GM/Detroit 6.5L – COOLANT PUMP REPLACEMENT

GASOLINE ENGINES
Remove or Disconnect (Figures 23, 24, and 25)
1. Coolant from the radiator.
2. Upper fan shroud. Refer to SECTION 6B2.

3. Drive belt Refer to “ Drive Belt Replacement.”
4. Fan, fan clutch, and pulley from the coolant pump.
Refer to “ Fan and Fan Clutch Replacement.”
5. Lower radiator (outlet) hose and heater hose from the coolant pump.
• On the 7.4L engine, remove the bypass hose.
6 . Bolts.
7. Coolant pump from the engine block.

Clean
Mating surfaces on the coolant pump and the engine block.

Install or Connect (Figures 23, 24, and 25)
1. Coolant pump to the engine block.
2. New gaskets.
3. Bolts.

Tighten
• Bolts to 41 N.m (30 Ibs. ft.).
4. Lower radiator (outlet) hose and heater hose to the coolant pump.
• Bypass hose on the 7.4L engine.
5. Coolant pump pulley, fan, and fan clutch to the coolant pump hub. Refer to “Fan and Fan Clutch Replacement.”
6. Drive belt. Refer to “Drive Belt Replacement.”
7. Upper fan shroud. Refer to SECTION 6B2.
8. Start the engine and run, with the radiator cap removed, until the upper radiator hose becomes hot (thermostat is open).
9. Add coolant to the radiator until the level reaches th e bottom of the filler neck.
• Engine must be running at idle speed.
10. Radiator cap, making sure the arrows line up with the overflow tube.
11. Check for leaks.

DIESEL ENGINES
Remove or Disconneot (Figure 26)
1. Negative battery cable. Refer to SECTION OA.
2. Coolant from the radiator.
3. Fan shroud. Refer to SECTION 6 B 2 .
4. Fan. Refer to “Fan and Fan Clutch Replacement.”
5. Drive belt. Refer to “Drive Belt Replacement.”
6. Raise vehicle. Support with safety stands.
7. Vacuum pump mounting bracket nuts.
8. Bolt holding vacuum pump bracket and generator.
9. Vacuum pump with bracket.
10. Power steering pump lay aside. Refer to SECTION 3B1.
11. Power steering pump mounting bracket. Refer to SECTION 3B1.
• Lower vehicle.
12. Lower radiator hose from pump.
13. Bypass hose from pump.

14. Bo l ts (90, 92, and 96), studs (93 and 97), coolant pump plate (99), and the coolant pump (91) (figure
26).
15. Bo lt (98) from the rear of the coo l ant pump plate.
16. Coolant pump (91) and gasket (94) from the plate (99).

Clean
• All flanges must be free of oil. Clean the mating surfaces on the coolant pump, both sides of the
coolant pump plate, and the engine block.

Install or Connect (Figure 26)
1 . Gasket (94).
2. Coolant pump (91) to the coolant pump plate (99).
3. Bolt (98).
• Bolt (98) to 23 N.m (17 Ibs. ft.).
4. Coolant pump (91) and coolant pump plate (99) to the engine.
• Apply anaerobic sealer (GM P/N 1052357).
• The sealer must be wet to the touch when the bolts are tightened.
5. Bolts (90, 92, and 96) and studs (93 and 97).
Bolts (90 and 96) and studs (97) to 23 N-m (17 Ibs. ft.).
Bolts (92) and studs (93) to 42 N.m (31 Ibs. ft.).

6. Bypass hose and lower radiator hose.
• Raise vehicle. Support with safety stands.
7. Power steering bracket and pump. Refer to SEC­TION 3B1.
8. Vacuum pump and bracket.
9. Bolt holding vacuum pump and generator. Refer to SECTION 6H.
• Lower vehicle.
10. Fan and pulley. Refer to “Fan Clutch Replace­ment.”
11. Drive belt. Refer to “Drive Belt Replacement.”
12. Fan shroud. Refer to SECTION 6B2.
13. Negative battery cable.
14. Coolant in the radiator or surge tank. Refer to “Draining and Filling the Cooling System.”
15. Radiator or surge tank cap, making sure the arrows line up with the overflow tube.
16. Check for leaks.