The EGR cooler is a common source of coolant leaks. This hose connects the coolant flange on the cylinder head directly to the heater core.
While the hose can be clamped directly to the heater core, we recommend purchasing the straight-end coolant coupling (available) to replace the angled connector to the heater core.
Finally, two small coolant overflow lines must be joined using a barb fitting, also available.