Ford Super Duty Knuckle Vacuum Seal Installer 205-830

A steel axle shaft and knuckle vacuum seal installer that replaces Ford service tool 205-830 and OTC 6695. It is made for the 4x4 front axle on 1998-2004 Ford Super Duty F-250, F-350, F-450 and F-550 trucks, the generation that uses vacuum-actuated automatic locking hubs.

On these trucks the front hubs are locked and unlocked by vacuum routed through the steering knuckle, and the knuckle vacuum seal is what keeps that circuit sealed around the axle shaft. When that seal leaks or gets installed crooked, the hubs will not engage or drop out of four-wheel drive under load, and you chase vacuum lines that are not the problem. Any time the axle shafts come out for u-joints, ball joints or a knuckle rebuild, the seal should be replaced and set with the right tool.

On the bench: install the new seal in the knuckle bore, fit the installer over the shaft, and draw the seal in square and to full depth. The tool keeps the seal from tipping in the bore, which is what normally causes a vacuum leak on a fresh repair. Check hub engagement with a hand vacuum pump before the wheel goes back on.

All-steel construction, about 9.2 lb. Seals are not included.