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How to replace front rotors -

59K views 28 replies 16 participants last post by  TmanInTexas  
#1 ·
I replaced the front rotors on my 2009 Enclave this weekend. I did a search on this forum and did not find a write-up on how to do it, so I thought I would do a quick description on how I did it.

The total job took less than 2 hours, start to finish, including replacing the pads, two test drives and throwing the ball for my annoying golden retriever :blob:. It was really easy - I was quoted $485 from a local shop. Doing it myself, the parts cost $150 ($165 - $15 rebate) including two new rotors, Wearever Gold ceramic pads (lifetime warranty), a quart of synthetic brake fluid, and a can of brake cleaner. There may be other ways of doing this, but the process I followed was:

1) Jack up the front of the car and support on jack stands. Also chock the rear wheels for safety.
2) Remove front wheel. I used a 13/16 socket and ratchet and the OEM jack. If you use the Lug wrench supplied with the car you will be there all day jacking the car up.
3) Loosen upper Caliper guide pin bolt and remove lower caliper pin bolt. The part of the caliper that holds the pads will swing freely up.
4) Remove upper and lower Caliper bracket bolts (requires a 7/8 socket and a TON of torque) and clean the old 'lock tight' from the bolt
5) Hang Caliper assemble on the strut spring. I used a wire coat hanger.
6) Remove rotor set screw using a T-30 Torx bit.

At this point the rotor will slide right off.

7) Clean the new rotor with brake cleaner and install it, re-securing with the rotor set screw.
8 ) Using a brake piston compression tool ($8 at most auto parts stores), compress both brake pistons all the way in. Protect the piston by using the old brake pad between the compression tool and the piston.
9) Install the new pads in the caliper pad bracket
10) Swing the caliper pad bracket back onto the caliper assembly and hand tighten the guide pin bolt
11) Put lock tight on the Caliper bracket bolts and bolt the entire caliper assembly bracket back into place. Torque to 129 Lb Ft.
12 ) Torque the Caliper guide bolts to 30lb ft.
13) Put the wheel back on
13) Torque the lug nuts to 140 lb ft

Test drive. Be sure to pump the brake before putting the car into gear to put the caliper pistons back into place. If you don't feel any vibrations, pulsations or brake fade - do the other side!

After I finished with the rotors and pads, I also bled the brakes (all four wheels of course). It probably wasn't necessary, but as long as I was working on the brakes, I figured I may as well replace the fluid. I did not use a bleeding tool (suction pump) as I have heard bad things about messing up the antilock system. I don't know if that is just an old wife's tale, but doing it the old fashion way is safe and easy.
 
#2 ·
I'll throw in that after the installation, you should perform a "bed-in" procedure:

http://www.stoptech.com/technical-support/technical-white-papers/bed-in-theory-definitions-and-procedures/stock-brake-system-bed-in

For a typical performance brake system using street-performance pads, a series of ten partial braking events, from 60mph down to 10mph, will typically raise the temperature of the brake components sufficiently to be considered one bed-in set. Each of the ten partial braking events should achieve moderate-to-high deceleration (about 80 to 90% of the deceleration required to lock up the brakes and/or to engage the ABS), and they should be made one after the other, without allowing the brakes to cool in between.

Depending on the make-up of the pad material, the brake friction will seem to gain slightly in performance, and will then lose or fade somewhat by around the fifth stop (also about the time that a friction smell will be detectable in the passenger compartment). This does not indicate that the brakes are bedded-in. This phenomenon is known as a green fade, as it is characteristic of immature or ‘green' pads, in which the resins still need to be driven out of the pad material, at the point where the pads meet the rotors. In this circumstance, the upper temperature limit of the friction material will not yet have been reached.

As when bedding-in any set of brakes, care should be taken regarding the longer stopping distance necessary with incompletely bedded pads. This first set of stops in the bed-in process is only complete when all ten stops have been performed - not before. The system should then be allowed to cool, by driving the vehicle at the highest safe speed for the circumstances, without bringing it to a complete stop with the brakes still applied. After cooling the vehicle, a second set of ten partial braking events should be performed, followed by another cooling exercise. In some situations, a third set is beneficial, but two are normally sufficient.


