FJCruiser low brake fluid spongy pedal

That sounds concerning. I had a similar experience with my old Volvo a few years back. The brake pedal felt spongy, and the fluid was disappearing. I initially suspected the master cylinder, but it turned out to be a combination of worn pads and slightly weeping brake lines. The pads were thin enough that the calipers had to extend further, requiring more fluid in the system, which caused the level to drop.

Thank you for the insight! How did you pinpoint the brake lines as the culprit? I haven't noticed any visible drips, but I'll definitely inspect them more closely. Also, did you experience any changes in braking performance, like increased stopping distance, along with the pedal feel?

Well, I didn't see any drips at first either. The lines were just seeping a tiny bit, enough to lose fluid over time but not enough to form a puddle. My mechanic found it by carefully inspecting the lines and fittings. As for the braking performance, yes, the stopping distance did increase noticeably, especially in wet conditions. Given the age of your FJCruiser, I would highly recommend having a professional inspect the entire brake system, including the lines, calipers, and master cylinder. It's better to be safe than sorry when it comes to brakes.

I appreciate your advice. I took it to a trusted mechanic, and you were right! The front brakes were indeed worn and one of the rear brake lines was seeping fluid. We replaced the front pads and rotors, plus the rear brake line, and performed a complete fluid replacement. Total cost was 480€. The brake pedal feels normal again, and I have peace of mind knowing the system is sound.