The problem in performance of the part should be described:
1. How it occurred and when, what actions were taken, etc.;
2. The problem area must be indicated (marked) on the part;
3. It is preferable to attach a video confirming the particular defect;
4. Video capture is obligatory in the case of oil and other fluid leaks, air leaks;
5. Parts of the electric circuit - must have a computer error printout or measurement results from an electrician (can be in video format);
6. OE parts: Gas pedals, modulators (OE, Knor-Bremse, WABCO); Electric levelling valves (OE, Knor-Bremse, WABCO); control units (OE, Knor-Bremse, WABCO); control sensors (OE, Knor-Bremse, WABCO); a printout of the error codes must be submitted along with the claimed defective part.