Having tried to remove my corroded MAF brackets previously it resulted in spinning the captive bolt in the air box lid as the nuts were so corroded. Thinking I would have to cut them off, drill them out and fit new bolts as others on here had done previously there was nothing to lose making a last ditch effort. Having used it to good effect to remove rust from other parts I decided to try putting the whole thing into a citric acid bath and seeing if it could penetrate the rust in the threads and free it up. So having removed the actual MAF sensor from the housing (actually the hardest bit) which requires a special security star head bit with a cylindrical cut out in the center, I made a 1 part citric acid crystals to 19 parts hot water solution in an old tile adhesive bucket. Having fitted an old home brew heating belt around the bucket to keep the solution warm (chemical reactions being faster at higher temperatures) left the whole lot in for three days until the bracket surfaces were virtually clear of all rust. I then rinsed it under the tap, dried it with paper towel and sprayed WD-40 Specialist Fast Release Penetrant :yikes: onto the threads three or four times over an hour and left it to work overnight. Next day applied more WD-40 and using a small ratchet handle held near the fulcrum initially tried to tighten the bolts using as little sustained pressure as possible then tried slackening using the same process. Eventually the nut gave very slightly on tightening (initially I thought the captive bolt had started to turn). When I tried again in the opposite direction it gave slightly more and on repeating, the movement became greater to the point it started to undo and could be removed completely. To my amazement the other two nuts did the same. After cleaning up the plates and nuts with a dremmel they are somewhat pitted but with rust treatment and spray of paint would be perfectly serviceable. I have purchased the stainless steel plates and nuts from Alfaholics in the meantime but at least I haven't had to butcher the air box lid.
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