Bedding in OEM Brake Pads on an Aston Martin DB9 or Vantage

Glowing brake rotor on a DB9

One of the most common maintenance items on any car, the DB9 and Vantage included, is servicing your brakes.   When your service includes either changing the brake pads, the brake rotors, or both, it is necessary to properly ‘mate’ the two components together for optimal performance and, in the case of an Aston Martin, to reduce or eliminate brake squeal.

The bedding in process is tackling two things at the same time:

  1. Worn and Uneven Brake Rotor Surface

    It shapes the surface of the pad to match the rotors surface.  If you’d ever looked at the surface of a used brake rotor you will notice that the wear isn’t completely even.  A used rotors surface will have waves and perhaps grooves in it.   If you change just the pads on your Aston without resurfacing or replacing the rotors, the new pads are flat and will only be making contact with the tops of the ridges or waves, significantly reducing the braking friction area and your braking ability.   Bedding in the pads immediately after installation will match these up under more controlled conditions so your brakes are ready when you need them.

  2. There is some science at work.  When you bed your pads in to old or new rotors, it chemically deposits (bakes) some of the pad material onto the surface of the rotor.  The friction coefficient (grippiness) of the pad to rotor increases once this is accomplished, and gives you better braking.
    1. It should be noted that this is one of the conditions that can lead to the annoying brake squealing that Aston Martins are typically vexed with.  Most harder brake pad materials (available on the aftermarket) will reduce brake dust, but are harder to bed in properly (and keep bedded in).

Applies to

This article does NOT cover the awesome Carbon Ceramic CCM option or ANY of the aftermarket parts from Porterfield, EBC or others

Heads Up – READ THIS

Aston Martin has fitted the DB9 and Vantage with a mighty set of steel brakes from Brembo.  This article is NOT covering the even mightier optional Carbon Ceramic (CCM) brakes that were an option on some vehicles (and they have their own bedding in process).

This article ONLY covers the bedding in process for the original brand of brake pads fitted (OEM) that were made by Pagid and sold through your Aston Martin Dealer.  For my 2005 DB9, that is Aston Martin part number 7G43-2D007-AA for the Fronts, and part number 7G43-2C562-AA for the Rears.

If you are fitting aftermarket Pads or Rotors, you should follow the recommendations of the specific manufacturers if they are provided and different.  They would know best.

Specifically this is NOT the correct procedure for aftermarket pads such as Porterfield R4-S (my favorite), the EBC Red Stuff or potentially others.

Since I regularly run Porterfield R4-S street pads for reduced brake dust (rather that the very, very dusty OEM pads made by Pagid), I contacted Porterfield for their specific recommendations for bedding in.   Porterfield R4-S are a more high performance pad for performance ‘Street’ driving, meaning you can use in your daily driver AND on an occasional track day (like me!).  As it turns out the process for the Porterfield’s is completely opposite of the Aston Martin OEM recommendations, and following the Aston Martin recommended process below will actually SPOIL the Porterfield R4-S pads and lead to glazing and brake squeal (I know this first hand now).

Here are two other bedding in procedure articles I have created if you are using these aftermarket pads:

Prerequisites

To get to this point you’ll probably have done either a ‘Pads Only’ or ‘Full Brake Service’.  I have a few videos that might help you with those tasks:

Tools Needed

This one is fun.  You just need:

  • Your Right Foot to go ‘Zoom’ and ‘Screech’
  • Your DB9 or Vantage
  • A quiet stretch of road (a few miles long ideally) where you can accelerate, brake hard, and cruise in between letting them cool without braking again.  I use an ~1 mile long rarely used paved country road near my house.

Procedure

I checked a few resources in preparing to do this.  I started with what Aston Martin has to say.  They cover it in the Official Aston Martin Workshop Manual section 6.03 on Brake Pad Bedding In (read about it here).

They later revised the process due to owner complaints about brake squealing, and released Field Service Bulletin FSB-151 Brake Bedding In Procedure (read the full bulletin here).   This is pretty much the gold standard then for bedding in a Factory OEM set of Pads and Rotors (OEM pads are made by Pagid, and the OEM rotors are made by Brembo).

Tackling this will take about 18 minutes once you’ve reached your quiet piece of road.