I do this procedure when I install new pads, regardless if they say "no bed-in required", and have had good success. Use a low-travelled, country road, where you can get down to 5 mph and then accelerate back to 55-60 mph several times, and try not to have a complete stop in between.
 
#4 ·
THIS IS GOOD STUFF - THANKS SO MUCH!!!!!

I monitored the forum for my 2002 Toyota Avalon. At 95k miles - engine code said I had a defective heater in my oxygen sensor. I figured out how to test the bad sensor with a multi-meter, and in stall a new sensor. I checked out the other three, and posted a procedure on the Avalon Forum. Last time I looked - my entry had 45,000 hits!!!!!

net net ---- I wish we had more "HOW TO REPAIR PROCEDURES" posted on this forum. Great stuff for us do-it yourselfers..... Wonder if someone could post a procedure on how to change the rear rotors/pads on the Enclave. Suspect with the emergency brake mechanism, it's a little more complicated.
 
#6 ·
rbarrios said:
did you have an assistant pump and hold the brakes for you? since you didnt use a kit?
Correct. I ran a hose from the bleeder screw on the caliper into a jar with a little clean brake fluid in it. My assistant (13 yr/old son) pressed the brake while I opened the bleeder screw. Once fully depressed, I closed the screw and he let the pedal back up. He then topped off the master cylinder and we repeated until the fluid coming out was clean.
 
#7 ·
So you didn't have to remove the large nut on the center of the wheel hub? Or is that the one that the T30 is used for?
 
#8 ·
sklunk said:
So you didn't have to remove the large nut on the center of the wheel hub? Or is that the one that the T30 is used for?
Correct. The axle nut for the hub & bearing assembly is not disturbed during front rotor replacement. The T30 is for the rotor set screw, whose primary purpose was for use during vehicle assembly at the factory, however, installing it after replacing with a new rotor will keep the new rotor fixed to the hub, allowing you to install the pads and caliper easier.
 
#9 ·
I am very glad to see that you followed the proper torque values and torqued all of the bolts that required it.

The one thing I failed to see mentioned was the caliper "slide" pins being cleaned and re-greased. I never had to take the calipers off our Traverse when we owned it, but I would think the calipers still use the slides?

Not making sure they are cleaned and greased properly, can lead to the calipers sticking or applying pressure unequally, causing uneven wear on the new pads.
 
#10 ·
XRDreamliner said:
I'll throw in that after the installation, you should perform a "bed-in" procedure:

http://www.stoptech.com/technical-support/technical-white-papers/bed-in-theory-definitions-and-procedures/stock-brake-system-bed-in

For a typical performance brake system using street-performance pads, a series of ten partial braking events, from 60mph down to 10mph, will typically raise the temperature of the brake components sufficiently to be considered one bed-in set. Each of the ten partial braking events should achieve moderate-to-high deceleration (about 80 to 90% of the deceleration required to lock up the brakes and/or to engage the ABS), and they should be made one after the other, without allowing the brakes to cool in between.

Depending on the make-up of the pad material, the brake friction will seem to gain slightly in performance, and will then lose or fade somewhat by around the fifth stop (also about the time that a friction smell will be detectable in the passenger compartment). This does not indicate that the brakes are bedded-in. This phenomenon is known as a green fade, as it is characteristic of immature or ‘green' pads, in which the resins still need to be driven out of the pad material, at the point where the pads meet the rotors. In this circumstance, the upper temperature limit of the friction material will not yet have been reached.

As when bedding-in any set of brakes, care should be taken regarding the longer stopping distance necessary with incompletely bedded pads. This first set of stops in the bed-in process is only complete when all ten stops have been performed - not before. The system should then be allowed to cool, by driving the vehicle at the highest safe speed for the circumstances, without bringing it to a complete stop with the brakes still applied. After cooling the vehicle, a second set of ten partial braking events should be performed, followed by another cooling exercise. In some situations, a third set is beneficial, but two are normally sufficient.


