After it warms up, I'll be doing the front brakes my 99 forester:

 

- new pads & rotors

- overhaul front calipers

 

I'm also planning on replacing the front hub seals and repacking the front wheel bearings while I have things apart, reason being it's usually a faulty seal that allows the grease to leak out and/or water and other debris to enter thereby causing bearing failure. I have 131K miles on this car at the moment.

 

Is this a task worth doing?

 

At what mileage and age have you suffered front wheel bearing failure (the rear wheel bearings on these cars are an entirely different story)?

Hm...not sure if it helps but typically on wheel bearings when replacing an axle, I replace inner oil/grease seal and slather some Neo HP800 wheel bearing grease in there. I haven't had any of my 3 soobs experience wheel bearing issues (yet) but have only had them for a few years.

as far as i know i still have the origional wheel bearings.... i have 187,000 on my 96 legacy and i havent had to do them yet....

The bearings are sealed, you can clean the dust seal and put a little grease on it as well as the axle splines.

Well, it's true that these sealed bearings don't require routine maintenance, and like porcupine I replaced the inner seals when doing the drive shafts but used Mobil 1 grease on the lip.

 

However, I have a Hub tamer so I could perform the overhaul on-car without messing with the alignment, and this is the only reason why I'm even considering replacing the seals and repacking the bearing as preventative maintenance.

Since you have a hub tamer, and wanting to take the time to repack the bearings, wouldn't it be cost effective and take the same amount of time to just replace the bearings? That way, you would have full assurance that your wheel bearings will last a good long time since they would be new.

Well, in theory, the wheel bearing if properly lubricated should last the life of the vehicle, but it's the rubber seals that usually fail, resulting in bearing failure.

 

Sometimes, drive shaft service will ruin an otherwise fine wheel bearing when undue force is applied to remove the drive shaft from the hub and/or if the axle nut is not properly tightened.

 

Other times a seized caliper and resultant overheating can fry the seals, which again results in bearing failure.

 

My thinking is that by preemptively replacing the wheel bearing seals while I'm doing the brakes, I should never have to replace the wheel bearing itself.

 

I know the norm is to wait until they make noise and then replace everything as you suggested, which is what I did with a rear wheel bearing on my car, but it's my nutty proclivity for experimentation that drives my curiosity.

... but it's my nutty proclivity for experimentation that drives my curiosity.

I call this: The Zen of Subaru ownership.

I would replace the wheel bearing completely if you're going to get it to the point where you're reaplcing seals. I had a front wheel bearing go out on me at 110k and reaplced both sides as a precautionary measure. The bearing itself isn't that expensive and should be easy to access with the work you're doing. Good luck.

What year is your car? Do you drive much on unpaved roads? Any brake front brake issues prior to wheel bearing failure? 110K miles seems a bit premature.

 

It's true that the bearings themselves aren't all that expensive, especially if you get the Koyos, which IMHO are very good. So it's not the cost but curiosity that concerns me.

 

Like fixing an oil or coolant leak, except with the distinct difference that it's much more labor intensive to check and replace wheel bearing grease and seals, I'm curious to see how long the the original bearings will last with an overhaul.

 

I call this: The Zen of Subaru ownership.

So you've read the Pirsig classic?