1999 Lexus GS 400FACTORY OEM SERVICE PROCEDURE

Brake Fluid Level Warning Switch

Remove brake fluid reservoir tank cap and strainer. Disconnect brake fluid level warning switch 2-pin connector. Using an ohmmeter, check continuity between brake fluid level warning switch terminals with float up (switch off). Continuity should not exist. Siphon fluid from reservoir tank. Check continuity between brake fluid level warning switch terminals with float down (switch on). Continuity should exist. Pour brake fluid back into reservoir. If continuity is not as specified, replace brake fluid level warning switch and retest system operation.

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.