I do this procedure when I install new pads, regardless if they say "no bed-in required", and have had good success. Use a low-travelled, country road, where you can get down to 5 mph and then accelerate back to 55-60 mph several times, and try not to have a complete stop in between.
It's not that I disagree with you, but do you really think that they do that at the factory?
Have you ever heard of a brake shop telling a customer to Bed the Brakes?
Do you think any brake shop would bed the brakes for a customer?
Do you think that a GM dealer would do at least 2 sets of bed-ins?

Again I don't think it's a bad idea to do bed-ins, however why is it that you never hear about bed-ins except from do it yourselfers?

I can't envision very many women doing this either (no offense). It's just that for most, it would not be their cup of tea.

Also have you ever heard of anyone changing their pads, not bedding-in and then having an accident because of that?

In most owners manuals don't they say no hard stops for the first XXX miles?

Yes, doing it will more that likely make them last longer and grip better, but I don't think that many people do it, and most carry on without doing it. :facepalm:
 
#12 ·
GoldEnclave said:
XRDreamliner, could you please elaborate on the benefits of "bedding-in" new brakes and rotors? Thanks.
Bedding in brakes simply means the pad material is transferred to the rotor surface at a controlled rate to form a thin layer, thus giving you two nicely high coefficient of friction surfaces to rub against during braking. Also, by heating both surfaces up in a controlled manner to their highest working temperature, you lessen the chance later when you have a high force event (sudden stop down a mountain pass) of not depositing brake pad material suddenly to the rotor surface. You'd then get a high spot and bingo! Your brakes act like their warped.

Here's a longer explanation, if anyone cares to read:

Pad and Rotor Bed-In Theory, Definitions and Procedures - Removing the Mystery from Brake Pad Bed-In

In order for any brake system to work optimally, the rotors and pads must be properly bedded-in, period. This process can also be called break-in, conditioning, or burnishing, but whatever terminology you choose, getting the brakes properly bedded-in and keeping them that way is critical to the peak performance of the entire brake system.
However, understanding why the rotors and pads need to be bedded-in is just as important as the actual process. If one understands what is happening during the bed-in process, they can tailor the process to specific pads, rotors, and/or driving conditions. For this reason, we present this generic bed-in overview pertaining to all brake systems, but follow with links to application-specific bed-in procedures to fit most every set of circumstances.

What is brake pad “bed-in” anyway?

Simply stated, bed-in is the process of depositing an even layer of brake pad material, or transfer layer, on the rubbing surface of the rotor disc. That's it. End of discussion. Ok, not really, but although bed-in is quite basic in definition, achieving this condition in practice can be quite a challenge, and the ramifications of improper or incomplete bed-in can be quite a-a-n-n-o-o-y-y-i-i-n-n-g-g.

Abrasive friction and adherent friction

There are two basic types of brake pad friction mechanisms: abrasive friction and adherent friction. In general, all pads display a bit of each, with abrasive mechanisms dominating the lower temperature ranges while adherent mechanisms come more into play as pad temperature increases. Both mechanisms allow for friction or the conversion of Kinetic energy to Thermal energy, which is the function of a brake system, by the breaking of molecular bonds in vastly different ways.

The abrasive mechanism generates friction or energy conversion by the mechanical rubbing of the brake pad material directly on the rotor disc. In a crystalline sense, the weaker of the bonds in the two different materials is broken. This obviously results in mechanical wear of both the pad and the rotor. Consequently, both pads and rotors are replaced when they are physically worn to their limit and are too thin to endure further service.

The adherent mechanism is altogether different. In an adherent system, a thin layer of brake pad material actually transfers and sticks (adheres) on to the rotor face. The layer of pad material, once evenly established on the rotor, is what actually rubs on the brake pad. The bonds that are broken, for the conversion of Kinetic to Thermal energy, are formed instantaneously before being broken again. It is this brake pad-on-transferred brake pad material interaction on a molecular level that yields the conversion process.

