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Ford Mustang Rear Brake Pads Replacement Guide
How to change the rear disc brake pads on a sixth generation 2015 to 2022 Ford Mustang (EcoBoost 2.3L I4).

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2019 Mustang Rear Wheel
Slightly Loosen Lug Nuts
Raise Rear of Vehicle
This automotive maintenance tutorial was specifically written to assist owners of the S550 sixth generation 2015, 2016, 2017, 2018, 2019, 2020, 2021 and 2022 Ford Mustang EcoBoost 2.3L I4 model with the standard braking package in changing the rear disc brake pads and lubricating the caliper slider pins. Plus directions for replacing the rear rotors if necessary.

The procedure and torque specifications may be different for other Mustang models with the "Premium" braking package (4 piston front calipers), the "SVT Performance Package" and the "Performance Package" (Brembo 6 piston front calipers).

(The 7th generation S650 Ford Mustang is supposed to be released in 2022 as a 2023 model year vehicle.)

Owners of other Ford and Lincoln vehicles such as the Fusion, Taurus, Escape, EcoSport, Flex, Expedition, Bronco, Ranger, Transit, F-150, C-Max, Fiesta, Focus, Edge, MKZ, Continental, Corsair, Nautilus, Aviator and Navigator may also find these DIY instructions to be helpful.

A few compatible sets of new rear brake pads with their part numbers include the following: Power Stop Z23-1793, Bendix SBC1793, Callahan CPK01156 and Wagner QC1793.

Please verify the correct part numbers for your vehicle by using the Amazon Part Finder website. The compatible replacement brake pads may vary depending on the model year and trim level.

The tools and other items needed to complete this procedure include a lug nut wrench, a floor jack, two jack stands, wheel chocks, a 14mm socket, a 3/8" drive ratchet, a Lisle 28600 disc brake piston tool and a tube of brake caliper grease.

The first few steps are to drive the car on to a level surface, shift the transmission into "Park" and turn off the ignition.

Make sure that the emergency / parking brake is NOT engaged. If the parking brake is set, you will not be able to pull the caliper off the old pads.

Place wheel chocks on both sides of the front tires to help prevent the vehicle from moving.

Slightly loosen the five lug nuts on the rear wheel by turning them about 1/4 to 1/2 turn in the counterclockwise direction with the tire iron.

Carefully raise the rear of the vehicle with the floor jack and securely support it with at least two jack stands. Please do not solely rely on the floor jack to support the car.


Spin Off Five Lug Nuts
5 Lug Nuts Removed
Caliper, Bracket, Rotor
I prefer to only work on one side of the car at a time to keep three tires on the ground for extra safety.

Spin off the five lug nuts in the counterclockwise direction.

Set the lug nuts aside in a safe place.

Carefully pull off the wheel and tire.

Some home mechanics choose to place the wheel below the frame rail of the vehicle as an extra support device just in case the jack stands fail.

Once the wheel has been removed, you'll be able to see the rear caliper, bracket, rotor and suspension.

Rear Brake Caliper
Loosen Bottom Bolt
Loosen Top Bolt
The rear brake caliper is held in place to the bracket by two bolts situated on the back side of the caliper with the bolt heads facing in towards the trunk.

Loosen the bottom caliper bolt by turning it in the clockwise direction (as seen from the outside of the car) with the 14mm socket and a 3/8" drive ratchet.

Then loosen the top caliper bolt by turning it in the clockwise direction (when viewed from the outside of the car as shown in the pictures) with the 14mm socket and a 3/8" drive ratchet.

I had trouble fitting my 14mm socket over the top caliper bolt due to the parking brake mechanism being in the way.

So instead I used a standard 14mm wrench to loosen the top caliper bolt.

Spin Out Lower Bolt
Remove Upper Bolt
Two Bolts Removed
Spin out the two caliper bolts the rest of the way by hand.

Set the two bolts aside in a safe place.

Lift Caliper Off Pads
Screw-In Caliper Piston
Rest On Suspension
Carefully lift the caliper off the old brake pads and out of the bracket.

Rest the caliper on the suspension or suspend it from the spring with a bungee cord or some twine.

Avoid pulling, stressing, kinking or bending the rubber brake fluid hose.

The sixth generation Mustang is equipped with "screw-in" type rear caliper pistons that need to be rotated in the clockwise direction to retract them back.

Do NOT use an "F" clamp to try and compress back the rear caliper pistons like you would for the front pistons.

