How-To Rear Disc Brake Job




Hello! This page is devoted to doing the REAR disc brakes on a 2002-2005 Hyundai Sonata, but it’s the same general idea for any disc-brake setup.

Disc Brakes are pretty easy, as long as you have the right tools, and take your time!

First you'll need some PB Blaster or other penetrating oil.  This breaks the rust/corrosion off and lets you crack the bolts free without breaking them off.  You'll also need a silicone grease or anti seize for the caliper bolts, pins, and new pads.  You'll need a caliper compression tool, or a sturdy C-clamp, and a can of brake parts cleaner.

Brake dust is extremely hazardous to your help, I recommend washing down the oil brake parts before dismantling anything, to keep the dust from getting in your lungs.

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Step 1: How-To Rear Disc Brake Job

 Let's Get Started!

1) Jack up the car, put it on a jackstand, and remove the wheel. (Release e-brake)

2) Stare at the brakes a while, get familiar with the parts.

3) Spray the PB Blaster on the two caliper bolts (back of caliper, top and bottom) and the two Bracket Bolts (back of bracket)  Both are 14mm for the sonata.  Let that stuff sit for 10 minutes or so.

4) Unbolt the Caliper, and tie a bungee cord around it to the upper A-Arm or another sturdy piece of metal.  (Make sure it doesn't pull on or put stress on the brake line!)

5) Unbolt the Pad Holder, and remove the old pads.  Make sure the new pads are the same size and shape as the old ones.

6) Check the rotors to make sure they're the same as well.  Parts store employees sometimes mess up…


Step 2: How-To Rear Disc Brake Job

7) This is what it looks like when you remove the rotor.  The e-brake is a mechanical brake, which pulls those blue shaded shoes against the inside of the "drum" portion of the rear disc.  They can get stuck, or rusted a bit, so lightly tap the drum and the backside of the rotor with a rubber mallet or hammer.  There is a rubber grommet covering the e-brake adjuster if you really need to dial back the e-brake, and/or you can back off the nut of the cable under the center console.

8) Examine inside of old rotors for scoring/damage from e-brake mechanisms

9) Laugh at pathetic old pads.

10)  Many rotors come with a little screw that holds the rotor flush with the hub.  Some people say it's not necessary, but use an IMPACT SCREWDRIVER or it may strip out.  Be sure to use anti-seize when re-applying the screw.



Step 3: How-To Rear Disc Brake Job

11) Grease the sliders and back of the pads nicely.  This cuts down on noise, and extends the life of the pads.  The slider pins must gently be pulled out (be careful of the boots!) and cleaned/ greased as well.

12) Push pads into the Pad Holder, align curve of pads with curve in rotor drum.

13) Take top of the brake master cylinder, and use the rental tool to compress the caliper piston back to allow room for the thicker new pads.  Be sure that there isn't brake fluid leaking, or that the boot is torn.  Ask for assistance if you don't know how to use this tool.  A small C-clamp works too, but isn't as accurate.




Step 4: How-To Rear Disc Brake Job

14) Check caliper, make sure no strain is on it, and install the Pad Holder (grease those bolts!) and pads.

15) Reinstall the rubber grommet, screw (if you haven't done so already), and push pads flush with the rotor.  Make sure the rotor spins freely and doesn't bind (some scraping noise is okay with new brakes)

16) Bolt on the caliper, 20-30 foot lbs (pretty tight) and you're done.

17) Put the top back on the brake master cylinder and BEFORE YOU TURN ON THE CAR, slowly push the brake pedal to the floor.  Release, repeat, release, repeat, release, repeat (until you get a firm pedal).  This is to let the caliper piston push again the pads completely.

18) Enjoy a nice beverage and toast your work and money saved.

 Original Pads after 70k Miles.  Nice.


*Remember - Front Pads and Rotors wear 2x as fast as the rears.  Don't be surprised to replace the fronts a lot more than the rears!

