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Corbet
01-27-2011, 04:05 PM
MUD tech has become so diluted lately I figured I'd ask here.

I need to do the front axle service this year before CM. Figure I'll throw on new rotors and pads while in there. I have 57K on the current parts. Still OK, but nearing end of life.

Planning DBA 4000 6x6 wiper slot rotors and 100 series OEM pads.

What say you?:beer:

coax
01-27-2011, 04:19 PM
I've no experience with that combo, but the only thing I remember reading on mud is that the 100 series toyota pads works with the 80 series toyota rotor. Meaning some folks were having issues with aftermarket stuff being a bit thicker than OEM and not quite fitting.

How long have folks been getting out of the 80 series pads? My understanding is that the 100 pads give you longer life due to larger surface area, but that's it. For my usage, I don't need extended life out of brake pads as I don't put that many miles on the cruiser in a year.

When I did my brake job I got napa rotors and OEM 80 series pads. Seem to be doing ok. I did notice a slight warp in one of the rotors up in Jackson hole, coming down teton pass in 10 below weather. I suspect it was a temporary thing due to extreme variations in temps, as its not present any more. :twocents:

60wag
01-27-2011, 04:28 PM
That's the combo I'm running (DBA slotted and OE 100 pads) and have no complaints. The shims won't fit behind the pads due to pad thickness but I've had no noise issues that make me want the shims.

Corbet
01-27-2011, 04:34 PM
Christo?

Hulk
01-27-2011, 04:43 PM
I'm running 100 series pads with stock rotors. No room for shims. Much longer life.

corsair23
01-27-2011, 07:16 PM
I'm running 100 series pads with stock rotors. No room for shims. Much longer life.

x2 - If you really want, you can put the shims back in once the pads wear down a bit

Seems to stop fine, for a tank :hill:

That said, from what I've read and heard, rotors and pads are one area where many Toyota purists don't subscribe to the "OEM is better" thing and go with well known aftermarket stuff...

Corbet
01-27-2011, 07:43 PM
I guess I don't understand everyone's complaints on life span. I've got 57K on my currents and don't "have" to replace them but plan to as I'll have the axle apart. Seems like many on MUD blow through rotors in 20K. I must drive too responsible?

corsair23
01-27-2011, 08:09 PM
I guess I don't understand everyone's complaints on life span. I've got 57K on my currents and don't "have" to replace them but plan to as I'll have the axle apart. Seems like many on MUD blow through rotors in 20K. I must drive too responsible?

You obviously drive like an old lady! :hill:

Honestly, I don't know. I've only put about 40k miles on the LX since I bought it and replaced the pads/rotors before the old ones were worn. About the same for the 80 but fewer miles...Guess I'll know how long 100 series and 80 series pads last for me when these finally wear down from new :)

rover67
01-27-2011, 09:18 PM
You know, I have run OEM 4 runner pads on my 60 with Brembo rotors from Tire Rack.

I think the rotors are fine as long as folks have used them before and they don't warp which it looks like the DBA's fit the bill.

SO go for the DBA's.

BUT, II have also run the Hawk HP plus ( I think they are the "street" pads now) befor these OEM ones and I liked them a LOT more. Much "grabbier" and I loved the pedal feel. They lasted a while, dunno how long. I never got them to fade even when flogging it coming down from boarding and going WAY too fast.

The OEM pads have worn nicely, but they don't have as good a feel as the Hawks. They have also faded on me before.
So, I don't know if you want to experiment, but I am going back to the Hawks before Cruise Moab. My brakes need to be gone through anyways. I may just skip to their super duty pads.

The super duty ones are on sale for the 80's on tirerack even.

http://www.tirerack.com/brakes/brakes.jsp?make=Hawk&model=HP+SuperDuty+brake+pads&group=HP+SuperDuty+brake+pads&autoMake=Toyota&autoModel=Land+Cruiser&autoYear=1997&autoModClar=

powderpig
01-28-2011, 07:30 AM
What my experience has been. The 100 series pad not only got more life, it did seem to increase brake performance. But only if the whole system was working good. Meaning the calipers are in good shape, brake lines in good shape, fluid in good shape, master cylinder in good shape, etc.
I think any good aftermarket rotor will be a good choice(DBA, Brembo), even some chinese stuff has come up in quality(just depends on where you want to spend your money).
I have not tried aftermarket pads in the past, but may here soon.
As for the life of the stock pads, some model years have softer pad material. Best pad year for an 80 series is for a 1997, not any of the earlier one.

SteveH
01-28-2011, 10:28 AM
I get ~12K on my '95 FZJ out of standard front 80 series pads and rotors - mostly in-town stuff by my non-road-racing wife. This truck (and my brother's '94) have never done any better on pad life.

I compared 100 and 80 series pads side by side at the dealership last week. The 100 pads are thicker and have 15-20% (my guess) more surface area. I can see how the 100 series pads would last longer, and why you cannot use shims. If I were starting with new or turned rotors, I'd switch to 100 series pads.

treerootCO
01-28-2011, 10:59 AM
I am running the Powerstop rotors, that Slee sells, on all four corners. I took them to Mountain High and had all of the rotors cryoed. Pads are OEM 100 up front and OEM 80 in the back. I do not take it easy on my brakes and everything is holding up very well compared to cars I have owned in the past. You could run the Hawk performance pads and increase your stopping ability as well as your rotor life but, the pads wear faster and will need to be replaced more often. So far my rotors are not wearing and my brake pads look new. I think I have about 25,000 miles on them so far.

