GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value

Yes

No

1

Check for a leaking radiator.

Does the radiator leak?

103 kPa (15 psi)

Go to Step 2

Go to Step 3

2

Inspect the cooling system.

Is there still a loss of coolant?

--

Go to Step 3

System OK

3

Check for a leaking surge tank or hose.

Is there a leak in the reservoir or surge tank, or is the reservoir or surge tank hose damaged?

--

Go to Step 4

Go to Step 5

4

Replace the surge tank or hose.

Is there still a loss of coolant?

--

Go to Step 5

System OK

5

Check for any loose or damaged radiator hoses and connections.

Are any radiator hoses or hose connections damaged?

--

Go to Step 6

Go to Step 7

6

Reseat the hoses and clamps. If necessary, replace the hoses and the clamps.

Is there still a loss of coolant?

--

Go to Step 7

System OK

7

Check for a water pump gasket leak.

Is there a leak at the water pump gasket?

--

Go to Step 8

Go to Step 9

8

Replace the water pump gasket.

Is there still a loss of coolant?

--

Go to Step 9

System OK

9

Check for a water pump seal leak.

Is there a leak at the water pump seal?

--

Go to Step 10

Go to Step 11

10

Replace the water pump.

Is there still a loss of coolant?

--

Go to Step 11

System OK

11

Check the surge tank cap.

Is the surge tank cap damaged?

--

Go to Step 12

Go to Step 13

12

Replace the surge tank cap. Replace the tank if necessary.

Is there still a loss of coolant?

--

Go to Step 13

System OK

13

Check the cylinder head gasket for leaks.

Is the cylinder head gasket leaking?

--

Go to Step 14

Go to Step 15

14

Replace the cylinder head gasket. Refer to Cylinder Head Replacement in Engine Mechanical.

Is there still a loss of coolant?

--

Go to Step 15

System OK

15

Check if the cylinder head bolts are tightened to specification.

Refer to Fastener Tightening Specifications in Engine Mechanical.

Are the cylinder head bolts tightened to specifications?

--

Go to Step 17

Go to Step 16

16

Tighten the cylinder head bolts to specifications.

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