Front rotors

[Guest]

I love my both of my Subaru's..Great cars...However, I'm really getting
tired of warped rotors on my '97 and '01. I've replaced the '97 rotors five
times in 155k miles, and had each turned once in between replacement. My
'01 is on its second set of rotors in 25k. I drive in Miami's wonderful
traffic; 70 and stop, 70 and stop.... Does anyone know of an after-market
pad/rotor combo that will eliminate an obvious Subaru design short-fall?

Thanks,

Marty

 

[Edward Hayes]

Something is wrong. I have my originals that have never been turned in
98,000 miles on my 2000 Forester. Either someone doesn't know how to
retorque wheel lugs or the driver is really heating them up by
dragging the brakes. I've never had to turn or change a rotor before
100,000 miles except when damaged by hitting a curb very hard.

 

[John]

I love my both of my Subaru's..Great cars...However, I'm really getting
tired of warped rotors on my '97 and '01. I've replaced the '97 rotors
five times in 155k miles, and had each turned once in between replacement.
My '01 is on its second set of rotors in 25k. I drive in Miami's wonderful
traffic; 70 and stop, 70 and stop.... Does anyone know of an after-market
pad/rotor combo that will eliminate an obvious Subaru design short-fall?

First, make sure your rear brakes are working, sounds like only the front
brakes work and are doing all the stopping. Otherwise your only option
would be to get vented rotors that are cross-drilled so the heat disapates
quicker.
But I have to ask why replace them after only 1 turn? They should be thick
enough to have turned four, maybe 5 times...

 

[Jim Stewart]

Something is wrong. I have my originals that have never been turned in
98,000 miles on my 2000 Forester. Either someone doesn't know how to
retorque wheel lugs or the driver is really heating them up by
dragging the brakes. I've never had to turn or change a rotor before
100,000 miles except when damaged by hitting a curb very hard.

Agreed. I have 116k and original rotors. The
only mistake I made was putting NAPA pads on the
rear once. Now there's significant groves on the
the rear rotors and they sometimes squeak.

I'll change the rear rotors next time, but the
fronts are still servicable.

 

[Carl 1 Lucky Texan]

I love my both of my Subaru's..Great cars...However, I'm really getting
tired of warped rotors on my '97 and '01. I've replaced the '97 rotors five
times in 155k miles, and had each turned once in between replacement. My
'01 is on its second set of rotors in 25k. I drive in Miami's wonderful
traffic; 70 and stop, 70 and stop.... Does anyone know of an after-market
pad/rotor combo that will eliminate an obvious Subaru design short-fall?

Thanks,

Marty

The 'warped' rotor for many of us is actually a heat spot on the rotor
that is altering the structure of the alloy. Likely caused by panic
stops that greatly heat the pad/rotor followed by sitting still with the
hot pad in one spot preventing cooling in that local area. You could try
to train yourself in those panic stop situations to use the handbrake
for the last 1 mph and for holding the car until acceleration is
requred. There is an article at Stoptech's website (IIRC) about this
subject. I suspect a lot of vehicles other than Subaru would be prone to
this condition. I also agree that double checking the rears would be a
good idea. There are some very exotic and very expensive materials made
into rotors and pad nowadays but I doubt you would want to spend
thousands per wheel to solve the problem.

Carl
1 Lucky Texan

 

[Jim]

The 'warped' rotor for many of us is actually a heat spot on the rotor
that is altering the structure of the alloy. Likely caused by panic
stops that greatly heat the pad/rotor followed by sitting still with the
hot pad in one spot preventing cooling in that local area. You could try
to train yourself in those panic stop situations to use the handbrake
for the last 1 mph and for holding the car until acceleration is
requred. There is an article at Stoptech's website (IIRC) about this
subject. I suspect a lot of vehicles other than Subaru would be prone to
this condition. I also agree that double checking the rears would be a
good idea. There are some very exotic and very expensive materials made
into rotors and pad nowadays but I doubt you would want to spend
thousands per wheel to solve the problem.

Carl
1 Lucky Texan

I've had similar problems with my '97 Legacy Brighton Wagon. Most
recently had pads and rotors replace, rotors turned at 7000 mi and
now same problem 6000 miles later. I don't believe I make panic stops
as described above.

Other than the "feel" of warped rotors, how much decrease in brake
effectiveness might there be? It would seem like there must be some
if the pad is only partly contacting the rotor.

Jim

 

[Carl 1 Lucky Texan]

I've had similar problems with my '97 Legacy Brighton Wagon. Most
recently had pads and rotors replace, rotors turned at 7000 mi and
now same problem 6000 miles later. I don't believe I make panic stops
as described above.

Other than the "feel" of warped rotors, how much decrease in brake
effectiveness might there be? It would seem like there must be some
if the pad is only partly contacting the rotor.

Jim

That's a very good question. Not sure for most of us that braking
effectiveness is reduce a LOT - but no one wnats reduced braking
effectiveness, plus it's an annoying problem.
here's the article I mentoned;
http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

Carl
1 Lucky Texan

 

[Carl 1 Lucky Texan]

That's a very good question. Not sure for most of us that braking
effectiveness is reduce a LOT - but no one wnats reduced braking
effectiveness, plus it's an annoying problem.
here's the article I mentoned;
http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

Carl
1 Lucky Texan

here's an excerpt from the article;annoying. More than that becomes a real pain. When deposit are present,
by having isolated regions that are proud of the surface and running
much hotter than their neighbors, cementite inevitably forms and the
local wear characteristics change which results in ever increasing TV
and roughness.

