GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1997 🢒 GMC K Pickup - 4WD 🢒 Engine 🢒 Engine Cooling 🢒 Loss of Coolant

Step

Action

Value

Yes

No

1
  1. Make a visual check of the cooling system.
  2. Check the ground under the vehicle.

Is there coolant visible on the ground?

--

Go to Step 3

Go to Step 2

2

Inspect the cooling system for proper pressure retention.

Does the cooling system maintain the correct pressure?

--

Go to Step 13

Go to Step 3

3

Check for a leaking radiator.

Does the radiator leak?

--

Go to Step 4

Go to Step 5

4

Repair or replace the radiator. Refer to Radiator Replacement .

Is there still a loss of coolant?

--

Go to Step 5

System OK

5

Check for a leaking coolant recovery reservoir or surge tank.

Is there a leak in the reservoir or surge tank?

--

Go to Step 6

Go to Step 7

6

Replace the coolant recovery reservoir or surge tank.

  1. For gasoline engine, refer to Coolant Recovery Reservoir Replacement .
  2. For diesel engines, refer to Surge Tank (Diesel) .

Is there still a loss of coolant?

--

Go to Step 7

System OK

7

Check for any loose or damaged radiator hoses or connections.

Are any radiator hoses or hose connections damaged?

--

Go to Step 8

Go to Step 9

8
  1. Reseat the clamps and hoses.
  2. If necessary replace the hoses and the clamps.
    • For the 4.3L and 5.0L engines, refer to Radiator Hose Replacement .
    • For the 5.7L engine, refer to Radiator Hose Replacement .
    • For the 7.4L engine, refer to Radiator Hose Replacement .
    • For the 6.5L engine, refer to Radiator Hose Replacement .

Is there still a loss of coolant?

--

Go to Step 9

System OK

9

Check for a water pump gasket leak.

Is there a leak at the water pump gasket?

--

Go to Step 10

Go to Step 11

10

Replace the water pump gasket.

    • For gasoline engines, refer to Coolant Pump Replacement .
    • For the diesel engine, refer to Coolant Pump Replacement .

Is there still a loss of coolant?

--

Go to Step 11

System OK

11

Check for a water pump seal leal.

Is there a leak at the water pump seal?

--

Go to Step 12

Go to Step 13

12

Replace the water pump.

    • For gasoline engines, refer to Coolant Pump Replacement .
    • For the diesel engine, refer to Coolant Pump Replacement .

Is there still a loss of coolant?

--

Go to Step 13

System OK

13

Check the radiator filler cap.

Is the radiator filler cap damaged?

--

Go to Step 14

Go to Step 15

14

Replace the radiator filler cap.

Is there still a loss of coolant?

--

Go to Step 15

System OK

15

Check cylinder head gasket for leaks.

Is the cylinder head gasket leaking?

--

Go to Step 16

Go to Step 16

16

Replace the cylinder head gasket. Refer to the appropriate procedure:

    •  Cylinder Head Replacement in Engine Mechanical - 4.3L
    •  Cylinder Head Replacement in Engine Mechanical - 5.0L, 5.7L
    •  Cylinder Head Replacement in Engine Mechanical - 6.5L
    •  Cylinder Head Replacement in Engine Mechanical - 7.4L

Is there still a loss of coolant?

--

Go to Step 17

System OK

17

Inspect the cylinder head and cylinder block.

Is the cylinder head or cylinder block cracked?

--

Go to Step 18

Go to Step 19

18

Replace or resurface the cylinder head or cylinder block as necessary. Refer to the appropriate procedure:

    •  Cylinder Boring and Honing in Engine Mechanical - 4.3L
    •  Cylinder Boring and Honing in Engine Mechanical - 5.0L and 5.7L
    •  Cylinder Boring and Honing in Engine Mechanical - 6.5L
    •  Cylinder Boring and Honing in Engine Mechanical - 7.4L
    •  Cylinder Head Replacement in Engine Mechanical - 4.3L
    •  Cylinder Head Replacement in Engine Mechanical - 5.0L and 5.7L
    •  Cylinder Head Replacement in Engine Mechanical - 6.5L
    •  Cylinder Head Replacement in Engine Mechanical - 7.4L

Is there still a loss of coolant?

--

Go to Step 19

System OK

19

Check for a leaking heater core.

Is the heater core leaking?

--

Go to Step 20

System OK

20

Make the necessary repairs or replace the components as necessary in order to repair the leak.

Is there still a loss of coolant?

--

--

System OK