Hi, new to the forum and wondering if anyone might be able to help? Appreciate if so. I have a Partner Tepee and have noticed a small leak just in front of the off side rear wheel. It looks like there is some sort of quite large plastic resevoir/container there which leaks a small amount overnight-every night. The brake fluid level seems to stay OK. I wondered what this large ish resevoir was for. Any pointers? Many thanks for reading.