High Pressure/Temperature Water

This method uses common shop equipment and is relatively inexpensive. Turn-around time is short, and the actual process typically takes from 10-20 minutes. Use of this method is limited due to the rigid hose nozzles used. This method is effective when cleaning coolers with straight gas diffuser pipes (see Figure with respect to flow rate and flow volume. To be effective, the pressure washer must be directed first into one end of the cooler and then into the other to flush both directions. The high pressure/temperature water method is less effective on EGR coolers with bent or curved diffusers (see Figure because water cannot be forcefully directed into all of the internal tubes that require cleaning. This is also the case with coolers that have curved, wavy, or multiple internal passes for exhaust gas or internal chambers.

The following describes the cleaning procedure using high pressure (maximum pressure 3500 psi)/high temperature (maximum 160°C) water. Before proceeding, the cooler must be removed from the vehicle and all coolant and exhaust gas pipes removed from the cooler itself:

1. Suspend or strap the cooler vertically with the inlet end at the top. (See Fig 1
   Fig 1: Suspending Or Strapping Cooler Vertically With Inlet End At Top

   
2. Place a catch tray beneath the cooler to collect the resulting soot/water mixture exiting the cooler.
3. Clean the cooler from the inlet end first. Move the hose nozzle in varied directions as to channel the steam and water through as many passages as possible. Steam, water, and soot will flow from the outlet end of the cooler. Continue steam cleaning until the discharge water flowing from the cooler outlet is clear. (See Fig 2
   Fig 2: Cleaning Cooler From Inlet End

   
4. When the water coming from the cooler outlet is clear, turn the cooler over and suspend it from the outlet end. Clean the cooler through the outlet, and continue cleaning until the discharge water flowing from the cooler inlet is clear. The catch tray will need to be emptied into a larger container a number of times throughout the process.
5. Repeat Steps  , and  , several times. Altering the cooler orientation will help loosen stubborn deposits in the center of the cooler.
6. Hold the cooler vertically over a suitable catch pan with the cooler inlet end facing up, and then blow clean, dry compressed air into the inlet to remove water from inside the cooler. (See Fig 3 The cooler must be held vertically so that the water can flow out the lower end. Let the EGR cooler hang vertically until water has finished dripping; in some cases water will collect in the inlet or outlet diffusers. Repeat Step 5 as needed. It is important to drain all water to avoid engine damage when the cooler is reinstalled on the engine.
   Fig 3: Drying Compressed Air Into Inlet

   
7. Follow all applicable environmental laws regarding the disposal/treatment of the collected soot/water mixture.
8. Leak test the EGR cooler before engine reassembly.