How to Change The Brake Pads in Your Car

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Since the brake systems of almost all cars differ, this article should be considered ONLY as a very general guide on how to change your brake pads. Some specialized procedures will not be covered but if you do it correctly, changing your own brake pads is a much cheaper option than taking it to a shop.

Steps

1. 1
   Get the correct brake pads - Pads are available at any auto parts store or your local car dealership. Just let them know the year, make and model of your car. They will typically offer you a choice of different quality pads with a wide range in price. In general, the more expensive they are, the longer they last. Be aware that some very expensive pads with a higher than desirable metal content may be aimed at the 'Rally' market for use with performance Rotors. You will probably not want those because they are likely to cause premature wear of standard Rotors. Preferably try to obtain brake pads that have a visibly similar metal content to the existing pads. Also, some people find that less expensive pads are noisier than "brand name" pads.

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2. Make sure the vehicle is cooled down - If you have recently driven, you may be working with extremely hot pads, calipers and rotors. Be sure that these parts are safe to touch before moving on.
3. 3
   Loosen the lug nuts - Using a lug wrench (one is usually provided along with the car's jack), loosen each of the lug nuts that hold the wheels onto the car about two thirds of the way.
4. 4
   Jack the car up - Locate a safe place to position the car jack under your car. Check the user's manual or check for markings that indicate where to place the jack. Put some chocks behind the wheels that are on the ground to stop the car from rolling forward or back. Carefully jack the car up until the wheel can be removed easily. Place a jack stand or blocks under the frame of the vehicle. Do NOT trust the jack alone. Repeat for the other side of the car so that both sides are securely supported.
5. 5
   Remove the wheels - Finish loosening and removing the lug nuts. Pull the wheel straight out towards you to remove it.
6. 6
   If the wheel rims are Alloy and are either seized or partially seized on the studs, try kicking the tyre at the bottom with your foot a few times and hopefully it will move. when this occurs, you should clean the studs, stud holes, Rotor mounting surface, and the rear mounting surface of the alloy wheel - with a wire brush and apply anti seize compound before refitting the wheel.
7. 7
   You should now be looking at the rotor (a large, flat metal disc) and the caliper (a large clamp-like device wrapped around the top of the rotor).
8. 8
   Remove the caliper bolts - There are many different ways that the caliper is secured and different Caliper designs necessitating different removal procedures. The mounting position also depends on the Caliper design and whether it is an all one piece, a two piece, or a more complex design Caliper. All One piece Calipers are generally secured with between 2 to four bolts at the inside of the stub axle housing. Spray these bolts with WD-40 or PB Penetrating Catalyst to aid in removing them. Using a correct size Socket or Ring spanner, loosen and remove the bolts MAKING ABSOLUTELY SURE THAT THERE ARE NO SHIMS FITTED BETWEEN THE CALIPER MOUNTING BOLTS AND MOUNTING SURFACE. If there are they must be refitted as they were or the Caliper will not sit correctly.
9. 9
   If any do fall out unexpectedly, you will need to refit the Caliper without the brake pads and using a combination of feeler guages, measure the difference between the pad mounting surface to the Caliper at the top and Bottom. Then, work out the difference/s and allocate the shims accordingly.
10. 10
    Alternatively, many Japanese vehicles use a 2 piece sliding Caliper that only requires the removal of 2x forward facing, upper and lower, slider bolts, and NOT the removal of the entire caliper. These bolts are often 12 or 14mm heads.
11. 11
    Additionally, if these caliper are completely removed, it is much more difficult to fit the brake pads into them.
12. 12
    Check the caliper pressure - The caliper should now move a slight amount if you shake it. If not the caliper is under pressure and it may fly off when you remove the bolts. Take extra precaution to not be in its path, whether it is loose or not.
13. 13
    Next, have a piece of light tie wire handy, about a foot long, before you proceed.
14. 14
    As the caliper will still be connected to the brake line, hang it up carefully by the wire, in the wheel well, so that it doesn't drop and have any weight on the flexible brake hose.
15. 15
    Remove the top of the Brake Master cylinder from under the engine hood and inspect the fluid level before the pistons are 'Squeezed' back to enable the new brake pads to be fitted. Many mechanics draw some fluid from the master cylinder before proceding to squeeze the brake Caliper pistons.
16. 16
    However, a better method is bleed the old Caliper fluid off by fitting a brake bleeding hose to the Caliper nipple, place the hose in a small bottle and undo the bleeder nipple as the pistons are squeezed. They are easily squeezed with one hand using large 12 inch water pump pliers - much easier than C or G clamps. So, the pliers are held in one hand and the bleeder spanner in the other. If it was not intended to bleed the brakes they still do not need to be, but the old fluid will have been removed from the Calipers at the same time as squeezing the pistons fully inwards. Repeat this with the other pad. Note that there is normally only one piston to be compressed for the right front and likewise for the left front.
17. 17
    Remove the pads - Note how each brake pad is attached. They typically snap or clip in with attached metal clips. Remove both pads. They may take a little force to pop out, so take care not to damage the caliper or brake line while getting them out.
18. 18
    Put the new pads on - Spread the special anti seize lubricant that came with your pads, (if it's not provided you can get it at any auto store,) sparingly on the metal contact edges and on the back of the pads, the surface of any shims and the piston pad contact area. This will prevent a lot of annoying squeaking. Attach the new pads exactly the way the old ones were attached.
19. 19
    Check the brake fluid - Check your vehicle's brake fluid level and add some if necessary. Replace the brake fluid reservoir cap when finished.
20. 20
    Replace the caliper - Slide the caliper slowly back over the rotor, proceeding easily so as not to damage anything. Replace and tighten the bolts that hold the caliper in place.
21. 21
    Put the wheel back on - Slide the wheel back into place and hand tighten each of the lug nuts snug.
22. 22
    Lower the car - With one side of the car supported by the jack, remove the block or stand on that side and slowly release the jack and to lower the car. Repeat for the other side so that both wheels are back on the ground.
23. 23
    Tighten the lug nuts - Moving in a "star" pattern, tighten one lug nut, then one across from it until each nut is fully tightened to torque specification.
24. 24
    See technical info to find the torque spec for your vehicle. This will insure the lugs have been tightened enough to prevent the wheel coming off or overtightening.
25. 25
    Start the vehicle - Making sure the vehicle is in neutral or park, pump the brakes 15 to 20 times to insure proper seating. Push the brake pedal and put the vehicle in gear if it rolls more than a foot put the vehicle into park.
26. 26
    Test your new brake pads and installation - Going no more than 5 MPH on a quiet residential street, brake like normal. If the vehicle seems to stopping normally, repeat the test and go up to 10 MPH. Repeat several more times, gradually going up to 35 or 40 MPH. You can also go 5 MPH in reverse and brake. These braking tests ensure there are no issues with your brake-pad installation, gives you confidence when driving on main streets and helps "seat" the brake pads into place.
27. 27
    Listen for problems - When testing, if you should hear a grinding sound such as metal on metal, you probably have the brake pads reversed (i.e., the inside surface incorrectly facing out). This should be corrected immediately. Note that the new brake pads may squeak a little bit until they are completely broken in.
28. 28
    Celebrate - If all has gone to plan, enjoy your new pads. If not, troubleshoot where the problem is and see where you might have gone wrong.

