Component Tests and General Diagnostics

Vacuum Pump Hose Assembly:

Vacuum Pump Grommet:

NOISE DIAGNOSIS

Excessive pump noise may be caused by grounding of the pump or the pump lines. The pump mounting and lines should be inspected prior to replacing the pump for a noise complaint. Check the three vacuum pump mounting screws, they should be perpendicular to the vacuum pump mounting bracket. If the screws are cocked they will prestress the rubber grommets which isolate normal pump noise and vibration from the bracket. It may be necessary to align the rear leg of the bracket by hand to allow the mounting screw to be installed perpendicular between the pump and bracket. Make sure the three rubber grommets are installed as shown.

Vacuum Pump Altitude Specifications:

PERFORMANCE CHECK

The electric vacuum pump may be checked for proper operation using the following two bench tests.
1. A vacuum gauge attached to the intake side of the pump should register approximately 21 inches Hg after 10 seconds of pump operation with the outlet side vented to atmosphere.
2. With the electric vacuum pump operating with a blocked intake and exhausting to atmosphere the current draw at 13.5 volts should not exceed 8.0 amps.
The electric vacuum is not serviceable and should be replaced if diagnosed and found defective.