GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Inspect the radiator.

Is the radiator leaking?

Go to Step 2

Go to Step 3

2

Repair the radiator as necessary.

Is a loss of coolant still evident?

Go to Step 3

System OK

3

Inspect the surge tank cap.

Is the surge tank cap faulty?

Go to Step 4

Go to Step 5

4

  1. Perform a surge tank cap pressure test.
  2. Replace the cap if necessary.

Is a loss of coolant still evident?

Go to Step 5

System OK

5

Inspect the following components:

    • The coolant surge tank
    • The hoses

Is the surge tank or the hoses leaking?

Go to Step 6

Go to Step 7

6

Replace the surge tank or the hoses.

Is a loss of coolant still evident?

Go to Step 7

System OK

7

Inspect the following components:

    • The radiator
    • The heater hoses
    • The connections

Is any damage evident?

Go to Step 8

Go to Step 9

8

Repair or replace the components as necessary in order to correct the leak.

Is a loss of coolant still evident?

Go to Step 9

System OK

9

Inspect the water pump seal.

Is the water pump seal leaking?

Go to Step 10

Go to Step 11

10

Replace the water pump.

Is a loss of coolant still evident?

Go to Step 11

System OK

11

Inspect the water pump sealing surface.

Is the water pump O-Ring or gaskets leaking?

Go to Step 12

Go to Step 13

12

Replace the O-Ring or gaskets.

Is a loss of coolant still evident?

--

System OK

13

Inspect the cylinder block, cylinder head and gasket surface.

Is the cylinder block, cylinder head or gasket leaking?

Go to Step 14

System OK

14

Repair or replace the components as necessary in order to correct the leak.

Is a loss of coolant still evident?

--

System OK