GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value

Yes

No

1

  1. Make a visual 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

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 surge tank.

Refer to Radiator Surge Tank Replacement

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

Reseat the clamps and hoses. Refer to the appropriate procedure from the following list:

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. Refer to Water Pump Replacement .

Is there still a loss of coolant?

--

Go to Step 11

System OK

11

Check for a water pump seal leak.

Is there a leak at the water pump seal?

--

Go to Step 12

Go to Step 13

12

Replace the water pump.Refer to Water Pump Replacement .

Is there still a loss of coolant?

--

Go to Step 13

System OK

13

Inspect the surge tank cap. Refer to Cooling System Leak Testing .

Is the surge tank cap damaged?

--

Go to Step 14

Go to Step 15

14

Replace the surge tank 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 Cylinder Head Replacement in Engine Mechanical.

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 Cylinder Head Replacement in Engine Mechanical. Refer to Cylinder Block Repair in Engine Mechanical.

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