A Bit About Braking

DISCLAIMER

The information provided here is for general guidance purposes only. It is a combination of manufacturer guidance, first- and second-hand experience, and personal opinion. It may me inaccurate, incomplete, or outdated.


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One of the most common things I discuss with people regarding their Aston Martins is the braking. More specifically, I get asked constantly about what they can do about squealing brakes (and, to a lesser extent, reduction of brake dust). It’s such a common complaint from owners that it’s worth writing an Article about the topic, so, here goes…

Note: Braking is a massive topic and I’m not going to get into it too in-depth here. This Article is just to address the common complaints from Aston Martin owners specifically. I have a lot more information about Aston Martin braking systems on my Information page about them, so check there for more. Meanwhile, this Article will be kept short and to the point.

For a quick Buyer’s Guide for the various brake pads I sell, check out the Brake Pads section of the Info page.

Bottom Line Up Front

Yes, it’s extremely common for Aston Martin brake pads to squeal. This is due to their design.

Usually a dealership will not be able to fix this issue because they’ll replace squeal-prone brake pads with the same type.

If you want to get rid of brake squeal, you will probably either need to get aftermarket brake pads or drive the car much harder to keep the factory brake pads in the higher performance situations that they’re designed to handle.

Brake squeal can be caused by things other than the pads. Check my list of potential causes for more information. This Article is just about brake pads.

This Article is simplified to make it easier to digest. Braking and braking systems is a far bigger topic than what I’ll be covering here.

The Common Complaints

The OEM pads are actually quite good for what they’re designed to do - they have good initial bite, good modulation, good wear characteristics. It’s just that they squeal so damn badly and this is by far the most common complaint about the brakes from Aston Martin owners. It’s annoying, it’s embarrassing, and for most people, it’s actually unnecessary. Couple that with the relatively high amount of dust created by the factory brake pads and you get a brake pad that bothers the majority of owners who also don’t ever experience the benefits of those pads. Basically, the squeal and dust are byproducts of the pads being designed for high performance, but many Aston owners don’t drive their cars hard enough for the high performance thresholds to matter.

When Aston Martin (or any manufacturer) designs a car, they need to make sure all components are appropriate for that car. In Aston’s case, their cars are designed to go really, really fast, so they need braking systems that can manage to control that speed. This means braking systems are used that are designed for high performance more than anything else. Of primary concern the ability of the brakes to repeatedly stop the car from those high speeds, and things like squeal and dust are of less importance.

Another thing worth mentioning is the “chirping” sound people sometimes experience at very low speeds, like in a parking lot. It sometimes sounds like it’s coming from the front of the car, but it’s actually coming from the handbrakes at the rear.

I guess cost could also be listed here since OEM pads are rather expensive, but that falls in line with quite a few other things so it’s no different with brake pads. The simple thing here is that aftermarket brake pads are almost always less expensive. Brake pads for CCM rotors are incredibly expensive, even aftermarket, but at least the ones I sell in my Online Store bring the cost down.

The Root Cause of the Complaints

The brake systems for the early DB9 and V8 Vantage used 4-piston calipers with 355mm rotors in the front and 4-piston calipers with 330mm rotors in the rear. These were decently sized back in the early 2000s for the V8 Vantage but where also used on the roughly 300-lbs (136-kgs) heavier DB9. The V8 Vantage was lighter but expected to be driven a bit more aggressively due to its sporty nature. The DB9 was more of a cruiser but had more weight to bring to a stop. Aston Martin used the same brakes for both since the use cases somewhat evened out the braking needs between the two models - and sharing components between them also help cut costs quite a bit for development, parts supply, and production.

To maximize the braking performance for both the DB9 and V8 Vantage, the brake pads were made without chamfering. This maintains the surface area of the brake pad friction material, which improves braking performance compared to chamfered pads, but it also creates the potential for brake squeal.

A quick example to help demonstrate this: Imagine having a pencil and piece of paper. If you set the pencil perpendicular to the paper so its eraser top is flat against the paper, then drag it, it won’t move smoothly - it’ll grip, bind the paper, and skit along with jerky movement. If you hold the pencil so the eraser’s angle is slightly angled, it won’t do that - it’ll slide smoothly across the paper as you drag it. The same holds true if you use a block-style eraser with an angled edge. The issue is that the perpendicular contact doesn’t allow for smooth flow. Taking that concept to car brakes, the issue is the same. Because we’re talking about two extremely strong items and far greater pressure than an eraser and paper, the results are a little different - rather than binding and tearing the paper, the brake pads will vibrate in the calipers. That vibration causes squeal.

Chamfering may seem like a “no brainer” given the benefits, but look at the picture below and you’ll see how much difference there is in surface area between chamfered and unchamfered pads. The loss of surface area is actually a drawback because it reduces braking potential.

Granted, the chamfering on the pad on the right (a used Porterfield R4-S) is pretty aggressive as this pad is made with normal street driving in mind. The pad on the left (a new Porterfield R4) is made without chamfering because it’s a track/race pad that needs as much performance as possible, so maximum surface area is maintained.

The friction compound used for the pads can also contribute to brake squeal, so some pads will be more prone to it than others, even if they’re chamfered. To further compound this, a brake pad may become more prone to squeal if used with a set of rotors that had been used with another type of pads previously (bedding can help reduce this).

