Vacuum Pump: Service and Repair

Fig. 2 Gear driven vacuum pump. Chevrolet & GMC:

GEAR DRIVEN PUMP
Removal
1. Remove vacuum hose from vacuum pump inlet.
2. Remove bolt and clamp holding drive assembly to engine block, Fig. 2.
3. Carefully lift pump and drive assembly out of engine block.
4. Cover hole in engine block with cloth to prevent foreign matter from falling into engine block.



Installation
1. Remove protective cloth from engine.
2. Install pump and drive assembly in engine, ensuring gears on drive assembly mesh with gears on engine camshaft.
3. Rotate pump into position so bracket and bolt can be installed.
4. Install clamp and bolt, torquing bolt to 20 ft. lbs.
5. Connect vacuum hose to pump.

Fig. 3 Belt driven vacuum pump. Chevrolet & GMC:

BELT DRIVEN PUMP
Removal
1. Disconnect battery ground cable.
2. Disconnect vacuum hose.
3. Loosen and remove vacuum pump belt.
4. Remove vacuum pump pulley to hub attaching bolts, Fig. 3.
5. Remove pump and bracket from engine.
6. Remove bracket from pump. Hub must be pressed off vacuum pump and used on replacement unit.



Installation
1. Install bracket on pump.
2. Install pump and bracket on engine.
3. Install vacuum pump pulley and attaching bolts to hub.
4. Install vacuum pump belt and adjust belt to correct tension.
5. Connect vacuum hose to pump.
6. Connect battery ground cable.