Method for the functional testing of a fluid level warning indicator

A testing method comprising the steps of:

• providing a fluid reservoir having first, second and third chambers, the third chamber being formed by a main chamber and a guiding chamber in fluid communication with the main chamber;
• providing and maintaining a first sensing element in the guiding chamber;
• providing a plunger within an integrated brake controller at a first retracted position and switching a first plurality of solenoid valves into a closed position while a second plurality of solenoid valves are switched to an open position to create a first open flow path from a plunger chamber to the fluid reservoir;
• moving the plunger from the first retracted position to a second extended position thereby exhausting fluid from the plunger chamber into the fluid reservoir via the first open flow path so as to move the first sensing element higher relative to a second sensing element fixed to the fluid reservoir;
• and
• moving the plunger from the second extended position back towards the first retracted position thereby generating a negative pressure in a fluid passageway which connects the third chamber of the reservoir to the plunger chamber so that a fluid stream flows from the third chamber into the plunger chamber via the fluid passageway, the fluid stream directly drawing the first sensing element vertically downward within the guiding chamber toward the fluid passageway such that the first sensing element moves vertically downward in the guiding chamber relative to an upper surface of the fluid in the guiding chamber, the first sensing element moving vertically from an upper position to a lower position relative to the second sensing element as the first sensing element is drawn vertically downward;
• and
• generating a signal from the first and second sensing elements and transmitting the signal to a control unit.

A testing method comprising the steps of:

• providing a fluid reservoir including a guiding section and a projection extending from an inner surface of the fluid reservoir to a terminal end face;
• providing a float having a first sensing element in the guiding section, the float having an engagement surface facing upward toward the terminal end face of the projection, the engagement surface directly contacting the terminal end face when a fluid level in the fluid reservoir is at a predetermined fluid level to maintain the float in the guiding section;
• providing a negative pressure generator;
• generating a negative pressure in a fluid passageway and a chamber which are in fluid communication with the guiding section wherein a second sensing element is affixed to the guiding section;
• transferring a fluid flow stream generated via the negative pressure from the guiding section to the chamber via the fluid passageway, the fluid flow stream drawing the float having the first sensing element downward within the guiding chamber toward the fluid passageway so as to move the float having the first sensing element from an upper position to a lower position within the guiding section;
• generating a signal via the first and second sensing elements as the float moves relative to the second sensing element within the guiding section;
• and
• transmitting the signal to at least one of a control unit or a graphical user display.