GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Inspect for a leaking radiator.

Is the radiator leaking?

Go to Step 2

Go to Step 3

2

Repair or install new parts as necessary.

Is the repair complete?

System OK

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3

Inspect for a leaking heater core.

Is the heater core leaking?

Go to Step 2

Go to Step 4

4

Inspect for a faulty radiator pressure cap.

Is the radiator pressure cap operating properly?

Go to Step 5

Go to Step 2

5

Inspect for a leaking coolant recovery tank.

Is the coolant recovery tank leaking?

Go to Step 2

Go to Step 6

6

Inspect for any loose or damaged hoses.

Are any hoses damaged or leaking?

Go to Step 2

Go to Step 7

7

Inspect for leaking water outlet.

Is the water outlet leaking?

Go to Step 2

Go to Step 8

8

Inspect for a leaking water pump.

Is the water pump leaking ?

Go to Step 2

Go to Step 9

9

Replace the water pump. Refer to Water Pump Replacement .

Is the repair complete?

System OK

Go to Step 10

10

Inspect for a leaking engine block coolant drain plug.

Are any drain plugs leaking?

Go to Step 2

Go to Step 11

11

Inspect for any leaking cylinder head core plugs.

Are the cylinder head core plugs leaking?

Go to Step 2

Go to Step 12

12

Inspect for a leaking cylinder head gaskets, or a cracked cylinder head.

Are the cylinder head gaskets leaking or is the cylinder head cracked?

Go to Step 2

Go to Step 13

13

Inspect for a leaking throttle body.

Is the throttle body leaking?

Go to Step 2

Go to Step 14

14

Inspect for a cracked cylinder block.

Is the cylinder block cracked?

Go to Step 2

Go to Step 15

15

Inspect for porosity leaks.

Are the castings OK?

System OK

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