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    13 Discussions

    vince 09

    6 years ago on Step 3

    In step 4 the last picture do you know what that rental tool is called it looks very useful I really want to buy one. thanks

    2 replies
    Sonata85vince 09

    Reply 6 years ago on Introduction

    hi vince. i'm sure it's called a "brake pad tool kit", or something similiar. do a search on google for it, usually in a red, gray, or black plastic case. i usually rent my from the local auto parts store for a few dollars, which is then refunded when i return it. as mentioned, most older or domestic cars can just be pushed in, but if your piston has grooves or holes cut in it, it most likely needs to be screwed back in using this type of tool. pushing this type back in can absolutely damage the rubber seals!

    vince 09Sonata85

    Reply 6 years ago on Introduction

    awesome thanks man I didn't know if there was a technical name for it or what but I will look around for. I do all of my own mechanic work and some for people around town and that thing looks really handy.


    6 years ago on Step 4

    They make a blue colored stuff you use on the back of the pads when installing called "Brake Quiet" You put a layer on the pad back, let it dry, and then install the pads. I would not recommend any other type of grease, anti-seize, etc. on the backs of pads. It remains 'liquid' and may possibly be transferred to the brake rotor which would have a tendency to mess up the braking effect. Another thing to keep in mind is that once all of your pads are changed out, don't add break fluid between pad changes. As the level drops in the master cylinder, that is an indicator of the brake wear. If the level is low, time to check your brakes (instead of waiting for the grinding noise that will soon be heard) Replace your pads before they're 'gone' saves you having to change out your rotors. Pads that wear completely still won't allow the level of fluid in the master cylinder to drop a dangerously low level. If the level goes below the 'Minimum' mark, you have a leak somewhere. Long before the minimum mark is reached, your brakes will be making enough noise anyway that a deaf person could hear them. This way, you don't have to deal with removing fluid from the system while your compressing the pistons. It's not dangerous to drive around with the brake fluid level low in the master cylinder as long as it doesn't go below the the 'Minimum' mark.
    They also make a tool for the 'turn-in' type calipers that is cube shaped and has pins protruding form all six sides in different configurations to match most of the different manufacturers' designs. It might cost about $10.00 and you use it with a 3/8" drive ratchet.
    With front disc brake calipers, I first remove the master cylinder cap (to make sure the fluid can move easily). Before removing the caliper from the assembled brake, I use a big C-clamp (6") and place the 'fixed end of the clamp on the back side of the caliper. The other end of the C-clamp I slip in to hit the outside break pad. Then I just tighten the clamp until the piston is seated. Take the brakes apart as usual, and your already to put them back together since the piston was already compressed before you even took anything apart. It's quicker than farting around with a caliper that can move around while your trying get your tool in place.


    6 years ago on Introduction

    Nice simple description.
    Just wanted to stress what a couple of you already have mentioned about calippers with built-in parking brake. It is VERY important not to try to "push" these kind of pistons back in! You WILL damage/breake the piston and/or the calipper if you do. These pistons need to be "screwed" back in. (As the parking brake self-adjusts by the piston screwing itself outwards as the pad wears).
    The "special tools" for this job can be purchased for a few bucks at Auto Zone or a similar aftermarket place.(Less than $ 10.- each), both for a clamp made specifically for pushing back the piston, and a tool with many slots/configurations fitting different types of brake pistons (for the screw-type of piston). You'll save in the cost of these tools the first time you use them, and greatly reduce the risk of damaging surfaces and gaskets.


    6 years ago on Introduction

    wow. the first line i wrote says "Hello! This page is devoted to doing the REAR disc brakes on a 2002-2005 Hyundai Sonata, but it’s the same general idea for any disc-brake setup" meaning that the procedure is for the 2002-2005 sonata, but the same general idea can be used for any disc-brake setup" lol. obviously each car will have it's own type of specific hardware, etc - this is just meant for an overview. anytime you work on a car you should be aware enough to chock the wheels, operate the jack safely. this author assumes that if you're going to work on the brakes, you'd have a basic understanding of the setup steps involved.


    6 years ago on Step 4

    One important step missing: When you use the clamp to retract the piston, make sure you open the bleeder valve. Failure to do this will result in rusty dirty brake fluid that was in the caliper body getting pushed back into the reservoir. This is one cause of stuck calipers which will cause extreme overheating. You will then have a really big brake job!

