please delete my comments after fixing :)

please change, in mod "753", "752 pack", "754"

* the filename of the .wav in as in the .xml
or
* the reference with filename in the .xml to be as the .wav filename

then restart Mashinky, test the mod with starting a New Game.
there should be no FAILED! lines with your sounds in trace_dump.log as there are now.
if these are fixed, in the Mashinky main menu go to Mods,
select your Mod and click the Mod Tools button.
Then, click the Upload button.
This will upload the new (fixed) version.

This does need to have the same "id" value in \your_mod\meta.xml as the existing id on the Steam Workshop for the existing mod.

in mod 753

\config\wagon_types.xml:
sound_breaks = "sound/753/brakes_brej.wav"

failed to load

filename is: breaks_brej.wav