Along with the noise comes the dust - it’s a byproduct of compounds more than anything. The difference in causes is that the dust is more related to the compound that’s used for the friction material rather than the combination of factors that cause brake squeal.

How to Fix Things (or at least mitigate them)

Let’s get dealerships out of the way real quick before we go over real solutions.

Dealership technicians are trained and instructed to use factory-specified parts and methods to fix problems. If a customer complains about squealing brake pads, the dealership will try to sort it using some procedures that could fix or at least temporarily relieve the issue. If that fails, they’ll treat it as a warranty claim and replace them with new ones. However, they’ll replace the squeal-prone brake pads with new brake pads of the same type, which means the new ones will also be prone to squealing.

If you want to keep the factory pads, you can chamfer them to remove the right-angle contact of the brake pads against the brake rotors. This creates a smooth transition as the pads come into contact with the rotors and will reduce the tendency of the factory pads to squeal.

As for other pad options….

The bottom line is that there may not be a “perfect” solution for some people because braking systems function as a series of compromises. This applies to any brake pads - factory or aftermarket. It’s like the old saying, “Pick two: cheap, fast, or reliable.” In this case, it’s more like, “Pick two: high performance, quiet and little dust, or safe.”

  • You can use street pads that are dust-free and silent for high-performance driving, but they probably won’t be safe because they weren’t designed to handle repeated heavy braking.

  • You can use quiet pads with low dust for normal street driving and it’d be perfectly safe since they’re designed for that purpose, but they wouldn’t be able to handle high-performance driving that pushes them past their intended thresholds.

  • You can use high performance pads and they’ll likely be safe for street use, but they probably won’t be quiet or dust free. (This is why the Aston community complains.)

Basically, choosing brake pads is a matter of compromise between how hard you want (or need) to push the brakes, and everything else. Since proper brake pad selection is absolutely critical for safety, intended use should be your first consideration and all else should be secondary. As a general rule of thumb, the more performance-oriented a pad is, the more dust it will have and the more likely it will squeal. There are some variations that prevent that from being a perfect sliding scale which is why I say it’s just rule of thumb.

I carry a small selection of brake pads in my Online Store. These are pads that I’ve tested and approved. Pads I’ve tested and didn’t like aren’t listed, nor do I sell them. If they aren’t good enough for me, why would I try to sell them to other people?

Early DB9 and V8 Vantage

Having tested a variety of brake pads over the years, I came up with three easy options for the early DB9 and V8 Vantage:

  • Porterfield R4-S for street driving

  • Hawk HPS 5.0 for mixed street/track use

  • Porterfield R4 for track/race use

I wanted to keep things simple so people wouldn’t be overwhelmed with options, instead sticking with tried-and-true pads that each served a different purpose.

Later DB9 and V8 Vantage

In 2013, the DB9 got an overhaul that basically amounted to it being a DBS in a Virage body. Included with that was the DBS’s brake system with CCM rotors so the above-listed Porterfield and Hawk pads wouldn’t be suitable. However, I have Pagid RSC1 pads in my Online Store that will do the trick - I have them custom-spec’d with chamfering to reduce squeal.

The V8 Vantage S introduced larger 6-piston calipers with 380mm rotors in the front, with a likewise much larger front brake pad. In early 2012, the standard V8 Vantage got the same front brakes (but with lower cost rotors rather than the pricey 2-piece ones of the V8 Vantage S). The picture below shows the 6-piston front pad (top) compared to the earlier 4-piston front pad (bottom) that it replaced (both are new Porterfield R4-S pads).

Because the front brakes are so much larger on the later V8 Vantage, the pads don’t have to be as aggressive to get the same results. So we can take our options for the earlier cars and tweak them:

  • Porterfield R4-S for street and occasional track use

  • Hawk HPS 5.0 for aggressive street and track use

While I warn people that the R4-S is absolutely not okay for the earlier V8 Vantage for track use (yes, I tested it), it’s fine for track use on the later cars with the larger from brakes. This was first proven to me by my buddy Dan, who posted a super-quick time in his V8 Vantage S around Lime Rock with me holding on in his passenger seat.

2nd Century Cars (DB11 and Vantage)

Some of my customers have complained to me that the brakes of the DB11 and “New” Vantage with iron brakes are too grabby in normal driving, especially stop-and-go traffic. Although the rotors are different sizes than what had come before - the fronts are 20mm larger than the previous generation’s 380mm rotors - the pad shapes are the same as others that had been used before. The front pads of the later V8 Vantage can carry over to the fronts of the DB11 and New Vantage. The front pads of the earlier V8 Vantage can carry over to the rears of the DB11 and New Vantage.

The same recommendations also carry over to the 2nd Century cars:

  • Porterfield R4-S for street and occasional track use

  • Hawk HPS 5.0 for aggressive street and track use

Feedback from my customers that swapped over to the Porterfield R4-S has been extremely positive. The only “downside” any have said is that it takes a drive or two to get used to the reduced initial bite since they’d gotten so used to the grabby brakes. Once used to it, they’ve all been far happier with the new pads instead of the factory ones.

Cars with CCM brake rotors

The only option I have for these is the Pagid RSC1, which is the most street-friendly of Pagid’s RSC line. I have these customized for Redpants with some tweaks to better meet the expectations of most Aston Martin owners.

For a quick fitment guide for the Hawk, Pagid, and Porterfield brake pads listed above, check out the Brake Pad Options and Fitment Guide in the Brake Pads section of the Info page.

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