EGR Cooler Leak Tester for VAG Vehicles

The EGR cooler leak tester exposes the EGR system and exhaust circuit to controlled overpressure for accurate leak detection. A high-sensitivity pressure gauge connected to the expansion tank monitors the system: even a small pressure rise (>0.02 bar) signals a potential fault.

Working Method:

1. Ensure coolant temperature ≥ 40°C.

2. Open the expansion tank and connect the test adapter to the pressure gauge hose.

3. Lift the vehicle and disconnect the exhaust system at the mid-section.

4. Connect silicone hoses, pressure adapter, and hose clamps.

5. Set the pressure regulator to minimum and unlock the rotary knob.

6. Connect the lever plug nipple to the adapter and pressure regulator.

7. Connect the workshop air hose.

8. Open the regulator slowly to reach the vehicle-specific maximum pressure.

9. Maintain pressure for at least 5 minutes, monitoring the gauge.

10. Even small pressure changes indicate a defective component.

Advantages:

• Fast and accurate EGR cooler leak detection

• Detects even minor leaks in the cooling system

• Adjustable pressure regulator for safe testing

• Includes high-sensitivity pressure gauge and silicone hoses

• Compatible with VAG vehicles and many others

OE numbers are for reference only; this is not an original tool.

This EGR cooler leak tester is designed for identifying slow or hidden coolant leaks, primarily on VAG models (VW, Audi, Seat, Skoda), but it can also be used on other vehicles. Undetected coolant loss may indicate a defective EGR cooler or cylinder head.

Information:
The tester pressurizes the exhaust system and the EGR cooler circuit (exhaust side) with a preset overpressure for an extended period. Any resulting pressure escape into the coolant system is measured with a sensitive manometer attached to the coolant reservoir. Even a small pressure increase (>0.02 bar) indicates a leak in the EGR cooler.

Procedure:

1. Ensure coolant temperature is at least 40°C.

2. Open the expansion tank and connect the correct test adapter to the manometer hose via the quick coupling.

3. Lift the vehicle and disconnect the exhaust system at the mid-section pipe connector.

4. Slide the appropriate silicone hose onto the pipe, insert the adapter, and secure with hose clamps.

5. Set the pressure regulator to minimum (turning out = closed) and unlock the knob upward.

6. Connect the lever nipple to the adapter and pressure regulator.

7. Connect your workshop compressed air hose to the pressure regulator.

8. Slowly open the pressure regulator until the maximum vehicle-specific pressure is reached (e.g., 2.0 TDI Audi A3 CRBC = 0.5 bar, Polo 6R 1.6 TDI CAYB = 0.8 bar – follow manufacturer specifications).

9. Adjust the pressure if necessary until the system is filled. Ensure maximum pressure is not exceeded.

10. Maintain the system under pressure for at least 5 minutes and monitor the manometer. Any slight pressure increase (>0.02 bar) indicates a defective EGR cooler. Minor pressure drops due to cooling can be ignored.