What is the normal operating temperatures for the front disk brakes of a 99 Camry?

toyota
camry

#1

I just had a brake job done last week on my 99 Camry, the left front rotors were replaced, the disk was “recut”, and a brake system was flushed. The rotors had excessive wear on them, the right front rotors were fine. Before the repair, I had noticed a very small (controllable) shimmy in the steering wheel at 40mph and at 60mph. The car would steer straignt.

Since then, I am drive about 30 to 40 minutes commute each way and I am still smelling hot brakes. I went by a friends house about 30 minutes away, and he brought out an infrared spot thermometer. The left front disc measured 400F, the left front wheel 375F. The right front disk 250F and the right front wheel measured 225F. Please note, I am near Phoenix, and when we measured the temps the air temp was easily over 105F.

Are these temps normal or high?

The emergency brake is hand operated, but does it operate the drums in the rear or the disks upfrront?

This car is a manual so I know how to slow down by upshifting.

No, I am not leaving my foot on the brake pedal.

What causes the brakes to retract when I lift my foot off the brake pedal? Could there still be something wrong with that part of the brake system?

The car has 185k miles on it.

Thanks for your comments


#2

one more comment, now the car wants to pull ever so slightly to the left at highway speeds.


#3

Have you talked to the shop that did the work ? If not don’t wait too long because they may only have a 30 day warranty.


#4

It’s hard to say whether individual brake temps are normal because they depend entirely on how much braking you do, how hard you brake, how heavy the vehicle is, etc. However, it’s very easy to say that one brake should not be almost twice as hot as the same brake on the other side.

Your left caliper is sticking. If the shop didn’t replace the caliper, then they aren’t at fault for that, but it does need to be addressed. If the shop did replace the caliper, then you probably got unlucky and got a bad replacement caliper, and the shop will almost certainly replace it again for you at no charge.

Note that when I say the shop isn’t at at fault for that, I mean that the shop didn’t break your caliper and you will need to pay for a new one. But I do think the shop should have checked to be sure the caliper wasn’t sticking when they saw the clue that your left brake was much more worn down than the right brake. Brakes should wear pretty evenly if everything’s working right. Excessive wear on one side indicates that side is being applied when the other side isn’t, which generally only happens when your caliper is stuck.

It’s possible you had gunk built up in your brake lines, and bleeding the lines squeezed that gunk into the caliper where it’s now blocking fluid from exiting the caliper when you take your foot off the brake pedal.

It’s also possible that the flex line that hooks in to the caliper has collapsed internally with the same result.

To directly answer your question, the brakes get applied when brake fluid is forced into the caliper by you pressing on the brake pedal. When you take your foot off the pedal, the hydraulic pressure goes away, and so the caliper opens again.


#5

The left caliper is sticking, not fully releasing pressure on the pads. This means there is drag in the left front wheel causing friction, causing the greater heat compared to the right wheel.

The caliper could be bad, the pads may not have been installed properly causing the sliders to hang up. There can be a deteriorating brake line that is collapsing internally and not allowing the pressure to release, this is usually the rubber section of the brake line.

That left front brake needs attention. Since it was likely dragging before you had the brake job I’d not be happy with the job done by the shop. They should have expected a greater issue with that brake due to the heavier wear on the rotor causing it to need replacing. This isn’t rocket science and should be easy to figure out.


#6

The more definitive question is whether the temperature is consistent from right to left.

If I understood the post correctly and the shop cut the left front rotor only, this idiot doesn’t know what he’s doing.

Now to the real problem: Your left front caliper is sticking. You need new calipers in the front (the age of the car suggests that both should be changed) as well as new pads and rotors. I urge you to find a better shop. The things the first guy did were not good practices… and he clearly failed to fix the problem.


#7

I agree with TSMB. They should NEVER replace just one rotor. Ever. Makes me doubt their abilities.


#8

You may not need a new caliper. The most common cause of your condition is the caliper bushings are sticking.

