lessee shall keep the equipment free and clear of all levies, liens and encumbrances. lessee,or lessor at lessee's expense, shall report, pay and discharge when due all license and registration fees, assessments, sales, use and property taxes, gross receipts, taxes arising out of receipts from use or operation of the equipment, together with any penalties or interest thereon, imposed by any state, federal or local government or any agency, or department thereof, whether or not the same shall be assessed against or in the name of lessor or lessee