Other than proper break in, as mentioned above, never leave your foot on
the brake pedal after you have used the brakes hard. This is not usually
a problem on public roads simply because, under normal conditions, the
brakes have time to cool before you bring the car to a stop (unless,
like me, you live at the bottom of a long steep hill). In any kind of
racing, including autocross and "driving days" it is crucial. Regardless
of friction material, clamping the pads to a hot stationary disc will
result in material transfer and discernible "brake roughness". What is
worse, the pad will leave the telltale imprint or outline on the disc
and your sin will be visible to all and sundry.<<<<

Carl
1 Lucky Texan

 

[lkreh]

Something is wrong, but it's not the rotors. I have a '99 OBW with
about 118K miles and I'm on my second set of rotors. Five sets in 155K
is way beyond normal. It could be a number of things. My first guess
is that the lug nuts are being overtightened -- that's a known cause of
warped disks in Subarus. There are torque specs in your owner's manual
-- get a torque wrench and check them yourself.

It could be your driving style, but you'd really, really have to get on
the brakes heavily and frequently to go through five sets of rotors
(you did mean rotors and not pads, right?) in 155K miles. You could
survey a couple of dealers in your area and ask what's typical of other
Subaru drivers in Miami (if there are any others ;>|).

 

[Tom Reingold]

I love my both of my Subaru's..Great cars...However, I'm really getting
tired of warped rotors on my '97 and '01. I've replaced the '97 rotors five
times in 155k miles, and had each turned once in between replacement. My
'01 is on its second set of rotors in 25k. I drive in Miami's wonderful
traffic; 70 and stop, 70 and stop.... Does anyone know of an after-market
pad/rotor combo that will eliminate an obvious Subaru design short-fall?

Thanks,

Marty

I bought a used Subaru in March. The rear rotors were bad, so the seller
replaced them before I bought the car. A couple of months later, the new
rear rotors were shot. My mechanic noticed one of my calipers was
sticking. He says he fixed it so it won't stick. I hope so. If not, I'll
be buying rotors and calipers.

 

[Alan Ronemus]

This isn't the fault of the rotors, and they most likely aren't warped. I
had mine resurfaced several times over the years and it always returned. It is
actually the pads, which use an organic binder. When the pads are heated as
after a hard stop from high speed, the binder cooks out of the pad and deposits
on the rotor. Since the binder has a higher coefficient of friction than steel,
you get a sharp grab each time the pads pass over the deposit. The only cure is
to switch to aftermarket performance pads (I use Hawk brand Street Performance
pads) on the front brakes - they use a ceramic binder. An added benefit is that
the mushy, vague feel of the factory brakes is much improved. If they were
available for the rear the brake feel would be excellent. The performance pads
cost ~3 times what OEM replacement parts do (and only a little more than Subaru
charges at their parts department), but are well worth it.

 

[hippo]

I believe you but I'm shocked!

91 Liberty (Aus) mnl wgn with 33200Km (20700Ml) - original rotors all
round and *no* turning.

99 OBW auto with 145000Km (87000Ml) - original rotors and rear pads and no
turning.
BTW we drive our cars enthusiatically but sympathetically with a wide
range of roads, loads and conditions.

Someone's earlier suggestion to check your rears sounds like a good
starting point. Personally I'd also get the whole system flushed, refilled
& bled if it hasn't already been done as part of regular servicing. Cheers

 

[k. ote]

Other than proper break in, as mentioned above, never leave your foot on
the brake pedal after you have used the brakes hard. This is not usually
a problem on public roads simply because, under normal conditions, the
brakes have time to cool before you bring the car to a stop (unless,
like me, you live at the bottom of a long steep hill). In any kind of
racing, including autocross and "driving days" it is crucial. Regardless
of friction material, clamping the pads to a hot stationary disc will
result in material transfer and discernible "brake roughness". What is
worse, the pad will leave the telltale imprint or outline on the disc
and your sin will be visible to all and sundry.<<<<

Carl
1 Lucky Texan

Thank you, Carl, you saved me the effort.

 

[k. ote]

The only cure is to switch to aftermarket performance pads (I use Hawk
brand Street Performance pads) on the front brakes - they use a ceramic
binder.

Unfortunately, some of these performance pads require extra heat, initially,
to get them going. Be careful about ceramic pads: some motorists won't be
familiar with the initial lack of brake-power on them after a long drive
with no brake use and then sudden braking. It'll be something like:

.. Foot down, hard. "Look out for the deer!"
.. Too little stopping power.
.. Foot down, harder.
.. Brakes heat up, begin to provide more stopping power than OEM.
.. Driver is jacknifed into his steering wheel, and the tires are tortured.
Bambi escapes, unharmed.

Granted, that's at the extreme, but if you want pads that resist the heat
better than OEM, *and* you can't get illegal materials (like asbestos) you
have to accept that they have special requirements that go along with their
special abilities.