Hot rotor

[doorgunner]

Sorry Doorgunner, I can't agree with most of what say. The pads on a floating caliper in proper working order should make contact/pressure equally/simultaneously. I would suggest that you look at your Harley carefully as you apparently have a problem.

...

I did....it does---ME! I installed tighter nylon bushings to keep the calipers from rattling so much since my ears are only 48" from the calipers......


It gets worse.....the front cylinder on my Harley catches all the wind---yet it runs 30* hotter than the rear cylinder....maybe that's tired in with the rotors? LOL

I do appreciate your wanting to solve the caliper problem, though....

 

[Jay FX4]

I beleive that most have never used a non-contact thermometer on roters; their use is an excellent diagnostic tool. Because so few have used one, the temperature differential question that I posed is one that few readers here have encountered.

These devices have come down in price to the point where one can be had for as little as $25 form Harbor Freight Tools.

The differential that I've noticed runs constantly at a 20F. Typical the temps are 120F and 140F.


Al, A.S.E. Master Auto Tech./L1

Is this a typical infrared thermometer you're using? If so, does it have adjustable emissivity settings? I have one, and actually use it all the time for various things, from checking the effect of a freon recharge to checking the internal temp of a nuked pot pie. I have never used it on my rotors, but I will try it.

140°F seems like a very cool reading for anything other than a quick trip with little braking.

When I first bought my brand new ZX2 back in '01, I spray painted the calipers with regular spray paint (before I switched to 500° "high heat" paint) and it would get so hot that the paint would bubble - but it only happened on the passenger side, never the drivers side. Uneven pad/rotor wear was never an issue on that car.

My unscientific explanation is that, from pushing the pedal to the actual braking of the vehicle, there are too many links in the chain to expect a perfect 50/50 split between both sides. 20° seems like a very minor difference to me.

 

[Sasquatch_Ryda]

Ditto....I don't think there is a problem there at all....no brake pull...no seized on caliper...no issue.

 

[feellnfroggy]

If the fluid wasnt distributing 50/50 then it would pull to one side or another, Keeping in mind that the zx2 mentioned was front wheel drive. But it occured to me that not all exhaust manifold are symmetrical. Isnt one like a cunt hair closer to the side of the vehicle than the other due to routing? Would it be enough to affect rotor temp anyone think?

 

[doorgunner]

If the fluid wasnt distributing 50/50 then it would pull to one side or another, Keeping in mind that the zx2 mentioned was front wheel drive. But it occured to me that not all exhaust manifold are symmetrical. Isnt one like a cunt hair closer to the side of the vehicle than the other due to routing? Would it be enough to affect rotor temp anyone think?

yep.....along with the hot air from the radiator fan also being deflected in that direction causing the rotor to stay hotter.....(but we still can't rule out gremlins)

 

[--weezl--]

no one has mentioned the fact that possibly the cooler side ISN'T breaking as much as it should, if the piston is stiff or so, it would explain why it's cooler, and why there is less wear...

additionally, 20* is insignificant, and any difference in drag left to right, that would cause a 20* difference (even if there IS something wrong) i don't think would cause a pull strong enough to notice...

 

[AllanD]

OK, speaking as a dealership tech who sees hundreds of sets of brakes in a month, that is normal.


One pad almost always wears out faster. About 90% of them have a 1/32 difference inboard to outboard, and it's usually the outboard that is lower. So unless you have about 6/32 left on the inboard and the outboard is shot, your system is working properly.

Yes, the outboards usually wear faster but do you know why?

It's about airflow, it never occours to most people but normally airflow
through the brakes is from under the vehicle out through the face of
the wheel so the outboard surface of a brake rotor typically runs considerably hotter than the inboard surface

As for specifics on 1983-94 Ranger based vehicles, the pads wearing is often a factor of unever wear on the inner brake pad thrust surface, the "notch" where the tab of the pad goes wears on the steering knuckle.

So those trucks commonly suffer from inconsistant brake performance because the pads are no longer precisely located.
and often fail to release cleanly if not drag.

And it has little to do with the caliper piston sticking.



AD

 

[k3eaxk3eax]

Sorry Allan, I can't agree with either. Perhaps if you re-read my post you will see that I wrote about the passenger-side roter running hotter. Nothing you said would account for such a differential.


Al, A.S.E.Master Auto Tech./L1

 

[85_Ranger4x4]

As for specifics on 1983-94 Ranger based vehicles, the pads wearing is often a factor of unever wear on the inner brake pad thrust surface, the "notch" where the tab of the pad goes wears on the steering knuckle.

So those trucks commonly suffer from inconsistant brake performance because the pads are no longer precisely located.
and often fail to release cleanly if not drag.

And it has little to do with the caliper piston sticking.



AD

That seems to apply pretty well to me. The pads get hung up, don't realease correctly and cause extra wear and heat. He doesn't mention it here but he is refering to wear in the notch where the pad is held. Worth checking into anyway.

 

[k3eaxk3eax]

Again if you read my original post you will see that the calipers were replaced and the slides lubricated and yet the passenger side roter continued to run 20F hotter.

Al

 

[85_Ranger4x4]

Again if you read my original post you will see that the calipers were replaced and the slides lubricated and yet the passenger side roter continued to run 20F hotter.

Al

The knuckle is what wears, you can put as much grease as you want on it and it won't bring back what metal has worn off.

 

[k3eaxk3eax]

Knuckle! What knuckle? The caliper rides on the anchor.

 

[robertc1024]

Yes, the outboards usually wear faster but do you know why?

It's about airflow, it never occours to most people but normally airflow
through the brakes is from under the vehicle out through the face of
the wheel so the outboard surface of a brake rotor typically runs considerably hotter than the inboard surface

As for specifics on 1983-94 Ranger based vehicles, the pads wearing is often a factor of unever wear on the inner brake pad thrust surface, the "notch" where the tab of the pad goes wears on the steering knuckle.

So those trucks commonly suffer from inconsistant brake performance because the pads are no longer precisely located.
and often fail to release cleanly if not drag.

And it has little to do with the caliper piston sticking.

AD

Have to disagree. I just got finished changing the pads on my wife's honda. Both fronts and rears had the wear indicator on the inside pad. All four inside pads were worn way more than the outboard pad. I don't think the airflow matters squat.

 

[kcm1582]

Have to disagree. I just got finished changing the pads on my wife's honda. Both fronts and rears had the wear indicator on the inside pad. All four inside pads were worn way more than the outboard pad. I don't think the airflow matters squat.

That's how most of the brake jobs in our shop are, the inside pads are usually the first to wear out.

 

[adsm08]

Knuckle! What knuckle? The caliper rides on the anchor.

And if I remember correctly, on these trucks, the anchor is part of the knuckle.



We still haven't gotten this sorted out? I'm gonna say it again. Against the +200* that the brakes can achieve when operating your 20* difference is minor and insignificant. It could be something as simple as your test drive track had you only making left hand turns. That makes the rotor on the outside of the turn heat up more because as you ride the brakes through the turn that wheel travels farther.

Wheel going farther under braking = MOAR HEETZ!!!!