All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon Prophet Mohammad and upon all his family and companions.
According to jurists, if the deceased is indebted, then his/her heirs must settle his/her debt as soon as possible because Abu Hurairah (May Allah be pleased with him) reported: The Prophet (Peace be upon him) said: "The soul of the deceased believer remains pending on account of the debt till it (the debt) is repaid." [At-Tirmidhi].
According to scholars of Hadith, (The soul of the deceased believer remains pending) I.e. "Remains detained" Al-Iraqi said: "This soul is pending; it isn`t judged whether it is to be sent to Hell or Heaven until its debt is decided on."
However, the deceased is cleared from liability once his/her guardian pledges to settle that debt, but this is provided that the creditor approval." In case the debt for which the deceased is liable wasn`t settled immediately, the heirs should ask the creditors, before washing the deceased, to make them liable for it and by doing so the deceased becomes cleared from liability." {Hasheyat Al-Khaliobi, vol.1/pp.403}.
We pray that your father is cleared from liability once you (Asker) pledged to settle his debts. And Allah the Almighty Knows Best.