I just had my 90K service done at a local Lexus dealer. The rep called me and said that my rear brake pads were at 3/32". I didn't think much at the time and authorized the replacement over the phone. The brake function and parking brake checked out to be normal.

I do wonder, however, why my rear brake wore out so quickly? I don't abuse my brake, frankly I rarely use it for my commute.

For comparison, my front brake pads were replaced under warranty at 42K. And it went from 13/32" at 42K, to 9/32" at 60K, then 7/32" at 90K. The rear brake went from 12/32" at 0K, to 8/32" at 60K, then 3/32" at 90K??? The Lexus rep couldn't come up with any explanation himself. He acknowledged that it was strange.

Is there a possible cause for this? Thanks.

 

I assume we are not tlaking about auxillary brakes. Normally the front pads to rear pad life is 1:1.75

How is real time braking? If the front are not acting properly, then the rears end up doing the extra work. The other issue could be with the proportionating valve (very unlikely but possible)

First, do a brake fluid flush. Purge lines and slave cylenders from old fluid. Most brake problems are due to fluid not moving easily.

In an open parking lot or clear road, try various brake application. From slow to emergency braking.

As you lay down rubber, notice if the rears are more distinct.

Salim

 

if you live in icy areas.. and you have vsc on then it might be wearing the brake pads out when it kicks in.. just a hunch cause mine wear out fast and I only noticed it when I move to IL from TX. I dunno.. might just be me though.

 

Just curious but,

did you have the front and rear calipers serviced at the time the brakes were done.

Inability for the slider pins to move freely on a floating caliper setup (which the Rx has) may cause excessive wear on the pad itself over the long haul.

Just a thought!

 

I don't know whether Lexus serviced the calipers or not. No one but Lexus worked on my brakes. Front at 42K, rear at 90K.

I've had lots of wet and frozen weather during the last two months. The rear wheels always looked dirty. Is it possible that frozen water/road spray might get the calipers stuck?

And yes, VSC came on a couple of times due to ice, but just for about 3-5 seconds total.

My brakes have always worked well and stayed quiet. When should the wear indicator start screeching?

Thanks.

 

Brake screecher should never be counted upon. If I recall correctly, the piece has to be trasnferred from the first brake pad on to the replacement pads. You end up hoping that mechanic has done that.

Nothing like inspecting the pads at each service interval.

There are are indirect ways, like rapid brake-pad dust collection as well as dropping brake fluid level.

Salim

 

I had a Nissan Pathfinder once which had extensive brake work done and within 1 year after the service, one of the front calipers started sticking... Upon closer inspection I noticed that the bonehead mechanic had torn the rubber sleve that protects the slider on the caliper and hence caused it to partially seize..

Doesn't mean this is your particular problem but just a co-incidence that I also had problems after brake service.

Again,
just a thought!

 

That is why one needs to lay down the rubber in a parking lot to figure out what is happening or not happening.

Salim

 

Most cars I have owned seem to go through front pads at least twice as fast as rear pads. I did not find this to hold true with both my RXs. The pads wear evenly front to rear and require replacement at about 75K for my wife's driving style. You mentioned you rarely use your brakes so maybe 90K is a more realistic number for you. It looks like if you didn't change your front pads at 42K the front and rears would have worn about the same and both would have required replacement at about 90K. Not bad for a set of pads. If anything, I would question the accuracy of the rear pad measurment done at 60K.

 

Yes, rear brake wear faster on RX. I finally replaced my rear brake pad last week at 115k miles. My front brake pad still had 30% left. They last very long because I live in so. ca. and the mileage is 90% freeway and 10% city.