oil leaks while running

That's probably tranny fluid ,Lay clean cardboard down when you park it to see

Red/pink color is transmission fluid, the fact that it leaks when driving can be a few things, the front pump seal is getting worn, the transmission is overheating due to a plugged cooler. A scanner should have the ability to read transmission temp as you drive in live data mode, the front seal will be obvious to a transmission shop. Get it checked before it is winds up costing you a transmission.

On a twenty year old Ford van, it would be unusual for it not to leak. It's likely that the leak is just a loose fitting in the trans fluid cooler line that runs from the transmission to the radiator. Park in a clean spot and watch for drips, then look up to find where the leak is. Or just go to a transmission shop to have this checked.

Initially after finding oil on the driveway I took the van to my mechanic who said the rear main seal was leaking.I poured 16.9 bottle of Bar's leak Rear Main Seal Repair with the next oil change and drove the van for a while.At next oil change I asked the mechanic to check if there is any leak in that area and he found none.Recently I noticed when I stopped after a long drive on hot day with a loaded cargo trailer behind there was a small puddle red/pinkish oil like like liquid on the driveway. I changed the position of the van and parked it overnight.I found no new signs of leakage under the van.all my oil levels are pretty much ok.I did not use the a/c on this trip and inside the cabin it got pretty hot.There is no gauge to tell me that my transmission got hot .There was no malfunction of transmission . I am wondering where this initial pool of red/pinkish liquid is coming fro.I see some wetness under between engine and transmission but no dripping.I would appreciate your thoughts.Look alike when start to brake on downhill slop my van leaks leaving a trail behind till I stop when a puddle. Thanks