Spongy Brake Pedal Points to Dangerous Fluid Leak

I faced a similar issue with my A3 2016 gasoline model last year and have some experience with hydraulic brake problems. The symptoms you describe match what I encountered, spongy brake pedal and low brake fluid levels. After a thorough brake inspection, the workshop discovered worn brake pads had caused damage to the rotors, and there was a small leak in one of the brake lines. The master cylinder was also showing signs of wear, contributing to the inconsistent pedal feel. The complete fix included: New brake pads and rotors, Replacement of damaged brake lines, Brake fluid flush and replacement, Master cylinder rebuild Total cost came to 480 Euro for parts and labor. The warning light came on shortly after I first noticed the spongy pedal, which was a clear sign to get it checked immediately. Could you provide: Current mileage, When was your last brake service, Are you hearing any unusual sounds when braking, Has the brake warning light activated This information would help determine if your issue is similar and provide more specific guidance.

Last service was at 194000 KM, current mileage 199663 KM. No unusual sounds during braking, and no warning lights. Just noticed the brake pedal starting to feel different in the last weeks. The brake fluid level is indeed lower than usual, but I will get it properly checked soon. After reading about master cylinder issues and brake system problems, I want to avoid any brake failure risks. Thanks for sharing your experience with the spongy brake pedal, seems my symptoms match what you described.

Thanks for the additional details. Given the mileage and your description, it sounds even more similar to what I experienced. After 190000km, wear on brake system components is common. The lack of warning lights in your case is actually good news, when my master cylinder was failing, the brake warning light came on pretty quickly. The gradually developing spongy brake pedal without warning indicators often points to normal wear rather than sudden failure. My advice based on the shared symptoms: Get a brake inspection soon while the issue is still mild, Have them check brake fluid for contamination, Request inspection of brake lines for potential small leaks In my case, catching it early helped avoid more extensive brake system damage. The spongy pedal got worse quickly once it started, and waiting would have led to higher repair costs. Total preventive maintenance ended up much cheaper than my 480 Euro repair bill because I waited too long. A basic brake service with fluid change typically costs about 150 Euro-200 Euro if no major components need replacement. Given your car is a similar model and the symptoms match, definitely worth getting it checked before the brake pedal feel deteriorates further.

Thanks everyone for the detailed replies. I will schedule a brake inspection this week, better to be safe than sorry with brake issues. The comparison with your experience really helped understand what might be going on with my hydraulic brake system. Based on the symptoms and age of my car, I suspect it needs more than just a brake fluid replacement. Will ask them to thoroughly check the brake lines and master cylinder condition during inspection. Good point about preventive maintenance being cheaper in the long run. I will make sure to have them check for: Brake fluid contamination and levels, Brake line condition and potential leaks, Master cylinder performance, General brake pad and rotor wear Better to address the spongy brake pedal issue now while its still manageable. The repair costs mentioned give me a good baseline for what to expect. Will update once I know what exactly needs fixing in my brake system.