How long do rotors last?

[PT1]

Originally Posted By: ryland
I was planning on just cleaning them up with brake cleaner and green scrubby pads.


Try cleaning them up with emery cloth and brake cleaner. If the front ones are ventilated and the webs in the center are not too corroded kepp them. But do mic them to be sure you are in the safe range.

 

[1993_VG30E_GXE]

I'm still using my original 16 yr old rotors (Maxima). 320,000+ KM city driving. While doing my repairs for the last 4 months they sat outside and got rusty as [censored] so I just hit them with a wire brush on the die grinder and cleaned them up nice.

 

[artificialist]

Originally Posted By: 01rangerxl
They are self adjusting.

Nearly all cars built after the 1970s have self adjusting drums, but I have always found that the factory adjusters don't take up all the slack that they should.

 

[Vizzy]

I think many people don't know that even though modern drum brakes do "self adjust" they do need occasional resets from you, the driver, to have the self adjuster work properly occasionally you should put the car in reverse and roll back a bit followed by a firm application of the brakes a couple of times.

 

[RacerE7773]

Not long on GM vehicles.

 

[daves87rs]

I've got 50k on the OEMs in my Balt....

 

[severach]

Drum brakes when serviced properly self adjust to the extents for the life of the brakes. If they need a reset then they weren't done properly in the first place. I know because I did mediocre drum brake work for years so the adjusters were hit and miss. I knew the car company could assemble brakes that self adjusted most of the time so I learned myself to do them properly. Now I get tall brakes that don't degrade as the shoes wear.

It is unlikely that any driver could avoid reverse so completely that the rear brakes would go out of adjustment.

 

[labman]

Funny none of the 5 things I have bought new came from the factory with self adjusters properly installed to work. Includes one japanese import.

 

[UNC017]

If you replace the pads before the rivets chew into the rotor so that all you have to do to the rotor is break the glaze with a scotch-brite pad, the rotors can last a very long time. This is especially true with softer brake pad materials. One of the 2 rotors on my 438,000 mile Satellite is original to the car, and still in spec because it only had to be turned once or twice at a minimum cut over all those years. But the trend these days is to harder pad materials, like ceramic, that will wear the rotor far faster than old non-metallic or even semi-metallic pads so the rotors will have a significant lip that and require turning probably within every 100k miles at the MOST, maybe more often. Modern rotors are also typically thinner to start with than in bygone years, so there's less meat to start with. And some high-performance types aren't meant to be turned at all.

 

[UNC017]

Originally Posted By: Vizzy
I think many people don't know that even though modern drum brakes do "self adjust" they do need occasional resets from you, the driver, to have the self adjuster work properly occasionally you should put the car in reverse and roll back a bit followed by a firm application of the brakes a couple of times.


That's not a "reset," its that drum brake self-adjusters ONLY ratchet to take up slack when the brakes are applied in reverse. If you never applied the brakes in reverse, the self-adjusters would never do ANYTHING at all. If you're in the habit of rarely applying the brakes firmly while backing (say you always back uphill out of your garage, like me, and barely have to touch the brakes before shifting into drive) then you might have to consciously apply the brakes firmly while backing from time to time to get the adjusters to work.

 

[H2GURU]

Totally depends on the vehicle. If you have disc on front and drums on rear, the fronts will do a disproportionate amount of braking "work". If its a front drive, once again the fronts are working much harder due to uneven weight distribution and warpage is very common with each brake job. Pickups always warp the front rotors too so its been my experience that its actually UNCOMMON to have perfect rotors at brake time! When the discs first appeared they were advertised as a lower cost way of vehicle maintenance but for me anyway... just the opposite has been the case.

Class 8 vehicles went the disc route several years ago and many fleets are now opting OUT and spec'ing DRUMS again so we're not the only ones dissatisfied?

 

[severach]

Originally Posted By: 440Magnum
If you never applied the brakes in reverse, the self-adjusters would never do ANYTHING at all. If you're in the habit of rarely applying the brakes firmly while backing (say you always back uphill out of your garage, like me, and barely have to touch the brakes before shifting into drive)

But you also go to the grocery, the night club, the auto store, the Internet cafe, and the gym. At some of those places you will go in reverse. Sometimes someone else will use your car. When the adjusters work all it takes is once in a blue moon.

I find that the days of the glassy smooth rotors at the end of the pad life are long gone. Most modern rotors including factory rotors are so destroyed from uneven pad wear that they can't even be turned once. They've become as disposable as pads. Up here in the rust belt if you keep the rotor you must wheel out all the hub rust out or you have instant pulsation.

 

[mechanicx]

Originally Posted By: 440Magnum
Originally Posted By: Vizzy
I think many people don't know that even though modern drum brakes do "self adjust" they do need occasional resets from you, the driver, to have the self adjuster work properly occasionally you should put the car in reverse and roll back a bit followed by a firm application of the brakes a couple of times.


That's not a "reset," its that drum brake self-adjusters ONLY ratchet to take up slack when the brakes are applied in reverse. If you never applied the brakes in reverse, the self-adjusters would never do ANYTHING at all. If you're in the habit of rarely applying the brakes firmly while backing (say you always back uphill out of your garage, like me, and barely have to touch the brakes before shifting into drive) then you might have to consciously apply the brakes firmly while backing from time to time to get the adjusters to work.


If I'm remembering correctly there are 2 types of drum brakes-duo servo and leading trailing. I think the duo servo used a lot on older cars would adjust during forward motion. The leading adjust when braking in reverse, but i think some of the adjusted also whenever the parking brake is set. I think I have that straight?

 

[UNC017]

Originally Posted By: mechanicx


If I'm remembering correctly there are 2 types of drum brakes-duo servo and leading trailing. I think the duo servo used a lot on older cars would adjust during forward motion. The leading adjust when braking in reverse, but i think some of the adjusted also whenever the parking brake is set. I think I have that straight?


The only duo-servo system I've worked on wasn't self-adjusting at all, so I don't know how self-adjustment was normally implemented on them. Leading/trailing definitely only increments the self-adjuster when working in reverse, and working sufficiently hard in reverse at that. Not sure about parking brake application....