The RAS 115 is basically a small angle grinder or angle polisher. The lock button usually pushes a pin into the gear housing to temporarily lock the gear for changing the pads. The gear housing on angle grinders are usually about half filled with grease. Over time the grease used can separate causing oil to leak out of the tool.
Try running the RAS for a few minutes and then then put your hand on top of the gear housing. If the gear housing seems uncomfortably hot the tool should probably be sent in to festool to be relubricated, and to check if any oil leaked elsewhere including into the motor, which can be sort of a mess. If the tools gear housing still seems to run cool there might not be much of an issue. Probably half the power tools I've owned that had gear housings have had a bit of oil leach out, some when they were brand new.
I'm not sure who supplies the grease for the Festool power tools. Neither the Festool manuals or parts list, list a Festool parts number for the grease or other lubricants used in the various tools, which would likely vary by the tool model. I have some other grinders made by Flex, another German power tool manufacturer, that also likely used to manufacture some tool models for Festool, and may still. The Flex tools use two or more Renolit brand greases made by Fuchs lubricants. The lubricants are either a proprietary blend or at least have a custom model number for Flex. I mention the Flex grease because some of the tools were purchased as display models from someone in Canada and they had an issue with excessive grease leakage. I have other Flex brand tools purchased from retailers in the USA and have not had the same problem. I have sort of wondered if some issue such as possible the possible lower temperatures found in Canada would be more likely to cause some types of grease to separatemore readily or quickly. Lack of frequent use and agitation can also cause certain types of grease to separate over time, but I believe the flex tools I purchased from various sources may have all been the same aproximate age, and according to the part lists the tools use the same type of grease.
I wouldn't just think of just adding more grease either since some types of greases are completely non compatible. If for some reason you did choose to do this you would need to thoroughly clean all the old grease before adding new grease.
