MR2 Brake Fluid Loss

I had a similar issue with my old Saab 9-3, although the symptoms weren't exactly the same. It turned out to be a slow leak in one of the rear brake lines that was only noticeable under pressure. The fluid loss was so gradual that it was hard to spot initially. Were you able to check the flexible brake hoses? Also, how many kilometers are on your MR2's brake pads?

Good call on the flexible hoses. I'll give those a closer look, especially in the rear. The car has 109915 km on it. I'm not sure when the pads were last changed, so they might be worn. Could worn brake pads really cause that much fluid loss and the weird pedal feel?

Worn brake pads won't directly cause fluid loss, but as the pads wear down, the pistons in the calipers extend further to compensate. This increases the volume of the brake system and thus requires more fluid from the reservoir. If the reservoir was already low, or if there's a small leak somewhere, the increased demand could drop the level significantly. Given the age and mileage, a comprehensive brake inspection is advisable. Going to a professional would be a good call.

Thanks a ton for the insight! I checked the pads, and they were nearly gone. Took it to the shop, and they confirmed that plus a small leak at one of the rear calipers. New pads, rotors, and a caliper replacement set me back 480€, but the brakes feel great again. Really appreciate the help!