Auto Brake Wear for 2003 Forester Subaru

[W. eWatson]

Automatic. Doesn't down shifting create wear on the transmission? It's not the only hill around here. I'd probably wear out my hand down shifting.

[W. eWatson]

I suspect you are correct. Even though my dealer is 30 miles from here, I think I may let them do it again. However, I think the local mechanic I now use is pretty good. BTW, it's down hill to the dealer. :-)

[Doug Miller]

So what if it's automatic; you still downshift on long and/or steep downgrades to save the brakes. The wear on the transmission is negligible, and, in any event, safety is the prime concern here.

Good rule of thumb: if the hill is so long, or so steep, that you can't stay under the posted speed limit (or posted advisory speeds for curves), plus about 5mph, without using the brakes, you should downshift. Failing to do so can result in complete brake failure.

[Doug Miller]

You didn't answer my question: do you slow down only by stepping on the brakes? Or do you shift the transmission to a lower gear too?

[dpb]

...

Some, sure, but not a concern of noticeably shortening transmission life.

As others noted, however, the difference between recent performance and original would appear to be mostly related to difference between the OEM and replacement pads rather than driving habits.

Over the length of a 600-ft hill unless it is very steep indeed (which, of course, it _could_ be, particularly if it's inside a development or a private drive as opposed to maintained public road) I'd not expect to be able to attribute that much difference in wear to simply a tendency to not downshift. Of course, it would be a reasonable practice as noted elsewhere (altho the limitations outlined in at least one response are far in excess of reason on the side of reality, however, imo).

In particular, of course, if one has an automatic that has an overdrive or similar "mileage" gear, simply shifting down to the fixed gearing ratio below it will cause engine braking that wouldn't get otherwise.

[Rick-Meister]

This will probably start a flaming session on this thread, but here are my thoughts.

40-60K on OEM pads is typical. However, it really depends on the vehicle. I've seen some Chrysler minivans wear out a set of OEM pads in as little as 28K. I've also seen some vehicles get 80K.

On replacement pads, it's really a matter of putting in a quality set. There are NO industry standards on what you can call a premium pad. Zip, nadda. So the cheap crap that's coming in from China is all labeled PREMIUM. It's such a huge problem that the reputable brake friction companies have started an independent testing lab to test their products. If it's B.E.E.P. or D3EA certified, it's a quality product.

When it comes to the type of friction material, you can't just go with a blanket statements that ceramics are better. Ceramics offer some advantages, longer life isn't one of them. They are really designed for quieter operation and less brake dust, as opposed to semi-metallics which offer the best heat dissapation and stopping power. Ceramic composition varies from manufacturer to manufacturer. Again, no industry standard.

Same thing with rotors. The economy rotors are the worst. You can buy a name brand Wagner or Raybestos rotor and an economy rotor for the same vehicle, and the economy rotor will weigh less, have thinner friction surfaces, and fewer cooling vanes. They don't fit on the hub as well and that can cause them to warp faster. Because they're made from cheaper metals, they can chew up a set of pad mighty fast. It's the rotors job to absorb and then dissapate heat quickly. If it's thinner right out of the box, you're compromising safety. Tests by Raybestos show greater stopping distances with economy rotors.

The other thing many shops overlook is the operation of the rear brakes. They only do 20% of the braking, but if they aren't working properly, that extra 20% on the fronts really puts them over the edge. That means properly adjusting the rears, making sure the self adjusters work, and checking the operation of the proportioning valve.

[W. eWatson]

Right foot only. For all 85K miles.

[W. eWatson]

To various posters on this thread,

This is the bottom of the big hill, Ridge and Nevada City Hwy. The top is up Ridge Road about 3/4 of a mile. When I reach the top, I then descent 200 feet down to my house. It's hilly and curvy.

So I go up a hill from around A every day, then down a 200' hill to my house. I do go the other way when I leave the house. Lots of hills, and curves. Stop by some time and I'll take you for a ride.

[Me]

"W. eWatson" wrote in news:29Lrk.18644$ [e-mail]:

hey, I think I pass by in the opposite direction every day. Howdy!

[Doug Miller]

Well, that's why your brakes are wearing out prematurely: you're not downshifting the transmission on the downgrades. Again, obsessing over the difference between 40K on the OEM pads, and 20K on the replacements, misses the point: your brakes are wearing out faster than they should, because you're using them too much.