I know that some of us out there are still stuck with the old stock vacuum wipers that for some odd reason ford put in Broncos from 1966 to1968 but if your like me and have better ideas on ways to spend my hard earned cash. I like most of the rest of you will most likely retro fit an electric wiper unit at some time but in the mean time we need what we have to work.      In some cases the wipers won't work at all and sometimes you may have to pullout on the switch to make the wiper move down and then push it in to make it return and this is not the way they operate. When hooked up correctly and greased properly they don't work half bad considering they are vacuum driven.      If you just follow the steps below you can have them working like new in less then an hour and at little or no cost. Now just reassemble in reverse order . Remove wiper units from bronco. {See. Fig 1} Remove the cover on the front of the unit. The two small flat head screws hold it on. Pry the hook off the pin but do not remove it. At this time remove the 4 odd screws on the top cover with a pare of needle nose pliers and the two large flat head screws on both sides of the hook. {See. Fig 2} Now remove the cover to the main chamber housing of the wiper {See Fig.2} Now all you have to do is clean and re grease the main chamber. Acetone works good to cut the old dried out grease that you are likely to find gumming up the main chamber and flap valve. Now apply a nice coat of Multi-Purpose Grease {See. Fig 3} and work the flap valve back and forth to spread the grease.      After re-assembly when you turn the wiper shaft you should hear the vacuum entering the unit. Also if for some reason the seal {See. Fig 4} is destroyed on the main chamber cover during removal a new one can be made from light gasket martial from any auto store or some rtv sealant. Good luck. by Bryan E Couch

Click images for a larger version Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5