I noticed leakage around the rear end on my 93 Breakaway. When I finally opened the fill plug (12MM allen)air escaped? I don't understsnd how air pressure built up. It also calls for 6 qts. to fill. After putting in 6 qts. of 85-140 the level was not near the fill plug. I put in another qt., and still could not feel the oil. How do I check for full?

Don, there should not be any air pressure in that rear end. They all have vent tubes on top of the casing that need to be cleaned manually every once and a while. It is not uncommon for the fill plug to be higher then required oil level. I would lower that level to what is recommended by the ownner's manual.

Don: on the top of the rearend housing out close to the rear spring you will see a thing that looks like a small pipe screwed into the housing with a little top hat on it. If you turn cap you will see dirt fall out of it, the cap should be free and loose as this is the breather and lets out the pressure created inside when the grease is spun around going down the road. If this device gets cloged it usally makes the rear axle seals leak.