Uneven brake wear - need advice

[ChrisH]

I just changed my front brake pads over the weekend because the right front pads reached their wear limit. My concern is that the right front seems to wear a lot faster than the left front. If I recall correctly, the front pads start at 9mm thickness when new. The left front outer pad was at 2-2.5 mm when I replaced it. The right front inner pad had 3 to 4 mm left. (The lesser part towards the outer edge of the rotor). The left front pads were 5-6 mm thickness. Hence, in the time the left front worn down from 9 to about 5.5 mm (3.5 mm worn off) the outer right front pad wore down from 9 to 2 mm (7 mm loss).

When I brake on clean dry pavement with the brakes slightly warmed, I don't notice the car pulling at all. However, every once in a while (rare), it seems that the right front ABS intervenes at moderate braking when I don't think it should. That seems odd.

On cold brakes, sometimes the car will pull left or right briefly. I haven't noticed one direction more than the other.

Does anyone have any insight? I can make some guesses:
a) Maybe the right front rotor needs to be turned (rough surface). However, if it was wearing the pad off that much quicker, I would expect the car to be pulling to the right when braking. Or, since the pads still slight touch the rotors even when released, maybe some roughness on the rotor is wearing the pads when not braking.
b) Maybe since there tends to be more sand and dirt on the right hand side of a two lane road (which I drive a lot), then maybe the right side is simply picking up more grit, causing uneven wear.

By-the-way, this was the easiest brake pad replacement I have ever done. Save some money and replace front brake pads yourself. Thanks Lotus for using such an easy system. The rotors also look very easy to take off and put on as well. (Unlike my 92 Honda Accord, which is a huge pain.)

[sleepless]

I'll vote for (b)...

[nocash]

How many miles are on the car?

[EburgE]

Originally Posted by ChrisH

Maybe since there tends to be more sand and dirt on the right hand side of a two lane road (which I drive a lot), then maybe the right side is simply picking up more grit, causing uneven wear.

I say yes. I removed all four wheels this weekend (after 5K miles) to clean the rims and retorque the lugs. The curbside wheels were noticably dirtier and required more scrubbing than the driver's side.

[YAUDI]

Not sure if you track at all, but this is some info on my experiences. I also noted fairly uneven wear with the OEM rotors with OEM pads and Porterfield R4S pad (which I don't recommend). Check out my thread:
http://www.elisetalk.com/forums/show...ight=dba+rotor

Not to say the DBA rotor solved anything, but the pad wear is basically even with the Porterfield R4 pads. I all cases, I never noticed any weird brake feel or characteristics, brakes fine, just some interesting wear patterns...

[esprit89]

What percentage of the time are you running clockwise vs counter-clockwise at the track? I could see the outside higher loaded tire doing more braking work and hence more wear. Do the rear pads show a simliar wear pattern?

Michael

[YAUDI]

Originally Posted by esprit89

What percentage of the time are you running clockwise vs counter-clockwise at the track? I could see the outside higher loaded tire doing more braking work and hence more wear. Do the rear pads show a simliar wear pattern?

Michael

What are you, some kind of an Aerospace Structural Analysts or something... If you're talking to me, probably 80% is CCW on the various tracks I drive... That would make sense with the RHS wear a bit faster, but I always brake in a straight line , yeah always...

[esprit89]

Originally Posted by YAUDI

What are you, some kind of an Aerospace Structural Analyst or something...

Hey! I resemble that remark.

Originally Posted by YAUDI

If you're talking to me...

Opps... my super quick initial glance of the thread somehow made me think we were talking about your car.

ChrisH, you wouldn't by chance frequent CCW tracks also would you?

[ChrisH]

Further info:

Track time: None (just some practice AutoX events)

Miles on car: 14,000, but that doesn't matter much. What matters is how much and how hard I brake. I drive twisty roads to and from work, so there is a good amount of braking (much more than freeway driving).

New pads: I did switch to Porterfield R4-S pads. I bedded them in Saturday, but thought they were slippery at then end of the bedding session (even after a few miles of driving to cool them down). I couldn't even get the ABS to engage at the end. But, by the next day at the May 26 Club111 San Diego AutoX event, they felt good and the ABS clearly intervened on some sections of hard braking. So, I think the pads are okay, at least from a 2 day of use point of view.

Comparison to Rear pad wear: The rear pads seem to be wearing fairly evenly (right side about same as left). It was just the fronts that had the very uneven wear rate. That might weaken or even invalidate hypothesis (b) in post #1.

[R'elise Me]

Just saw this thread. I'm replacing pads on a tracked car that had the same unevenness, but in reverse (driver side wore much faster). Most track days I've done are CW which supports the theory that the outside wheel (and in this case the heaviest loaded front wheel) wears fastest.

[2sporty]

9mm thickness front pads when new seem a little thin.

here's what I measured from Porterfield pads:
new front R4 pad
13.8mm
new rear R4 pad
12.5mm

[Buz]

As I was leaving a track day this weekend my brakes made a horrific squealing grinding sound. My left front pads are metal to metal. The other 3 corners look to have about 50 percent pad left. Bleeding the brakes last week they all seemed to have at least half left. The car has about 9k on it but only 4 track days, 3 of which were ccw. It never pulled to either side but the last session I had to brake a little earlier toward the end as the last of the left front pads were used up.

[jordantii]

Originally Posted by 2sporty

9mm thickness front pads when new seem a little thin.

here's what I measured from Porterfield pads:
new front R4 pad
13.8mm
new rear R4 pad
12.5mm

9mm is just the friction material not the entire pad thickness which would include the backing plate. I think that is what you measured.