Universal vacuum pump apparatus and method

An apparatus for use with brake systems of a tow vehicle and a trailer towed by the tow vehicle, the tow vehicle brake system generating a brake fluid control signal based on a driver's operation of the tow vehicle brake system, the apparatus comprising:

• a control valve coupled to receive the brake fluid control signal and coupled to the trailer brake system, the control valve generating a vacuum control signal to control the trailer brake system, based on the brake fluid control signal;
• a vacuum sensor coupled to sense a vacuum supply used to generate the vacuum control signal, the vacuum sensor generating a vacuum pressure level signal based on a pressure of the vacuum supply;
• a controller coupled to the vacuum sensor, the controller generating a vacuum pump switch signal based on the vacuum level signal;
• and
• a vacuum pump coupled to the controller, and generating vacuum for the supply based on the vacuum pump switch signal.

A method comprising the steps of:

• a) sensing a pressure level of a vacuum source;
• b) comparing the sensed pressure level with a first predetermined level;
• c) activating a vacuum pump to generate vacuum for the source, if the sensed pressure level is determined in said step (b) to be less than or equal to the first predetermined level;
• d) comparing the sensed pressure level with a second predetermined level greater than the first predetermined level;
• e) deactivating the vacuum pump if the sensed pressure level is determined in said step (d) to be greater than or equal to the second predetermined level;
• f) sensing a brake fluid signal used to operate a brake system of a vehicle towing the trailer;
• and
• g) generating a vacuum control signal with the vacuum source to operate a trailer brake system, based on the brake fluid signal sensed in said step (f).