Traveller low brake fluid

Low brake fluid is never good! I had something similar happen on my old Citroen a few years back, turned out to be a leaky brake line. Check all your brake lines and the master cylinder for any signs of leaks. Also, have you noticed any difference in your braking performance, or any unusual noises when braking? I ended up having to top up the brake fluid every other day!

Thank you for your reply. Could a worn master cylinder cause this issue, or is it more likely to be a leak elsewhere in the system?

A worn master cylinder is definitely a possibility, especially with the symptoms you described. It's probably leaking internally, which can be hard to spot, I would still strongly recommend checking the lines! Honestly, a professional check is probably best at this point. I spent ages messing around with that Citroen myself, when I should have just taken it to a workshop.

I appreciate the advice. I took it to a trusted workshop. As suspected, there were worn brake pads and some minor damage to a brake line. The repair cost was 480€. Thank you again for pointing me in the right direction.