    1 reply

    If your car is well maintained or even remotely new, there should be no rust in your braking system. If there is, a full flush of the brake system needs to be done. Basically, if the brake fluid is not clear, it needs to be replaced.


    6 years ago on Introduction

    This would be almost fine if the title were "How-to: Rear brake job on Hyunday Sonata".

    This title is misleading in that it fails to mention other configurations of parking brakes. All cars with rear disk brakes I own (Mercedes, Citroen and Alfa Romeo) use the calipers as parking brakes instead of having drums inside the discs. Those calipers have both cables and hoses connecting to the master cylinder. Instead of being compressed, such calipers are wound back (on the Alfa Romeo, I use a 12mm Allen key that fits on the caliper cylinder and has to be turned and pushed in at the same time) and compression alone doesn't move the cylinders.

    You failed to mention the importance of securing the other wheels with large wedges before jacking the car.

    Moving and adjuster on a drum brake and the cable adjuster on the lever inside are different things. A drum brake adjuster is an automatic device that takes up slack, preventing the springs on the shoes from retracting the hydraulic piston completely (which would slacken the brakes enormously). The brake cable adjuster is a manual device to compensate slack and stretch of the main cable, a completely different task!
    The adjusters have to move freely. Considering how dirty brake drums usually are, it is wise to inspect the adjusters and replace if necessary. At least, disassemble, clean and lightly coat the threads on the adjusters with copper grease before fitting them again. Before driving take care to pull the parking brake a few times and pump the pedal to make sure the adjusters have taken up the slack, otherwise the parking brake won't be effective.

    This brings me to mention silicone grease is not anti-sieze or high temperature grease. Anti-sieze is usually a copper based grease (that is also good for the temperatures brakes go to). It actually is a grease with a solid lubricant.

    Greasing bolts will protect them from getting stuck due to rust. However, greasing bolts will distort torque readings on any wrench. A shop manual should be consulted to know if bolts go on dry or lubed. Greasing brake bolts however is not such a good idea.

    Modern anaerobic thread lockers are available on any good parts store. These materials solidify on the absence of air only. They act as lubricants when you're tightening the bolts and will hold them in place for a long time. As they fill in the threads, those will never rust on the inside.

    When fitting new pads, always check that brake fluid level isn't too high. Fluid runs back as the calipers are compressed and spills will eat up the paintwork.


    6 years ago on Introduction

    well said everybody, and i appreciate the comments!

    i don't think i ever mentioned unbolting the caliper from the brake line, just from the pad holder. sorry for any confusion. i've used marine-type grease before, and it seems that 30k isn't really enough to differientiate between anti-seize and standard grease. of course, i use a ridiculous amount to keep squeal down so that probably has something to do with it haha.

    some cars do require a special tool, especially hondas and vw's, that are screwed in instead of pushed in. trying to c-clamp those pistons could result in tears in the piston boot, etc.


    6 years ago on Introduction

    Nice write up :-)
    i like to use the old brake-pad and a c-clamp to push that caliper piston back in


    6 years ago on Introduction

    Good instructable. However, anti-seize is not the same grease. Anti-seize is used on nuts and bolts so they can be removed easier, but it is not designed as a friction modifier. A high temperature grease is needed for the caliper pins and pad clips, it is sold as"brake part grease."

    I would also advise against using anti-seize; I know they are a PITA to remove, but most factory service manuals I have seen recommend thread locker blue on break part bolts. If one of those bolts comes loose when driving it will be a much bigger PITA


    6 years ago on Introduction

    Nice pics - easy to follow.

    Save more money:
    1. Use a C-clamp to press in the piston - no need to rent a tool.
    2. No need to disconnect the caliper form the brake line (unless you want to) and thus alleviating a need/time to bleed the brake lines (no need to buy fluid). Just put a brick/block under the jacked up car - near the work area - in a convenient spot to rest the caliper on so the brake line is not stressed. The C-clamp is then used to compress the piston.

    I have done this since the 80's, never had to bleed a brake line, and the job goes fast.