GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value

Yes

No

1

Check the low side valve.

Is the low side valve closed?

--

Go to Step 2

Go to Step 3

2

Open the low side valve.

Is the valve open?

--

System OK

--

3

Check the pump oil.

Is the oil contaminated?

--

Go to Step 4

Go to Step 5

4

Change the oil. Refer to the manufacturer's instructions.

Is the oil change complete?

--

System OK

--

5

Check the charging lines.

Is a charging line loose?

--

Go to Step 6

Go to Step 7

6

Check the connections.

Are the lines properly connected?

--

System OK

--

7

Check the manifold.

Is the manifold leaking?

--

Go to Step 8

System OK

8

Check the connections.

Are the connections properly connected?

--

System OK

--