VW Sharan TDI Owners Report Spongy Brake Issues

I had a very similar issue with my 2013 VW Touran TDI. Given my moderate experience with hydraulic brake systems, I initially thought it was related to the brake components, but it turned out to be an electrical issue causing undervoltage in the brake control module. The symptoms were exactly like yours, inconsistent brake pedal feel and the disc brakes responding differently each time. The workshop diagnosed it by running a full electrical system check. The undervoltage was affecting the brake assist system, making the hydraulic brakes behave erratically. The fix involved replacing the voltage regulator and recalibrating the brake control module. Total cost was 240€ including diagnostics and labor. Before suggesting specific solutions though, could you share: Any warning lights on the dashboard? Have you noticed the issue more during cold starts? When was your last brake system service? Does the problem occur more frequently when other electrical systems are running? This would help determine if your issue is similar to what I experienced. While electrical issues can cause these symptoms, worn brake shoes or other mechanical brake system components could also be the culprit.

Just had my yearly service done last week. For my brake issue, the mechanic performed a thorough inspection of the brake system. The brake calipers were actually fine, but they found air in the brake lines causing the spongy pedal feel. The brake rotors also showed uneven wear. The fix included a complete brake fluid flush, bleeding the brake system, and replacing both front brake pads and rotors. Total repair cost was 580€ including parts and labor. The pedal feel is now firm and consistent. The symptoms match exactly what you described, inconsistent pedal pressure and deep sinking. No warning lights appeared on the dash during this whole ordeal.

Thanks for sharing your repair experience. The symptoms of air in the brake lines can indeed mimic electrical issues, which is why proper diagnosis is crucial. Good that your mechanic caught both the air infiltration and the uneven wear on the brake rotors, these issues often go hand in hand. In my case, after the electrical fix I mentioned, I also ended up needing new brake rotors about 6 months later. The initial electrical problem had caused uneven pressure application through the brake calipers, leading to premature wear patterns on the rotors. Even after fixing the electrical issue, the metal brakes never felt quite right until I replaced the rotors. Your repair cost of 580€ seems reasonable considering the comprehensive work done. A proper brake fluid flush and system bleeding, combined with new brake components, should give you many more years of reliable braking. The lack of warning lights despite the issues shows why regular inspections are important, not all brake system problems trigger dashboard warnings. Going forward, keep an eye on your brake fluid levels and consider having the brake system checked during every service to catch any potential issues early.

Thanks for sharing those details about the electrical fix on your Touran. While my Sharan's issue turned out to be different, it shows how similar symptoms can have various causes. The air in the brake lines plus worn brake rotors definitely explained my spongy pedal feel and inconsistent braking. The complete brake system service fixed my problems completely. After getting the brake fluid flush, system bleeding, and new brake pads and rotors installed, the pedal response is perfect. Interesting that you also needed brake rotor replacement later on, makes sense that the electrical issue caused uneven wear on your brake components. The 580€ repair cost was worth it for reliable braking. Definitely planning to have the brake system checked regularly now during service to avoid similar issues developing again. Appreciate your input about monitoring brake fluid levels too, will keep an eye on that moving forward. Good to know about watching for similar symptoms that could indicate either mechanical or electrical brake system problems. This whole experience taught me not to ignore even subtle changes in brake pedal feel.