I have a 1984 mercedes and it uses 5 vacuum pods to control the hvac flaps. Most of the rubber diaphragms in the vacuum pods are ripped and dont hold vacuum anymore. I am replacing all of the rubber diaphragms but using the old pod housing. I noticed when taking apart the old vacuum pods the rubber diaphragms had some sort of white chalky residue on them. I didnt think anything of it until i got the new vacuum pod diaphragms and they actually are covered in a white powder. I looked up what the white residue could be for generic rubber parts with a white residue and they say it can be mold release agent. But these new diaphragms have more than a white chalky residue you can scrape off with your finger. Its more like the new diaphragms were dipped in talcum powder and then shaken off so they are left with a fine powder all over the diaphragm. Im beginning to think this is actually there on purpose to help the diaphragm roll against itself. Because when vacuum is applied to the pod the diaphragm gets pulled down and the sides fold up over itself. Before i got the new diaphragms my idea was to clean the new rubber up and then coat it with aerospace 303 protectant but now im thinking i should just leave the white powder and not clean the diaphragms before installing them. So my question is is should i clean and coat the diaphragms in 303 or should i leave the poweder on there which is either mold release agent not cleaned off or some sort of lubricant?