You have a piston on one side of the caliper only. When you step on the pedal, brake fluid pushes the piston out and that pushes the inner brake pad out to the rotor. The the additional pressure pulls the outer pad in. When you release, the piston retracts a little and the both the inner and outer pads move slightly away from the rotor.

The forces to draw the outer pad in are far greater when the brake is applied than the forces that move the pad back out when the brake is released. A bushing that is not free to move can hold the outer pad against the rotor with just a little pressure, just enough to heat up the rotor more and wear out the outer pad quicker.

The simple fix is to remove the bushings and lubricate them with a high temp synthetic or silicone grease. Bushings are the term that Toyota uses, most mechanics refer to them as caliper pins.

I am concerned about the competence of the shop you are using. The fact that the left rotor had more wear than the right should have alerted them to the stuck bushings (pins). They should have replaced both rotors, not just one. I suspect that your outer left disc pad was worn far more than any of the others.


#9

On a '99 I’d replace both calipers. They’ve served the vehicle well. Time for them to rest.
Calipers contain elastomeric seals. They’re subject to wear and to degradation of the seals themselves due to time. IMHO if they’re sticking at this age they’re due.


#10

Good question…the answer? It varies…all depends on what youre doing. However you should NEVER be able to sizzle water after a drive with little to no brake activity taking place…

Great time to invest in an infra red thermometer…I use mine all the time for this very thing.

My guess? Since you had prior rotor warpage? As @“the same mountainbike” mentioned…calipers. You may very well have a failing or locking up caliper…can be the caliper…and less common…the hose to the caliper. However it is most often the sliders for said caliper that can cause this…and if they are doing their job just fine…its the calipers. The rubber seals harden over time and heat and age…and when they harden…they dont retract the caliper piston like they are supposed to…this leaves them pushed up against the rotor…and drags the brakes. This will warp a rotor post haste…again and again.

Blackbird


#11
What causes the brakes to retract when I lift my foot off the brake pedal?

Besides the effect of the fluid pressure, there’s various springs that help the brakes to retract. In the power booster, the master cylinder, and often the brake pedal under the dash has a retracting spring too. I don’t recall if there’s a spring in the caliper piston or not.


#12

I don’t think there are retraction springs in the calipers. The rubber boots probably do a bit of retraction, and the minor movement of the disc also pushes the pads away. You don’t want them far from the disc, anyway.


#13

Most brake rotors that I’ve measured the temp on…will usually test out at less than 175 degrees when working good.

But where my shop is, it is almost a mile of straight road for them to cool a bit before I need to brake to pull into the yard and once more to shop at the shop door.

Yosemite


#14

The rubber piston seal in the caliper pulls back a bit.


#15

The piston seal is designed to retract the caliper a bit. It distends when you press the pedal and returns to its static shape when the force is removed, pulling the piston back.

In addition, there’s a spring in the pedal lever that pulls the brake rod back, reconfiguring the valves in the power booster to equalize the pressures on the front and back of the diaphragm… but the vacuum placed on the hydraulics by that system is used to refill the master cylinder from its reservoir rather than to retract the calipers.


#16

It doesn’t retract. You simply remove pressure from the pads but they still contact the rotors. The pads are always dragging on the rotors.


#17

Square cut caliper piston seals stretch when the brake is applied and retract the piston a few thousands of an inch when released.


#18

A person could easily get an estimate how much force disc brake pads are contacting the rotor with the brake not applied by jacking up the rear of the car and spinning the rear wheels by hand. I’ve never done this b/c I’ve never owned a vehicle with rear discs. With rear drums from what I’ve tested, the wheel spins pretty much completely free of brake friction. This test wouldn’t work as well on the front b/c the wheels have to spin the transmission output gear too. But on the rear wheels of a front wheel drive car, the main friction source preventing the wheels from spinning freely is the pads and rotor contact.


#19

Good illustrations, Nevada. That’s exactly what I was describing verbally… but an illustration is worth 1,000 words. :smile: