How to crawl pdf documents in sharepoint 2010 search,i added a content source but when i search for pdf documents i can not found pdf documents except all documentes,before cumulative updates it was searchable.
In sharepoint 2010, you have to install the pdf Ifilter in order to search the pdf documents.
If you already had that install but after CU it is not working then check the settings if any piece is missing.
Check this blog for complete settings. https://blogs.msdn.microsoft.com/sharepoint_bar__grill/2012/01/30/sharepoint-2010-configuring-adobe-pdf-ifilter-9-for-64-bit-platforms/
In some case u have to run full crawl after cu.