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Brake Life?


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We have an '06 RX 400h with just under 49k miles. Our dealership just told us we need all new brake pads, and strongly pushed us to getting all new rotors because, you know, they always recommend replacing the pads & rotors at the same time. This is going to run us well over $600, but for some reason (I may be alone in this) I'm just don't have faith that my dealership is being honest and straightforward with me. So I'm looking for some opinions...

What should we be expecting for brake life? I thought with the regenerative braking system that we'd see longer brake life. We had a 4-Runner before this from which we got longer brake life.

Do we really need to replace pads + rotors at the same time? Or are we just being hosed?

--Crandaddy

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49K miles is certainly not bad for a 4700-lb vehicle, but as Randy stated, driving style can make a huge difference. I teach my teens early during their driving permit lessons that they should take advantage of a heavy vehicle's momentum by coasting as much as possible, which both saves gas and lengthens the life of the brake pads. Most vehicles' rotors can be "turned" on a brake lathe at least once before needing to be replaced, but honestly, if the rotors are not warped or out of flatness specification, they need only a "roughing up" before the new pads are installed.

I would ask the service manager if he can show you how far out of flatness the rotors are, as well as what the factory spec. is. If the flatness is out of spec, then why would removing a small amount of the rotor's thickness NOT be acceptable?

Dave

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49K miles is certainly not bad for a 4700-lb vehicle, but as Randy stated, driving style can make a huge difference. I teach my teens early during their driving permit lessons that they should take advantage of a heavy vehicle's momentum by coasting as much as possible, which both saves gas and lengthens the life of the brake pads. Most vehicles' rotors can be "turned" on a brake lathe at least once before needing to be replaced, but honestly, if the rotors are not warped or out of flatness specification, they need only a "roughing up" before the new pads are installed.

I would ask the service manager if he can show you how far out of flatness the rotors are, as well as what the factory spec. is. If the flatness is out of spec, then why would removing a small amount of the rotor's thickness NOT be acceptable?

Dave

+1

With the hsd doing regen (especially true w/ the AWD version which regens from 2 axles), it's easy to take your pads all the way out to 70K. Ours are over 30K miles w/ almost no signs of wear ... maybe less than 20 thousandths. But of course, gunning it to the next red light means you'll have to stomp harder than just regen depth on the brake pedal ... which is about 2/3 of the way down. Some have actually had light rust buildup on the rotors due to lack of brake / rotor contact. As for new rotors at such an early stage? That raises a red flag ... as in maybe the dealer is unnecessarily making money off the customer. Wouldn't be the 1st time that's happened.

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I got porked at 25k, for the famous brakes and resurfacing. I must admit, I was surprised. I drive very gingerely, and in the summer easily attain 32-33mpg (just to give you an idea).

I had brought the vehicle in for the usually 25k oil and inspection, but was surprised. I should of asked for the old brake pads, as proof. I always get excellent service, but for some reason I didn't quiet feel that day, to question there integrity and honesty. But, I should of.

As a bonus, though, the lexus service technician (aka, mechanic) did take the time to resurface, clean and spray paint the rotors flat black, as well as the calipers. They look a million times better than before.

getting 47k I believe is awesome, for brakes and pads. Of course, it depends on driving style.

I believe the driving style has alot to do with it. I figured, if you are using regenerative braking, the physical application of pads on rotors is zero, and the electrical motors resistance is used as friction aka braking. Apparently, the service advisor said no, that brakes are always part of the equation. I find that counter productive, but logical in the sense of safety. Anybody care to chime in?

Cheers,

MadloR

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I figured, if you are using regenerative braking, the physical application of pads on rotors is zero, and the electrical motors resistance is used as friction aka braking. Apparently, the service advisor said no, that brakes are always part of the equation. I find that counter productive, but logical in the sense of safety. Anybody care to chime in?

Cheers,

MadloR

I do not see how you could have a safe, smooth feeling braking system without the brake pads and regenerative braking system working in parallel. Does anyone know what activates and modulates the regenerative system? It "feels" like it may be brake fluid pressure or other measure of brake pedal applied force , which would mean both friction braking and regenerative braking would act concurrently and increase as brake pressure is increasingly applied.

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I would get a second opinion from another shop or another dealer.

My Lexus dealer has measured the pads my RX 400h on 4 separate service visits over the last 40K. At 30K I still had 8.0mm remaining on both front and rear pads. Plotting out the wear trend projects that I will not need to replace my pads (2.5mm or less remaining) until after 75K.

And I am not easy on this car. My gas milage has barely stayed above 20mpg because I'm an aggressive driver. And I'm not the most fastiuous on keeping the car clean. That said, I do drive mostly on LA streets, so if you drive alot in dusty or muddy situations, your wear may be worse.

BTW, I just looked at my rotors and there are no grooves or warping that would indicate they need to be resurfaced. Judgding by the nearly undetectable lip on outter edge of the rotor, I estimate that no more than .003" of wear has been put on these rotors in the last 40K mi. Resufacing will often take off ~.010" form each face and typically Toyota rotors are only good for 1 or 2 such proceedures before they are out of spec (too thin to carry away the heat).

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I can't speak for your Lexus dealer, but I have encounter numerous "recommendations" over the years to replace rotors on my various Porsches, all long before the rotors had reached factory mininum thickness. Owner beware.

Tom

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