Series 638 – Section 6.4 Air Gas Recirculator Valve

Section 6.4
Air Gas Recirculator Valve

The air gas recirculator valve AGR reduces the intake manifold pressure to improve fuel economy and reduce emissions. See Figure "Air Gas Recirculator Valve Parts Location" .‪

1.Air Gas Recirculator Valve Adaptor‪	6.Intake Manifold Elbow‪
2.Gasket‪	7.Washer‪
3.Air Gas Recirculator Valve‪	8.Allen Head Screw‪
4.Torx Screw‪	9.Nut‪
5.Gasket‪	10.Stud‪

Figure 1. Air Gas Recirculator Valve Parts Location

Section 6.4.1
Replacement of Air Gas Recirculator Valve

To determine if replacement of the air gas recirculator is necessary perform, the following procedure. See Figure "Flowchart for Replacement of Air Gas Recirculator Valve" .‪

Figure 2. Flowchart for Replacement of Air Gas Recirculator Valve

Section 6.4.2
Removal of Air Gas Recirculator Valve

Remove the air gas recirculator valve as follows:‪

1. Disconnect the AGR valve vacuum hose.
2. Remove the AGR bleed line.
3. Remove two mounting nuts. See Figure "Removal of Air Gas Recirculator Valve" .
   

   1.Air Gas Recirculator Valve Adaptor‪	6.Intake Manifold Elbow‪
   2.Gasket‪	7.Washer‪
   3.Air Gas Recirculator Valve‪	8.Allen Head Screw‪
   4.Torx Screw‪	9.Nut‪
   5.Gasket‪	10.Stud‪

   Figure 3. Removal of Air Gas Recirculator Valve

4. Remove the AGR valve and gasket from the intake manifold elbow. See Figure "Removal of Air Gas Recirculator Valve" .

Section 6.4.3
Cleaning of Air Gas Recirculator Valve

Clean the air gas recirculator valve as follows:‪

1. Remove all old gasket material from the AGR valve and the intake manifold elbow mating surfaces.
2. Clean the AGR valve and related parts with clean fuel oil.

   To avoid personal injury when blow drying, wear adequate eye protection (safety glasses or face plate) and do not exceed 276 kPa (40 lb/in. 2 ) air pressure.‪

3. Dry the AGR valve and related parts with compressed air.

Section 6.4.3.1
Inspection of Air Gas Recirculator

Inspect the air gas recirculator valve as follows:‪

1. Visually check the AGR valve gasket surface area for nicks.
   1. If the AGR valve gasket surface area is nicked, repair as necessary. Refer to "6.4.3.2 Testing of Air Gas Recirculator Valve" .
   2. If the AGR valve gasket surface area is not nicked, proceed with step 2 of inspection.
2. Visually check the AGR valve gasket surface area for burrs.
   1. If the AGR valve gasket surface area is burred, repair as necessary. Refer to "6.4.3.2 Testing of Air Gas Recirculator Valve" .
   2. If the AGR valve gasket surface area is not burred, proceed with step 3 of inspection.
3. Visually check the AGR valve gasket surface area for scratches.
   1. If the AGR valve gasket surface area is scratched, repair as necessary. Refer to "6.4.3.2 Testing of Air Gas Recirculator Valve" .
   2. If the AGR valve gasket surface area is not scratched, reuse the component. Refer to "6.4.3.2 Testing of Air Gas Recirculator Valve" .

Section 6.4.3.2
Testing of Air Gas Recirculator Valve

Test the air gas recirculator as follows:‪

1. Connect an air supply line to the AGR valve vacuum port.
2. Visually observe that the AGR valve opens when air is applied.
   1. If the AGR valve did not open, replace the component. Refer to "6.4.4 Installation of Air Gas Recirculator Valve" .
   2. If the AGR valve did open, reuse the component. Refer to "6.4.4 Installation of Air Gas Recirculator Valve" .

Section 6.4.4
Installation of Air Gas Recirculator Valve

Install the air gas recirculator as follows:‪

1. Install the AGR valve with a new gasket to the intake manifold. See Figure "Installation of Air Gas Recirculator Valve" .
   

   1.Air Gas Recirculator Valve Adaptor‪	6.Intake Manifold Elbow‪
   2.Gasket‪	7.Washer‪
   3.Air Gas Recirculator Valve‪	8.Allen Head Screw‪
   4.Torx Screw‪	9.Nut‪
   5.Gasket‪	10.Stud‪

   Figure 4. Installation of Air Gas Recirculator Valve

2. Install two mounting nuts to secure the AGR valve to the intake manifold. Torque nuts to 23-25 N · m (17-18 lb · ft).
3. Install the AGR bleed line.
4. Connect the AGR valve vacuum hose.
5. Run the engine to verify repair.