Hi need help mechanic is busting me , my entire air syst seems to be contaminated with brownish black type of dirtish oil and its cgging my hoses ruining my braks system and the tanks are all contaminated , do I need a new compressor or is a filter ? the mechanic cleaned the air tanks and they were full of this material , and the air systems is constantly getting clugged ... what coud it be I feel the mechanic is cleaning but not fixing my main problem help!1