Coolant leaked, flush with vinegar & tap water?
 

1999 4.0 4x4 83k miles
Sat for 4ish years. Needs fluids flushed.

Before I could get to this task truck leaked coolant in about 3 weeks of driving. It has a visible fresh leak streak around water pump. No milky oil but rad. reservoir was dry. To diagnose it and be sure, I want to flush/clean with vinegar and tap water, then drive it about 10 miles/day for about 3 days. I will flush tap water out with distilled water then add coolant. If I leave this mixture in it for 3 days only will tap water affect engine in those 3 days?

I would just flush it with water and leave it at that. Acid is not kind to aluminum.

Not for 3 days.
It's just diluted acetic acid.

Rad barely took less than half a quart of vinegar and it filled up. I thought that thing was empty. It's staying parked, I won't get to flushing it until Sunday.

Sunday is fine, it would take months or even years for vinegar to eat away at the aluminum.