Modus brake fluid loss

I had a similar problem with my Modus! The spongy pedal feel is really unsettling, isn't it? When the brake fluid is low, air can get into the hydraulic brakes, which are powered by fluid pressure, causing that feeling. Have you checked the rear brake cylinders? They can sometimes leak internally without it being obvious. Also, how worn are your brake pads and discs? Severely worn brakes can cause the fluid level to drop as the caliper piston extends further to compensate.

Thanks for the quick reply! I did have a quick look at the rear cylinders, but maybe I need to take a closer look. What exactly should I be looking for? And how would I know if it's definitely the pads causing the issue?

Okay, so with the rear cylinders, look for any signs of dampness or fluid around the seals. It might be subtle, a slight discoloration even. As for the pads, if they're really thin, like less than 3mm, that's a good indication. Honestly, though, with brake issues, it's often best to get a professional opinion. The whole brake system, including the master cylinder and the brake lines, is pretty crucial for safety.

Thanks a million for the advice! I took it to a mechanic, and you were spot on – the rear brakes were worn causing low brake fluid. Turns out they needed replacing. Cost me 480€, but at least I've got piece of mind now!