CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Hyundai Tucson - self-adjusting brakes?

General Discussion
,
#1

Hello,

I drive a 2007 Hyundai Tucson. I’ve been told by my father (who’s not a mechanic and knows little to nothing about cars) that my vehicle has self-adjusting brakes. Does such a thing exist?

I remember right before I had my new brake pads put on (about more than a year ago), my brake pedals felt “light” and I would have to press down really hard to come to a stop, which prompted the need for new brake pads. At that time my brother-in-law (who is more competent in all things mechanical, electrical, etc.) was pulling the hand brake up and hitting/tapping the brake pedal at the same time, when I told him about the issue.

Another thing I noticed is when I put my vehicle in park, and then pull the hand brake up as much as I can and then tap the brake pedal the pedal sort of “locks”, and when I resume driving it the next day or later on, my braking is a lot better /quicker. Is that a good thing? Should I continue to do that? Again, my father recently told me that pulling the hand brake up too far will cause damage to the brake lines, and that I should only pull it up half-way (which I don’t think does much of anything).

Please advise me on what’s the best thing to do here. Thanks!

#2

First, is this what your rear brake rotors look like?:

#3

Nonsense

Yes

#4

Yeah, I did a quick search on AutoZone and that’s what comes up for the rear brake rotors. Why do you ask?

#5

You’re referring to the self-adjusting brakes as something that exists, correct?

#6

Those rotors have mechanically operated brake shoes inside for the emergency brakes. Therefore, the emergency brakes have no connection or effect on the hydraulic disc brake function.

#7

The e-brake is self-adjusting:

However, putting them on “half-way” probably defeats the self-adjustment feature. [EDIT - probably not self-adjusting…see below.]

#8

Thanks. How exactly does it self-adjust anyway? What effect does pulling the e-brake all the way up, or leaving it down, have on my braking system, and the self-adjustment? Also, does my tapping the brakes until it’s locked (meaning that I can’t press down on it much more) after the e-brake is pulled all the way up, considered good or bad?

#9

I can’t speak to your Tucson, but the parking brake in most cars is self adjusting. How it usually works, it gets adjusted every time you apply it. Likewise, for most vehicles with drum brakes, they are also self adjusting. They get adjusted either by applying the brakes (by pushing on the brake pedal) while backing up, or the same way the parking brake self-adjusts above. Disc brakes are also self adjusting, as that’s built into their basic design. Drum brakes don’t self adjust as well as disc brakes, so the self adjusting feature of disc brakes is one of their advantages over drums.

Your owner’s manual should explain how to work the self adjustment feature in your Tucson. Occasionally on the radio show Car Talk a caller will call in saying their parking brake isn’t working very well. Ray usually tells them to use it more often. Every time you apply the parking brake it self adjusts a little. A lot of folks seldom apply the parking brake, they just put the transmission in park instead, if you don’t apply it often enough it can go out of adjustment.

#10

Looking further, I’m thinking you don’t have self-adjusting e-brakes. They are manually adjusted by removing the rubber plug near the edge of the “top hat” of the rotor and using a screwdriver to adjust the star wheel shown at ‘A’ here:

The rubber plug goes in the biggest hole seen at the top of the disc photo shown.

#11

Total unnecessary action. Just park, pull the parking brake and go about your business.

1 Like
#12

I honestly don’t know if I do or not either, as I am not a mechanic nor do I have any experience with cars aside from driving them for about 5 years. At one point I had tried checking my user manual to see if my vehicle did indeed have self-adjusting brakes, but couldn’t find any evidence of it.

#13

Thanks. Any rhyme or reason as to why the foot pedal locks up when I press it after the e-brake is pulled up?

Sorry for all the questions. I’ve been doing the above for some time now and I don’t want it to cause any damage to my vehicle.

#14

I can’t think of a single car made since 1969 that doesn’t have self adjusting brakes.

Disc brakes are inherently self adjusting. When you step on the brake, the master cylinder pushes brake fluid from the reservoir on top of it (where you check your brake fluid level) into the caliper cylinder. This pushes the caliper piston out toward the rotor. There is one pad between the piston and the rotor. There is a pad on the other side, and by the design of the caliper, it gets pulled in at the same time as the inner pad is pushed out, clamping down on the rotor.

When you release the brake pedal, the only thing that pushes the pad away from the rotor is the tension from clamping. The pads will only pull back enough to release the tension, no further. If the pads wears a little from the stop, it simply will not pull back as far as it once was and void is filled by brake fluid behind the piston. As your brake pads wear down, the level of brake fluid will drop in the reservoir on top of the master cylinder. If you don’t make a habit of adding brake fluid to the full mark all the time, then the level in the reservoir is a good indicator of the wear on your brake pads. When the fluid gets to the minimum, you will need new pads.

The parking brake has an adjuster known as a star wheel. In the old days, a mechanic would periodically adjust this for you. The drum brake used in your e-brake uses springs to pull the brake shoes back so as they wear, they need this adjustment. New drum brakes (since 1969) have a lever attached to one of those springs. When you pull on the brake handle, this lever moves in proportion to the travel of the shoes. If the shoes move too far because of wear, the lever will move the star wheel one click. The next time you use the e-brake, the lever travel should be a bit shorter.

Unless you pull on the e-brake while moving a lot, the shoes get virtually no wear. Just setting the e-brake while stationary causes no friction, therefore no wear.

#15

My 1975 Civic had manually adjusted rear drum brakes.
It also had ignition points and manual choke.

#16

And the new days. Here’s a 2003 Sonata…note no auto adjust feature (bottom adjuster is to the right in this picture):

#17

I’ve yet to encounter a car owner’s manual that explains what you just described

#18

@circuitsmith My 74 Civic had automatic adjusters.

My bad, mine was an 84.

#19

@insightful, maybe they decided that this is only used as an e-brake so it should never need adjustment. No friction, no wear.

#20

The drum-in-hat type parking brakes generally don’t have self adjusting mechanisms, it isn’t needed.