MBE 900 – Section 6.4 Turbocharger

Section 6.4
Turbocharger

An exhaust gas turbocharger is standard equipment on all MBE 900 engines. To determine if the turbocharger needs to be replaced, do a visual inspection and then inspect the control unit.‪

Section 6.4.1
Inspection

Inspect as follows:‪

1. Inspect the air induction system for loose connections. Check the ducts and lines for cracks, punctures, or corrosion.
2. Disconnect the exhaust ducting from the turbo compressor outlet and check the turbocharger wheel for damage.

   Note: A light may be useful for examining the turbocharger wheel blade tips inside the turbocharger housing. The surfaces requiring inspection can be viewed from the outlet of the turbocharger housing.

3. If the turbocharger wheel rubs against the housing, or if the blades are damaged, replace the turbocharger (refer to "6.4.2 Turbocharger Removal" ).
4. Disconnect the air duct from the compressor air inlet and check the compressor wheel for damage. If the wheel is damaged, or if the wheel rubs against the housing, replace the turbocharger (refer to "6.4.2 Turbocharger Removal" ).
5. Inspect the entire turbocharger system for excessive oil.

   Note: A light film of oil is normal in the air inlet compressor area and exhaust ducting.

6. Check the oil supply and return lines for leaks. Tighten all connections to the proper torque value.
7. Install the air inlet and exhaust ducts, then tighten all connections.
8. Check the outside of the control unit for abnormal conditions. If the unit is damaged, replace the turbocharger. Refer to "6.4.2 Turbocharger Removal" .
9. Disconnect the hose from the control unit. See Figure "Testing the Control Unit" .
   

   1. Control Unit‪	3. Hose‪
   2. Hand Pump‪

   Figure 1. Testing the Control Unit

10. Attach a hand pump and pressurize it to 100 kPa (14.5 psi).
11. Check for air leaking from the diaphragm between the valve rod and the control unit housing. If air is leaking at this location, replace the turbocharger. Refer to "6.4.2 Turbocharger Removal" .

Section 6.4.2
Turbocharger Removal

Remove the turbocharger as follows:‪

PERSONAL INJURY ‪
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

1. Apply the parking brakes, shut down the engine, and chock the tires. Raise the hood.
2. Disconnect the air cleaner pipe from the turbocharger and the air filter housing
3. Disconnect the turbo compressor outlet pipe from the housing. See Figure "Turbocharger Removal" .
   

   1. Turbo Compressor Outlet Pipe‪	6. Oil Return Line‪
   2. Oil Supply Line‪	7. Oil Return Hose‪
   3. Turbocharger‪	8. Exhaust Brake Valve Housing‪
   4. Heat Shield‪	9. Exhaust Brake Air Line‪
   5. Seal Gasket‪	10. Exhaust Pipe‪

   Figure 2. Turbocharger Removal

4. Disconnect the exhaust brake air line.
5. Disconnect the exhaust pipe at the exhaust brake valve.
6. Disconnect the oil supply line from the turbocharger and the rear of the oil filter housing.
7. Disconnect the oil return line from the turbocharger and discard gasket.
8. Remove the nuts that attach the turbocharger to the exhaust manifold. Remove the turbocharger and exhaust brake valve housing.
9. Remove the heat shield from the turbocharger and exhaust brake valve housing.
10. Remove the fasteners that connect the exhaust brake valve housing to the turbocharger.

Section 6.4.2.1
Checking Radial and Axial Play

Check as follows:‪

1. Check radial play.
   1. Rotate the shaft assembly by hand while applying equal side pressure to the compressor and turbocharger wheels. Neither wheel should rub against the housing.
   2. If there is contact with either side of the housing, replace the turbocharger.
2. Check axial play.
   1. Rotate the shaft assembly while pushing it in one direction, then the opposite direction. Neither wheel should rub against the housing.
   2. If there is contact with either side of the housing, replace the turbocharger.

Section 6.4.3
Turbocharger Installation

Install the turbocharger as follows:‪

Note: The torque values are listed in Table "Torque Values" .

1. Inspect the air cleaner pipe, turbo compressor outlet pipe, exhaust manifold, and the oil supply and return lines for restrictions or foreign objects.
2. Install the turbocharger on the exhaust manifold. Use new nuts to install the turbocharger. Tighten the nuts. Use the torque values listed in Table "Torque Values" .

   Description‪	Part‪	Torque Values‪
   Turbocharger to Exhaust Manifold Nuts‪	4–Cylinder Engine‪	30 N·m (22 lb·ft)‪
   	6–Cylinder Engine‪	50 N·m (37 lb·ft)‪
   Exhaust Brake Valve‪	M8 Fastener‪	30 N·m (22 lb·ft)‪
   	M10 Fastener‪	50 N·m (37 lb·ft)‪
   Turbocharger Oil Supply Line Bolts‪	M6 Fastener‪	10 N·m (7 lb·ft)‪
   	M8 Fastener‪	40 N·m (30 lb·ft)‪

   Table 4. Torque Values
3. Using new nuts, install the exhaust brake valve housing on the turbocharger. Tighten the nuts.
4. Attach the heat shield to the turbocharger and the exhaust brake valve housing.
5. Using a new gasket, attach the oil return line to the turbocharger.
6. Fill the bearing housing with clean engine oil through the oil inlet port. Turn the turbocharger wheel several times to coat the bearings with oil.

   Note: If the turbocharger wheel cannot be spun freely by hand or if there is any indication of rubbing or scraping, determine if the contact is due to wheel rubbing resulting from a misaligned turbocharger housing or foreign object in the wheel area.

7. Refill the oil inlet port and connect the oil supply line. Use the torque values listed in Table "Torque Values" .
8. Connect the pipe between the exhaust brake valve housing and the exhaust pipe.
9. Connect the exhaust brake air line.
10. Attach the turbo compressor outlet pipe to the turbocharger. Tighten the clamp firmly.
11. Attach the air cleaner pipe to the turbocharger.

    PERSONAL INJURY ‪
    To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

    PERSONAL INJURY ‪
    Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.‪ Always start and operate an engine in a well ventilated area. If operating an engine in an enclosed area, vent the exhaust to the outside. Do not modify or tamper with the exhaust system or emission control system.

12. Start the engine and allow it to run at idle speed for three to four minutes before accelerating.
13. Check for oil leaks and correct accordingly.