircualtion pump on the back side of the unit. 1 going to the passenger side of the block with a shut off valve, and 1 going to the drivers side with a shut off valve.. My unit is a older unit, and I am guessing that they put a recirc pump on it to keep the engine block warm during cold winter starts.

That's just my guess. I have a copy of the schematic, and it's also showing two lines going to the engine block.