The trustee may file an adversary proceeding to obtain a court order avoiding any transfer of the debtor’s property if (11 USC 547, 548):
The debtor is presumed to be insolvent on and during the 90 days immediately preceding the date of the filing of the petition. (11 USC 547) If the trustee claims that the creditor’s lien is void because the debtor was insolvent at the time of levy, the trustee must allege and prove such insolvency. (Liberty Natl. Bank v. Bear, 265 US 365; Travis v. Bixler, 20 CA 2d 279; Fischer v. Pauline Oil & Gas Co., 309 US 294) A petition in bankruptcy does not automatically discharge a judicial lien. The trustee must take positive action to avoid any such acquired lien, otherwise the lien is retained intact by the creditor obtaining it. (Fischer v. Pauline Oil & Gas Co., 309 US 294)