With the adherent mechanism there is much reduced rotor wear as compared to abrasive mechanism, but it's not a free lunch – pads now become the primary wear element in the braking system. And even though rotors are not mechanically worn down with adherent systems, they still will need to be replaced on a regular basis.

The all-important transfer layer

As stated above, the objective of the bed-in process is to deposit an even layer of brake pad material, or transfer layer, on the rubbing surface of the rotor disc. Note the emphasis on the word even, as uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration. Let's say that again, just so there is no misunderstanding. Uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.

It only takes a small amount of thickness variation, or TV, in the transfer layer (we're only talking a few ten thousandths of an inch here) to initiate brake vibration. While the impact of an uneven transfer layer is almost imperceptible at first, as the pad starts riding the high and low spots, more and more TV will be naturally generated until the vibration is much more evident. With prolonged exposure, the high spots can become hot spots and can actually change the metallurgy of the rotor in those areas, creating “hard” spots in the rotor face that are virtually impossible to remove.

Bedding fundamentals

In general, bed-in consists of heating a brake system to its adherent temperature to allow the formation of a transfer layer. The brake system is then allowed to cool without coming to rest, resulting in an even transfer layer deposition around the rotor circumference. This procedure is typically repeated two or three times in order to ensure that the entire rotor face is evenly covered with brake pad material. Sounds easy, right? Well, it can be if you have the proper information.

Because the adherent temperature range for brake pads varies widely (typically 100°F-600°F for street pads), each bed-in needs to be application-specific. One could try to generate a one-size-fits-all procedure, but too little heat during bed-in keeps the material from transferring to the rotor face while overheating the system can generate uneven pad deposits due to the material breaking down and splotching (that's a technical term) on to the rotor face.

In summary, the key to a successful bed-in is to bring the pads up to their adherent operating temperature in a controlled manner and keep them there long enough to start the pad material transfer process.
 
#13 ·
ICU said:
It's not that I disagree with you, but do you really think that they do that at the factory?
Have you ever heard of a brake shop telling a customer to Bed the Brakes?
Do you think any brake shop would bed the brakes for a customer?
Do you think that a GM dealer would do at least 2 sets of bed-ins?

Again I don't think it's a bad idea to do bed-ins, however why is it that you never hear about bed-ins except from do it yourselfers?

I can't envision very many women doing this either (no offense). It's just that for most, it would not be their cup of tea.

Also have you ever heard of anyone changing their pads, not bedding-in and then having an accident because of that?

In most owners manuals don't they say no hard stops for the first XXX miles?

Yes, doing it will more that likely make them last longer and grip better, but I don't think that many people do it, and most carry on without doing it. :facepalm:
Yeah, most won't do it... but they're giving away free braking performance. And that's why I bring it up - if you want your brakes to be at their optimal state, bed them in. If not, at least I told you how, and that's the point of these forums - learning from other's experience. :cheers:
 
#16 ·
awyeahr1 said:
is procedure 4 replacing rear discs and pad the same?? thanx.
Very similar. It is very easy to do a pad replacement, you will spend more time jacking the car and removing the wheels than to do the actual brake work.

For another data point: Sunday, I reworked the brakes on my wife's Enclave. 2009 model, 68,000 miles, first brake work since new. I purchased new pads, Wearever Gold ceramic (~$45 front, $35 rear) with the intention of simply "relining" the brakes. After closer inspection with the wheels off, rotors showed quite a bit of wear. Was not comfortable with putting new pads on those rotors so I pulled them off, resurfaced and trued the runout on my lathe. Didn't find the brake rotors to be of inferior quality in any way. It took mimimal facing to clean up rust and ridges and get a nice flat, shiny "like new" surface. My expectation is the brakes are ready for another 60k miles of service.

