LeSabre V6-231 3.8L VIN A 2-bbl (1984)
Vacuum Check Valve: Testing and Inspection
1.
Remove check valve from vacuum hoses.
2.
Connect a vacuum gauge to EFE side of check valve and connect a vacuum pump to other side of valve, then apply vacuum.
3.
The vacuum gauge should show a reading and hold that reading. If not, replace check valve. A slow leak-down indicates the check valve is
defective. If leak-down is fast, check to see if valve is backwards.