"V" Shaped Spring Clips
Pull Off Top Clip
Drag Reduction Clip
Carefully pull the "V" or "U" shaped metal spring clips off the outer edge of the old brake pads.

These are the "drag reduction clips", "pad spreader" or "friction reducing clips" that help move the pads away from the rotor when you are not pushing on the brake pedal.

Set the two "V" shaped spring clips aside in a safe place.

Remove Old Inner Pad
Wear Indicator Bar
Remove Old Outer Pad
Pull the old inner and outer brake pads out of the bracket.

Make a mental note of where the wear indicator bar or "squeal bar" is situated on the old brake pads.

On this 2019 Mustang convertible, the wear indicator bar was located at the bottom of the old inner pad.

Pad Abutment Clips
Remove & Replace Clips
Pull Out Caliper Slider Pin
If your new set of rear pads includes a bag of replacement hardware, pull the old pad abutment or "anti-rattle" clips out of the top and bottom of the bracket.

Clean the caliper, rotor, bracket and lug studs with some brake cleaner spray.

Try to avoid breathing in the brake dust or the cleaning spray since they might be carcinogenic.

Apply a thin layer of brake parts lubricant grease to the top and bottom of the pad abutment clips.

Avoid getting grease on the friction surface of the rotor or the new pads.

Push the new pad abutment clips into the top and bottom of the bracket. Make sure the clips are fully seated in place.

Rotor Replacement Instructions

If your Mustang has been exhibiting shuddering, vibrations or shaking in the rear end during braking, the rotors might be warped or worn out and should be replaced.

To replace the rotors, remove the two 18mm bolts on the back side of the bracket that hold it in place to the wheel hub. Set the two 18mm bolts aside in a safe place. Slide the old rotor straight off the wheel hub and lug studs.

If you have trouble removing the old rotor due to corrosion (rust) or debris, try hitting it a few times with a rubber mallet.

A few compatible replacement rear brake rotors with their part numbers are as follows: Bendix PRT6299, DuraGo BR901374 and Callahan CRK15262.

The Ford Mustang service manual mentions that the two caliper bracket bolts (or "brake caliper anchor plate bolts") should be discarded and NOT re-used again. This is due to the bolts "galling" (wearing down due to excessive friction between two moving surfaces that can lead to cold welding and seizing).

The OEM part number for the rear caliper bracket support bolts is -W715623-S439 (also known as part # W715623S439 or W715623 S439).

Slide the new rotor over the lug studs, line up the bracket and spin in the two 18mm bolts.

The 2016 Ford Mustang technical service manual specification for tightening the 18mm caliper bracket bolts is 129 lb-ft (or 175 Nm) of torque.

It would be best to use a torque wrench to properly tighten the bracket bolts.

Double check that the bracket bolts are tight before moving on to the next steps.

Lubricate & Replace Pins
Test Fit Piston Tool
Rotate - Retract Piston
In order for the caliper to operate smoothly, the two caliper slider pins need to be well lubricated.

Do not mix up the top and bottom caliper slider pins since they are slightly different.

Pull out one caliper slider pin at a time, apply a thin layer of brake caliper grease to the smooth parts and push it back into its rubber dust boot.

Repeat the process to lubricate the other pin.

In order for the caliper to fit over the thicker new brake pads, the "screw-in" type piston needs to be retracted back into the caliper.

The easiest way to accomplish this is with a Lisle 28600 disc brake piston tool attached to a short extension bar and a 3/8" drive ratchet.

An alternative method is to use a pair of needle nose pliers to turn the piston. Just try to avoid scratching the piston or damaging the rubber dust boot that surrounds it.

Test fit the various sides of the tool until you find the side that has the best grip on the piston.

Keep in mind that the piston's orientation should look the same when you are done turning it back. The two recessed sections or "notches" must be in the same positions in order to line up with the metal pin or "peg" on the new pads.

Slowly turn the piston in the clockwise direction to retract it back down until it is just about flush with the rubber dust boot that surrounds.

The service manual specifies that you may need to use "moderate to heavy force toward the caliper piston" while rotating it in the clockwise direction.

If the piston is not going straight back in, stop and double check your technique.

Piston - Same Alignment
Wear Bar - Bottom Inner
Install New Outer Pad
As seen in the picture above, the two "notches" in the caliper piston are lined up to allow clearance room for the metal pin on the center of the new inner brake pad.

The wear indicator bar should be situated at the bottom of the inner brake pad.

Insert the new inner and outer brake pads into the bracket.

Push Pads Against Rotor
Re-Attach "V" Spring Clip
Top Pad Spreader Clip
Push the two pads together until they are flush against the rotor.

