brake pedal switch PAI FSW-0491

brake pedal switch PAI FSW-0491Genuine Mack OEM brake light pressure switch (1MR2472M) for Mack heavy duty trucks. Wired into the stop lamp circuit, this normally open switch closes at 4. 0 PSI to illuminate the brake lights when the service brakes are applied a non functioning switch is both a safety risk and a DOT out of service violation. The 1 8" NPT body ships with factory Loctite for a leak free install. PAI FSW 0491 is the verified premium aftermarket equivalent. Signs You

Genuine Mack OEM brake light pressure switch (1MR2472M) for Mack heavy-duty trucks. Wired into the stop-lamp circuit, this normally-open switch closes at 4.0 PSI to illuminate the brake lights when the service brakes are applied — a non-functioning switch is both a safety risk and a DOT out-of-service violation. The 1/8" NPT body ships with factory Loctite for a leak-free install. PAI FSW-0491 is the verified premium aftermarket equivalent.

Signs You Need a New Brake Light Pressure Switch

• Brake lights fail to illuminate when the pedal is applied
• Brake lights stay on continuously regardless of pedal input
• Intermittent operation — brake lights only at hard pedal pressure
• DOT roadside out-of-service citation for stop-lamp failure

Specifications

Cross References

This part replaces or is equivalent to the following part numbers:

• Mack: 1MR2472M, 25165689
• PAI Industries: FSW-0491

Applications

Used across the Mack heavy-duty truck range — the 1MR2472M is the stop-lamp pressure switch on most Mack air-brake circuits, including:

• Mack Anthem, Pinnacle, Granite, TerraPro
• Mack CH, CL, CV, CX series
• Mack RD, R Model — selected applications

Confirm thread size (1/8" NPT) and 4.0 PSI activation match your circuit before ordering. Note: Mack 1MR2472M2 is a different part (A/C pressure switch, PAI LSW-0967) — the trailing "2" matters.