    
    

Video

Tips

• Use jack stands! This will save you a major headache and money by preventing your vehicle from falling onto the ground.
• You'll need to get a caliper clamp or large C-clamp.
• If you are servicing the rear brakes be careful around the parking brake system; find the proper way to remove and adjust.
• Inspect your rotors if they are shiny or are not flat. These two symptoms may cause the brakes to squeal. If this were to happen, the rotors can be resurfaced flat as long as they stay above the minimum thickness.
• Always measure the thickness of the rotor-- if it is below specification then replace it.
• NEVER TRUST JUST A JACK BY ITSELF!!!! When removing the lug nuts and applying heavy torque, the vehicle can easily roll forward (or backward) an inch or two, causing the vehicle to come off the jack and land on the oil pan, the transmission pan, or a person under the car, etc. Snugly placing 3 or 4 or 5 heavy-duty bricks under the frame of the car (close to where the jack is) is strongly recommended as a safety precaution. In addition, NEVER lay under a car that is only supported by a jack for the same reason noted here!!!! This is especially true if the vehicle is jacked up on a slightly sloping surface. Ensure the other three tires are chocked on the front and back sides with bricks or large blocks of wood.
• Consider turning the vehicle's steering wheel so the front wheel being focused on points outward in the front (after the front tire has been removed). This can make working on a front-wheel caliper assembly much easier because of improved access (after the front tire has been removed). By doing this, both sides of the front caliper assembly are much more exposed and accessible, including the inner side which is usually where the bolts are located which holds the caliper assembly in place. If you use this tip, however, be very careful that you do not alter the way the vehicle is positioned or how the weight is distributed (such as on a slightly inclined surface) which could result in the vehicle slipping off the jack. This tip can prove to be very helpful in getting the front brake-pad replacement job completed and can actually make the job much safer because a person does not have to extend his/her body under the front of the vehicle nearly as much (if at all). However, just be extremely careful when you turn the steering wheel. Do it gradually & ensure no one is under the vehicle when the steering wheel is turned!!!! Closely follow the other safety precautions outlined above concerning the use of a jack when lifting a vehicle. Safety in each step of the process should ALWAYS be of paramount concern!
• Sometimes one or both bolts holding the caliper brake assembly in place can be very hard to loosen. This is usually the result of road grime encrusted around the bolt or the result of the previous mechanic or factory worker overtightening a bolt. To help loosen a very tight bolt, buy a spray can of bolt loosener which is typically sold at an auto parts store. Cost is usually around $2. Liberally spray the bolt & wait a few seconds. Repeat this multiple times if needed. If the bolt is extremely stubborn, spray it, then put the wrench on the bolt & mildly tap the end of the wrench handle over and over with a hammer in the direction to remove the bolt. This vibration causes the bolt loosener chemical to seep in around the threads. This may need to be repeated several times over the course of 5 to 15 minutes (or more) if a bolt proves to be extremely stubborn.
• Propel your brake style into the expert and bleed your brake system while you are down there. Gunk (metal shavings, debris, etc) collects at the ends of your brake lines. This decreases braking strength and can add wear to your calipers. Study this process online, and try to get how-to's for your specific vehicle. If you can follow basic instructions and do your own brake jobs, you can bleed your brakes. The following instructions part is more important when bleeding.
• Have a friend on hand who knows how to do brakes. You may find yourself lost and with your only means of transportation not back together.

Warnings

• Use jack stands! This cannot be stressed enough. Do not trust a jack.
• Do not remove the brake line from the caliper this will cause air to enter the lines and make a mess of things.
• This is a general guide and not a exact plan for every vehicle as with everything else in life if something doesn't look right or you don't know what to do, ask someone who works on vehicles.

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