TIMZTOY
01-28-2011, 11:16 AM
The only reason your getting more life is because the pad is thicker. Your not going to get any extra performance from 100 pads because your still squeezing them with the same calipers. The shims are there for a reason. Yea it wo t effect braking mechanically but. Geeze. Your talking 1/32 - 1/16 of an inch of extra pad. Thts nothing in the form of life. And I'm sure the 100 pads are also more expensive. So unless your just wanting to say u have 100 pads on a 80 I dont see the point.

Like the hilux trucks and minis. We upgrade the solid axle calipers to IFS calipers. Because they have a larger bore diameter = more pressure on pads = better braking.

SteveH
01-28-2011, 12:12 PM
For the record, 80 and 100 series pads (for 1995 and 1999) are priced the same price at my dealership.

subzali
01-28-2011, 01:24 PM
Force = Pressure * Area. Increasing the pad area with 100 series pads, while maintaining the same pressure of the 80 series calipers, equals higher clamping force.

coax
01-28-2011, 01:56 PM
Force = Pressure * Area. Increasing the pad area with 100 series pads, while maintaining the same pressure of the 80 series calipers, equals higher clamping force.

I think this may be a bit off. Pressure (as in PSI) already includes a dimensional component (Square inch).

For braking, the force due to friction (ie the rotor and pad) = the coeffiecent of friction of the two materials and the normal force pushing them together. (IE the force coming from the Master cylinder, through the fluid, and into the caliper, and then through the piston). There is no area component to the frictional force.

So on paper, given the same pad materials between the 80 and 100, there would be no change in braking force because the surface area of the pad doesn't play into the equation. Now how the theory and math translate over into real world experience, is anyone's guess, as some folks do report better braking with the larger pads.

wesintl
01-28-2011, 02:19 PM
:MEH:

carquest rotors and 80 pads.

IMHO toyota pads are too much $ now. probably go with hawk pads in the future.

subzali
01-28-2011, 02:29 PM
I think this may be a bit off. Pressure (as in PSI) already includes a dimensional component (Square inch).

For braking, the force due to friction (ie the rotor and pad) = the coeffiecent of friction of the two materials and the normal force pushing them together. (IE the force coming from the Master cylinder, through the fluid, and into the caliper, and then through the piston). There is no area component to the frictional force.

So on paper, given the same pad materials between the 80 and 100, there would be no change in braking force because the surface area of the pad doesn't play into the equation. Now how the theory and math translate over into real world experience, is anyone's guess, as some folks do report better braking with the larger pads.

Okay, I agree with you that the clamping force (normal force) is not higher with larger pads because the piston diameter of the caliper doesn't change in the case of using 100 series pads in 80 series calipers. But wouldn't the coefficient of friction change due to the different pad size/shape?

nakman
01-28-2011, 02:42 PM
Good choice Corbet with the slotted rotors, staying away from the drilled ones. Drilled rotors aren't good for 80's that plan on a lot of Moab creek crossings, from my experience.

I'm swinging mine back the other direction though... vatozone rotors and stock pads in back, still have slotted/drilled DBA's in front though, 100 pads, though when/if they warp again I'll probably go cheap on the rotors. Only reason I'd stick with 100 series pads at this point is because I've also got a 100 series. I tear my axle down at least once every 2 years, I may as well just do $25 rotors. ymmv :thumb:

coax
01-28-2011, 02:45 PM
But wouldn't the coefficient of friction change due to the different pad size/shape?

I don't *think* so. Coefficient of friction should only be primarily affected by material composition, and then secondarily by wet/dry, temperature, etc. I think the big exception to this would be when the area is reduced to the point where the given pressure is enough to make the one of the surfaces deform. (IE each of 4 pistons would be capable of giving X lbs of force, and then divided by the surface area of the 2 pads, giving you a PSI pressure.) Like if you got a rock stuck in between and it started scoring the rotor. (At which point the area would decrease drastically, increasing the pressure on a given spot on the rotor. But as long as the rotor and pad don't deform (this may actually happen to a small extent) the braking force should remain the same regardless of pad area. Real world I'm sure its much more complicated and that's what the engineers get paid the big bucks for. Kinda fun to think about though!

nakman
01-28-2011, 03:16 PM
Yeah Corey, but remember Subzali's is one of those engineers.. I suspect he's working up an illustration and formula diagram on this now. :)

subzali
01-28-2011, 03:39 PM
well, I had the engineering school, but lack of practical application in the last few years has left me quite rusty, as you can tell from above...:o

I have been learning a lot about brakes lately though because my Tundra has the famous pedal pulsation problem, which supposedly is corrected by the upgraded later 1st gen calipers/pads (as recommended by the TSB). Though there is debate about what actually helps cure the problem. Now that we're talking about this I wonder if the piston size increased from early 1st gen to later 1st gen Tundras, but supposedly the pad size increased as well (though not much from what I hear). There is also speculation that the larger size (as well as the supposedly larger mass) of the later calipers helps absorb more heat away from the rotor. I dunno, I'm hoping to investigate more once I get both sets in my hands when I do my replacement.

nakman
01-28-2011, 04:19 PM
Yeah Matt the piston size increased in the newer calipers, and the overall size of the caliper increased as well. That's what makes your current calipers so desirable in the Taco/4Runner crowd, because they're a nice upgrade to their relatively puny mini-truck calipers, but yet still small enough to fit inside those 7" rims. In fact, if you decide to upgrade, PM Hudo4 here, I bet he'd like to put them on his 4Runner. When I had a Taco and did that upgrade, it was like switching from V-brakes to disks on a mountain bike, I almost went over the handle bars the first time.