(a) Except upon full payment of the indebtedness the holder shall not release a lien or other right in or to property held as security for a guaranteed loan, or grant a fee or other interest in such property, without the prior approval of the Secretary, unless in the opinion of the holder such release does not involve a decrease in the value of the security in excess of $500: Provided, That the aggregate of the reduction in the original value of the security resultant from such releases without the Secretary's prior approval does not exceed $500.
(b) Except upon full payment of the indebtedness or upon the prior approval of the Secretary, the holder shall not release a lien under paragraph (a) of this section unless the consideration received for the release is commensurate with the fair market value of the property released and the entire consideration is applied to the indebtedness, or if encumbrance on other property is accepted in lieu of that released it shall be the holder's duty to acquire such lien on property of substantially equal value which is reasonably capable of serving the purpose for which the property released was utilized.
(c) Failure of the holder to comply with the provisions of this section shall not in itself affect the validity of the title of a purchaser to the property released.
(d) The holder shall notify the Secretary of any such release or substitution of security within 30 days after completion of such transaction.
(e) The release of the personal liability of any obligor on a guaranteed obligation resultant from the act or omission of any holder without the prior approval of the Secretary shall release the obligation of the Secretary as guarantor, except when such act or omission consists of
(1) Failure to establish the debt as a valid claim against the assets of the estate of any deceased obligor, provided no lien for the guaranteed debt is thereby impaired or destroyed; or
(2) An election and appropriate prosecution of legally available effective remedies with respect to the repossession or the liquidation of the security in any case, irrespective of the identity or the survival of the original or of any subsequent debtor, if holder shall have given such notice as required by § 36.4280 and if, after receiving such notice, the Secretary shall have failed to notify the holder within 15 days to proceed in such manner as to effectively preserve the personal liability of the parties liable, or such of them as the Secretary indicates is such notice to the holder; or
(3) The release of an obligor, or obligors, from liability on an obligation secured by a lien on property, which release is an incident of and contemporaneous with the sale of such property to an eligible veteran who assumed such obligation, which assumed obligation is guaranteed on his or her account pursuant to 38 U.S.C. 3712; or
(4) The release of an obligor or obligors as provided in § 36.4279.
(5) The release of an obligor, or obligors, incident to the sale of property which the holder is authorized to approve under the provisions of 38 U.S.C. 3714.