The biggest issue I had was removing the brake rotors. Stuck in place from 4 yrs of Michigan driving. The front took quite a bit of effort and the rear was even more difficult to remove. If fact, that's how I got here, looking for tips on how to remove stuck rotors. My solution was to use the screw hole for the 8mm TORX screw. While the TORX screw has metric threads, the hole in the rotor is tapped with a SAE 3/8" thread. Intalled a metric set screw in the 8mm hole and screwed a 3/8" bolt into the rotor. When threaded in and tightened against the set set screw, the 3/8 bolt pushes the rotor off the axle flange. Once the rust bond is broken, the rotor is easy to remove. I would not try this without filling the 8mm hole with a set screw because the 3/8 bolt may damage the hole for metric threads and you won't be able to re-install the TORX screw.
 
#17 ·
If you are using the Akebono ACT1169A ProACT Ultra-Premium Ceramic Brake Pad Set, front or rear, they say that brake pads require no break-in.

Product Features
Ultimate upgrade for OE semi-metallic, organic and low-metallic brake pads
Ultra-Quiet - controls noise, vibration and harshness levels
Superior initial effectiveness with no required break-in period
Extremely rotor friendly for longer rotor life
Vehicle optimized ceramic formula for superior performance

Just putting it out there so people don't worry them self to death over nothing.
 
#18 ·
The rotors on my cars tend to get "warped" and need turning after only about 20,000 miles of driving. Unfortunately, my commute involves mostly high speed stop-and-go driving and my rotors take a beating. Also, with the addition of red light cameras, hard stops are becoming more common. Will these "rotor friendly" brake pads help with this issue, too?
 
#19 ·
GoldEnclave said:
The rotors on my cars tend to get "warped" and need turning after only about 20,000 miles of driving. Unfortunately, my commute involves mostly high speed stop-and-go driving and my rotors take a beating. Also, with the addition of red light cameras, hard stops are becoming more common. Will these "rotor friendly" brake pads help with this issue, too?
Warped or chattering? Chattering is often confused for being warped, and is exactly why you want to bed the pads. Chattering is caused by an uneven build up of the pad material that gets embedded on the rotor.

If the pads are bedded and you end up in the driving condition you're talking about with high speed stop and go, you will likely end up w/ uneven build up. After that fast COMPLETE stop that got your pad heated up, and then you don't go, the pad sits on one place and more material is built on and baked onto the rotor in that spot.

This is why the owners manual says don't do this type of driving in the first 500mi of new brakes. It will do natural bedding over that time, and you don't need to worry future hot stops causing a build up. But in your situation, that doesn't sound realistic. So bedding the pads would be the best thing to do.

I'd recommend doing this if you understand what you're doing, why you're doing it, and follow the directions fully. If you don't, then GM's recommendation of not doing any hard stopping for 500mi is the next best thing.
 
#20 ·
I typed "warped" because that is what most folks state when they really mean uneven pad material build up on the rotors. From my understanding, true rotor warpage is quite rare.

Whenever I come to a hard stop, I do try to roll forward a bit after the stop to prevent rotor chattering, but that is not always possible, especially when I am already a bit over the white stop line because I don't want to trigger the red light camera. I have found the chattering issue to crop up usually only after several hard stops by the time I've amassed about 20,000 miles on the new pads/rotors. It is not occurring when the pads/rotors are new.
 
#22 ·
enclavetmudd said:
Does anyone know where Neil would have found the torque specs...I believe him I was just curious?
Torque specifications are listed in the service manual for the specific model. I have an online subscription to the Traverse/Enclave/Acadia/Outlook service manual. It has just about any torque value you would need for most repairs.
 
#23 ·
Just got done replacing my rotors and pads. Total job was about 1.5 hours (I have done pad replacements before). Thank you Neil for the straight forward instructions as well as the torque specs, they were very helpful and made the job a breeze.

For me, I believe my rotors were warped a little as we would get an annoying rotational grind on slow stops...noise is gone now...my pads had plenty of life in them (we have 48k miles) but since I had already bought them and I was already in it all I figured I would replace them anyway.

Thank you again, great information and very easy to do! :cheers: