Volvo Coupes/Sedans/Wagons 1970-1989 Repair Guide

Vacuum Pump

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REMOVAL & INSTALLATION



Gasoline Engines

See Figure 1

  1. Disconnect the hose from the vacuum pump. Remove the four bolts and remove the pump from the engine.
  2.  
  3. Remove the upper cover, the seal, and the valve springs. Note and MARK the valve positions; they face in different directions in the cover. Remove the valves and the seals below them.
  4.  
  5. Matchmark the upper and lower halves of the pump assembly. This is essential for proper reassembly. A felt-tip marker works well. Remove the eight screws and separate the halves of the pump.
  6.  
  7. Remove the center screw, the washer, the diaphragm, the washers and the spring.
  8.  
  9. Remove the lower cover and the axle (pivot) pin for the pump arm. Place a shim such as a feeler gauge between the arm and the lever; this will prevent the arm from bending during removal of the pin.
  10.  
  11. Remove the pump rod and lever arm. Clean the parts and check them for damage. Pay close attention to the condition of the needle bearing for the pump arm.
  12.  
  13. To reassemble, fit the pump rod and lever arm into the housing and press in the axle pin. Use a shim to support the bracket while pressing the pin in. Put a drop of locking compound onto the ends of the pin to secure it.
  14.  
  15. Reinstall the bottom cover and seal.
  16.  



Click image to see an enlarged view

Fig. Fig. 1: Internal parts of the gasoline engine vacuum pump-be sure to install the washers correctly

  1. Assemble onto the center screw the washers, the diaphragm, the other washers and the spring. Make certain the washers are in the correct position.
  2.  
  3. Hold the pump upside down and fit the screw with the parts on it. Make sure everything lines up and seats properly.
    1. Reassemble the pump halves; use the matchmarks to position the halves.
    2.  

  4.  
  5. Install the seals.
  6.  
  7. Observe the marks made during removal and install the valves. Make sure they face in different directions.
  8.  
  9. Install the valve springs, the seal and the cover.
  10.  
  11. Use a new gasket and install the vacuum pump to the motor. Connect the vacuum hoses.
  12.  

Diesel Engines

See Figure 2

  1. Remove the hoses from the pump body. Remove the retaining bolts and lift the pump from the cylinder head. Remove the plunger from the cylinder head and thoroughly clean the pump.
  2.  
  3. Matchmark the pump body and the cover. This is essential to correct reassembly.
  4.  
  5. Remove the screws (1), the cover (2) and the gasket (3). Lift out the intermediate piece (11), the filler piece (10), both valves (12 and 13) and all three washers (14).
  6.  



Click image to see an enlarged view

Fig. Fig. 2: Exploded view of the diesel engine vacuum pump (and legend)

  1. Use a valve spring compressor tool (Volvo 6052 or similar) to press the diaphragm rod spring down about 0.4 in. (10mm). Unscrew the nut (4) while holding the hexagonal head of the rod stationary.
  2.  
  3. Release the compressor tool and remove the diaphragm rod (21), the washer (17), the O-ring (16) and the bushing (15).
  4.  
  5. Use the diaphragm rod to press out the plunger (6 or 6a) and the plunger disc (9). Remove the O-ring (7) and the piston ring (8). (6a is a one-piece plunger; it will not have an O-ring or piston ring.)
  6.  
  7. Clean all reusable parts and inspect for damage. The intermediate piece should be 0.59-0.60 in. (15.0-15.2mm) in height. The filler piece should be 1.02-1.03 in. (25.9-26.1mm) in height. Replace any worn or faulty parts.
  8.  
  9. Lubricate any new components with engine oil. Install the bushing (15), the O-ring (16) and the washer (17).
  10.  

9.Lubricate the diaphragm rod (21) and install it along with the spring plate (20), the spring (19) and the spring cup.

  1. Use the compressor tool and tension the spring so that the threaded end of the diaphragm rod extends about 0.2 in. (5mm) above the pump flange surface. Align the rod so that it is perpendicular to the flange.
  2.  
  3. Install the piston plate (9) on the diaphragm rod. Make sure the APG mark faces out.
  4.  
  5. Lightly lubricate the piston bore; insert the piston with its piston ring and O-ring (6,7, 8 or 6a) and be very careful not to damage the piston ring.
  6.  

On pumps with one-piece pistons (6a), insert the tapered end of the piston on top of the small washer (5).

  1. Install a new locknut (4) and washer (5) onto the end of the diaphragm rod.
  2.  
  3. Relieve the tension on the spring so that the bottom of the rod contacts the housing. Hold the rod stationary and tighten the locknut to 7 ft. lbs. (9.5 Nm)
  4.  
  5. In the pump body, install the three washers (14), the two valves (12 and 13), the intermediate piece (11) and the filler piece (10).
  6.  

After rebuilding the pump, the inlet valve is sealed by the large gasket (3), not by a separate smaller gasket.

  1. Install a new gasket (3) on the housing, install the cover (2) and tighten the screws in a diagonal pattern to 22-37 ft. lbs. (30-50 Nm).
  2.  
  3. Install the plunger and vacuum pump on the cylinder head. Tighten the mounting bolts and connect the vacuum hoses.
  4.  

 
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