If your new brake pads are equipped with the small holes on the outer edge for the drag reduction clips, re-attach the "V" shaped spring clips.

Your new pads might include new "V" clips or you'll need to re-install the old ones.

Lower Caliper Over Pads
Spin In Bottom Bolt
Tighten Lower Bolt
Carefully lower the caliper over the new brake pads and into the bracket.

If the caliper won't slide over the new brake pads, you may need to retract the piston a bit further.

Line up the bolts holes in the caliper with their corresponding bolts holes in the caliper slider pins within the bracket.

Spin in the two caliper bolts a few turns by hand in the counterclockwise direction (as seen from the outside of the car) to help prevent them from becoming cross threaded.

Tighten the bolts in the counterclockwise direction (when viewed from the outside of the vehicle) with the 14mm socket and a 3/8" drive ratchet.

Hold Pin With Pliers
Spin In Top Caliper Bolt
Tighten Upper Bolt
If the caliper slider pin turns as you are attempting to tighten the bolt, hold it in place with some pliers or a wrench.

The 2016 Ford Mustang service manual specification for tightening the two 14mm rear caliper bolts is 24 lb-ft (or 32 Nm) of torque.

Caliper Bolts Secured
Rubber Valve Cap
Brake Fluid Bleeder Valve
Double check that the two caliper bolts are tight before moving on to the next steps.

If the brake pedal feels soft or spongy, the brake fluid might contain a few air bubbles or some moisture.

It would be a good idea to bleed the brake lines and flush out the old fluid with fresh new DOT 4 brake fluid.

I highly recommend using the Allstar Performance Bleeder Bottle to bleed the brake lines. It makes this procedure an easy one-person job compared to having an assistant pump the brake pedal for you.

According to the service manual for the 2015 to 2018 Ford Mustang, the brake line bleeding order is as follows: 1. Rear Right (Passenger Side) 2. Rear Left (Driver Side) 3. Front Right (Passenger) and 4. Front Left (Driver).

Most other vehicles have this same brake line bleeding order where you start at the caliper furthest from the master cylinder and work your way towards the brake fluid reservoir and master cylinder.

The brake fluid bleeder valve is located on the top of the caliper just below the upper caliper bolt and it is covered by a rubber cap.

In order to open and close the bleeder valve, you'll need a 10mm wrench.

Make sure that the bracket bolts, caliper bolts and brake fluid bleeder valve are all tight before moving on to the next steps.

Replace Rear Wheel
Spin On Five Lug Nuts
Slightly Tighten Lug Nuts
Push the rear wheel back into place over the lug studs.

Spin on the five lug nuts a few turns by hand in the clockwise direction to make sure they don't become cross threaded.

Slightly tighten the lug nuts with the tire iron by turning them in the clockwise direction in a "star" or "criss-cross" pattern.

I use my foot to hold the rear tire while I slightly tighten the lug nuts.

Lower Car From Stands
Torque Lug Nuts
Rear Brake Job Done
Carefully lower the car from the jack stands by using the floor jack.

Continue tightening the five lug nuts in the clockwise direction in a criss-cross or star pattern with the wrench until they are snug.

The 2019 Ford Mustang owner's manual specification for tightening the lug nuts is 150 lb-ft (or 204 N-m) of torque.

Please double check your owner's manual for the correct lug nut torque specification for your vehicle!

It would be best to use a torque wrench or an electric impact wrench with a 150 lb-ft torque stick to properly tighten the lug nuts.

Check the level in the brake fluid reservoir and if necessary, slowly pour in some new DOT 4 brake fluid until it reaches the "MAX" (maximum) line on the side of the bottle.

Sit in the driver's seat and firmly push down on the brake pedal a few times to restore the brake line pressure.

To break in (or "bed-in") your new standard ceramic or metallic brake pads, just drive normally for the first few hundred miles and try to avoid doing any hard or "panic" stops which might glaze over the new pads and lead to reduced braking performance and / or noisy brakes.

If you installed performance brake pads meant for drag racing, autocrossing or road racing, follow the manufacturer's recommend procedure for breaking-in or "bedding-in" your new pads.

It would also be a good idea to check your parking spot, driveway or garage for drops of fresh brake fluid during the next few days since they might indicate a leak from the reservoir or the bleeder valves.

Don't forget to write down the rear brake job in your vehicle's service records.

For more, please check out all of the 2015-2022 Ford Mustang DIY Repair & Maintenance Guides.

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