  • If you’ve just changed your brakes:
    • Be sure to pump the brake pedal a few time BEFORE you back out of the garage right after the brake pad change.  This will close the gap between the pads and rotors to normal.  You’ll probably notice a ‘long pedal’ on the first pump, and by the 2nd or 3rd the pedal feel and stroke should be normal again.  If it isn’t, DON’T put it into gear until it is.
    • Drive gingerly using light brake pressure to the spot.  Leave lots of space for stopping, remember that your brakes won’t be at the full and normal performance level.
  • You want your brakes to be cool when you start the overall procedure (less than 80 deg C).
  • Be on a quiet stretch of road with no one anywhere near behind you.  You’ll be accelerating and braking erratically, and will freak someone else out if they see you, even from a distance.  Not sure what the police would think either (be sure to obey all the traffic laws as usual ;>)
  • Cycle 1 – the Gentle Start
    • Start by cruising along at 60 mph and then gently decelerate to 20 mph.
      • The official description of ‘gentle’ is 0.3g.  If you have a G meter app on your phone, you can try and do that, but I just used light braking like I would do in normal city traffic.
      • You don’t have to be exactly at 60 or 20, just close.  This is a guideline to make sure we are putting enough energy (heat) into the pads/rotors.  Too fast will overheat, too slow won’t get them up to temp.
      • Do Not Stop completely until this entire process is completed (stop if there is an emergency of course)
        • Why?  If you come to a full stop with smoking hot rotors there is a good chance part of your brake pad material will transfer and bake onto the rotor in just that one spot, and this could cause brake ‘judder’
    • Immediately accelerate normally back to 60 mph (no rush, but don’t doddle)
    • Repeat the procedure again for a second time, braking gently  from 60 mph to 20 mph.
    • Repeat the procedure again for a third time, braking gently from 60 mph to 20 mph.
    • Now accelerate normally back to 60 mph and drive without using the brakes at all for about 2 miles (3 Kms) to allow them to sufficiently ‘cool’.
      • That’s about 2 minutes.
      • Avoid using the brakes entirely during this period, but you can use very light braking if needed.
      • During this time is when some of the chemical science magic is happening.
      • On my 1 mile stretch of road I can coast down slowly and make a U-turn at the ends to accumulate the time/miles.  Its not so much about the exact mileage, it just enough time with cooling RAM flow air going over the brakes when they aren’t in use.
  • Cycle 2 – Moderate braking
    • During this cycle we are going to follow the same procedure three times like before, but this time increase the braking rate to 0.5g’s.  This is braking pretty firmly, but no where near using the anti-lock brakes yet.   Fun driving braking, feels kinda enjoyable to hang in the seat belt some.
    • At 60 mph brake moderately to 20 mph
    • Accelerate normally back to 60 mph
    • Repeat the process a second time
    • Repeat the process a third time
    • Now accelerate normally to 60 mph and drive without using the brakes at all for about 2.5 miles (4 Kms) to allow them to cool.
      • This is about 3 minutes
      • Avoid using the brakes entirely during this period, but you can use very light braking if needed.
  • Cycle 3 – the Fun Stuff – Hard Braking
    • During this cycle we are going to repeat the process yet again, but this time we are going to be doing full anti-lock maximum braking (about 1.0g) right to a complete and full stop each time.
      • Tighten up your seatbelt
      • Don’t have anything loose in the car like your cellphone on the armrest, etc.  It will get thrown about.
      • Be 100% sure there is no traffic behind you
    • At 60 mph maximum brake (anti-lock should be engaging) and come to a complete stop.
    • Immediately accelerate normally back to 60 mph.
    • Repeat the process a second time
    • Repeat the process a third time
    • You should be full of adrenaline (since that was fun and visceral).  With the fun is over now accelerate back to 60 mph and drive without using the brakes at all for about 5 miles (8 Kms) to allow them to sufficiently ‘cool’.
      • That’s about 5 minutes
      • They will be smoking hot at this point, so this is really critical you give them the full cooling time.
      • You can extend the cooling period if needed (while driving home).

That’s it.  With luck the science magic has happened and you brakes should be well mated.  I sure noticed a major difference in brake performance between the start and end of the process in my car.  At the end the brakes felt massively grippy.

Brake dust on rims after bedding in procedure complete

When I got home the evidence of the event was apparent.  My clean rims were now covered in a layer of brake dust generated by the aggressive bedding in process.


Video

I made a short video of the process just outlining the procedure while I did it myself.

[Coming Soon]

2 thoughts on “Bedding in OEM Brake Pads on an Aston Martin DB9 or Vantage

  1. Gaqry Knox

    About those dirty rims. I’d suggest waiting a day to wash/clean them. Then, immediately after cleaning, go for a drive of several blocks with a few moderate stops. Just enough to get the water that was on the rotors and pads warm enough to evaporate off, then with minimum use of the brakes, put the car back in the garage.

    Leaving the rotors/pads wet when in the garage will lead to corrosion of the rotors, and probably some ‘rust’ joining of the pad and rotor where they are in contact.

    Gary

    Like

    1. That’s good advice, keep the water off the rotors right after the bedding in and they are still hot.

      I too have noticed its a bad idea to put the pads away wet after a wash. I do the lap around the block and warm the brakes up to dry them out.

      Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.