in the fluid reservoir there is a black rubber plug with slits, under this plug I find 1 hole about 1/6 of an inch and next to it another dimple that looks like it may be another hole. so the question is ,is there 1 hole or 2 under this plug? forgot to mention it’s a 91 trx 300 front brakes are hydro drums and back is manual drum. can the cylinder bore be honed or is a new one the best option?