By axle seal do you mean the axle boot?And which one, the inner one close to the differential or the outer one, close to the wheel.
Is the leak dark color graphite grease?
If the axle has a play up and down with the vehicle stationary, you should hear some cracking sound when taking tight turns.If that is the case your CV joint or joints have gone south and you should replace them or get a new half shaft which is recomended.
PS.No matter what manufacturer boot you install, the air has to be purged out during installation
in order to prevent unwanted leaking.A new half shaft comes complete with the boots on ready to install.
