A thermoplastic melting apparatus (10) comprises a tank (18) pivotally mounted upon bearings (54) within the interior of a housing (12) having a top cover (22). An electrical (140), (142) or mechanical level indicator device (44) is mounted exteriorly of the tank (18) which is effective to sense pivotal movement of the tank (18) as it is loaded with and/or emptied of thermoplastic material (26), and to produce a signal which indicates the quantity of thermoplastic material (26) within the tank (18). The level indicator device (44) is isolated from dynamic forces produced by drive linkages (40) which operate pumps (32), (33) associated with the tank (18), by positioning the pivot axis (51) of the bearings (54) in the same plane as the force produced by the drive linkage (40). The lid (20) of the tank (18) is isolated from downward forces applied to the top cover (22) of the housing (12) to prevent the transmittal of forces to the level indicator devices from objects placed on the top cover (22) of the housing (12) or the like.