Macaulay Culkin -- Dad Wanted to Patch Things Up Before Stroke

Macaulay Culkin's dad desperately wanted to reconnect with his estranged son -- according to sources close to the family -- and even took steps to end their feud ... but now Kit Culkin is fighting for his life and it may be too late.

Sources tell us Kit -- who suffered a massive stroke in Oregon Tuesday -- told family members he wanted to repair his relationship with Mac ... which soured back in the 90s during a nasty custody battle with Macaulay's mom.

We're told Kit was trying to get Macaulay's number --telling family members to pass the word on to his son -- but they never connected.