Nothing contained in this act shall be construed to affect in any way whatsoever any waiver of surface support, any release from damages or any other title, right, estate, interest, liability or exoneration, from liability created, granted, excepted, reserved or otherwise dealt with in any deed, agreement of sale, title insurance policy or other instrument in writing, which was executed or delivered prior to the effective date of this act.
52 P.S. § 1554