My brake squeal.......
Discussion
Just a quick one for the more technical among us but my car goes in again tomorrow for more work which includes the on going brake
squeal.
Today young Rango and I have cleaned the car after its recent road trip and checked and photographed other areas that are to be worked on.
Whilst grumbling about the brake noise it was noted that the same disc is fitted to each wheel with the near side of the car having the grooves
highest point facing up or backwards........like this \
Strangely to me the drivers side are fitted with the same disc and the groove faces the other way and has the groove facing forward......like this /.
So clearly the same part is used for each wheel and we got to wondering if this may contribute to the squeal which appears to come from the
drivers side of the car.
Sorry if this is a no brainer to many but my question is born out of frustration as well as an attempt to help the dealership as this is now the 4th
or 5th attempt to fix it,its had all the blue stuff and plenty of high speed braking to try and clear it but it just persists.
The technician thinks different pads may be needed which seems strange as I'm sure they all leave the factory with the correct issue fitted and
remembering this is a new car.
Looking at the internet and at Brembo for instance it shows their discs with the grooves clearly running in the same direction on all 4 corners
with the highest point of the groove leaning backwards like this \ .Its probably just a design thing and might vary from one manufacturer to
another but it just seems odd to me,baring in mind I'm not a mechanic.
Should the grooves or rotors not spin the build up or dust,water and gases away from the centre of the wheel and not in opposite by drawing
them in to the wheel centre.
Thanks, I await the enlightenment.
squeal.
Today young Rango and I have cleaned the car after its recent road trip and checked and photographed other areas that are to be worked on.
Whilst grumbling about the brake noise it was noted that the same disc is fitted to each wheel with the near side of the car having the grooves
highest point facing up or backwards........like this \
Strangely to me the drivers side are fitted with the same disc and the groove faces the other way and has the groove facing forward......like this /.
So clearly the same part is used for each wheel and we got to wondering if this may contribute to the squeal which appears to come from the
drivers side of the car.
Sorry if this is a no brainer to many but my question is born out of frustration as well as an attempt to help the dealership as this is now the 4th
or 5th attempt to fix it,its had all the blue stuff and plenty of high speed braking to try and clear it but it just persists.
The technician thinks different pads may be needed which seems strange as I'm sure they all leave the factory with the correct issue fitted and
remembering this is a new car.
Looking at the internet and at Brembo for instance it shows their discs with the grooves clearly running in the same direction on all 4 corners
with the highest point of the groove leaning backwards like this \ .Its probably just a design thing and might vary from one manufacturer to
another but it just seems odd to me,baring in mind I'm not a mechanic.
Should the grooves or rotors not spin the build up or dust,water and gases away from the centre of the wheel and not in opposite by drawing
them in to the wheel centre.
Thanks, I await the enlightenment.
Ed50 said:
Just a quick one for the more technical among us but my car goes in again tomorrow for more work which includes the on going brake
squeal.
Today young Rango and I have cleaned the car after its recent road trip and checked and photographed other areas that are to be worked on.
Whilst grumbling about the brake noise it was noted that the same disc is fitted to each wheel with the near side of the car having the grooves
highest point facing up or backwards........like this \
Strangely to me the drivers side are fitted with the same disc and the groove faces the other way and has the groove facing forward......like this /.
So clearly the same part is used for each wheel and we got to wondering if this may contribute to the squeal which appears to come from the
drivers side of the car.
Sorry if this is a no brainer to many but my question is born out of frustration as well as an attempt to help the dealership as this is now the 4th
or 5th attempt to fix it,its had all the blue stuff and plenty of high speed braking to try and clear it but it just persists.
The technician thinks different pads may be needed which seems strange as I'm sure they all leave the factory with the correct issue fitted and
remembering this is a new car.
Looking at the internet and at Brembo for instance it shows their discs with the grooves clearly running in the same direction on all 4 corners
with the highest point of the groove leaning backwards like this \ .Its probably just a design thing and might vary from one manufacturer to
another but it just seems odd to me,baring in mind I'm not a mechanic.
Should the grooves or rotors not spin the build up or dust,water and gases away from the centre of the wheel and not in opposite by drawing
them in to the wheel centre.
Thanks, I await the enlightenment.
Looking at mine as fitted by BR, if you took all four wheels off the car and laid them on the ground, rim side up, all of the grooves would point in the same direction.squeal.
Today young Rango and I have cleaned the car after its recent road trip and checked and photographed other areas that are to be worked on.
Whilst grumbling about the brake noise it was noted that the same disc is fitted to each wheel with the near side of the car having the grooves
highest point facing up or backwards........like this \
Strangely to me the drivers side are fitted with the same disc and the groove faces the other way and has the groove facing forward......like this /.
So clearly the same part is used for each wheel and we got to wondering if this may contribute to the squeal which appears to come from the
drivers side of the car.
Sorry if this is a no brainer to many but my question is born out of frustration as well as an attempt to help the dealership as this is now the 4th
or 5th attempt to fix it,its had all the blue stuff and plenty of high speed braking to try and clear it but it just persists.
The technician thinks different pads may be needed which seems strange as I'm sure they all leave the factory with the correct issue fitted and
remembering this is a new car.
Looking at the internet and at Brembo for instance it shows their discs with the grooves clearly running in the same direction on all 4 corners
with the highest point of the groove leaning backwards like this \ .Its probably just a design thing and might vary from one manufacturer to
another but it just seems odd to me,baring in mind I'm not a mechanic.
Should the grooves or rotors not spin the build up or dust,water and gases away from the centre of the wheel and not in opposite by drawing
them in to the wheel centre.
Thanks, I await the enlightenment.
When replaced on the car, the driver side point backwards and the passenger side point forward. I get the odd squeak which is normally cured by a hard brake from speed. Obviously on my drive which is over a mile long.
I hope that is of use.
So in my theory: One side must be incorrect, now in all the cars I've been involved with, i've always been taught the grooves should always point towards the rear of the car.
This is to draw away the gasses from the brake pad. This build up of gases is one of the key causes of braking fade when under heavy use, hence why performance brakes are drilled and grooved/slotted to remove: heat & gas, also it helps to keep the weight of the disc to a minimum.
F1, British touring cars, Le Mans and all other forms of motor sport where performance brakes are used, they all seem to have followed what i've been taught the grooves should point towards the rear of the car.
Now sometimes on vented discs, the veins inside the vents are directional like this:
This further helps to pull air through the vents to cool the discs, now i am not sure if the aston discs have directional veins or not, internet searching cant seem to answer whether they do or don't, but if the do in theory one side of the car is working in reverse.....
Any answer as to whether the aston o.e discs have directional veins would answer my theory.
This is to draw away the gasses from the brake pad. This build up of gases is one of the key causes of braking fade when under heavy use, hence why performance brakes are drilled and grooved/slotted to remove: heat & gas, also it helps to keep the weight of the disc to a minimum.
F1, British touring cars, Le Mans and all other forms of motor sport where performance brakes are used, they all seem to have followed what i've been taught the grooves should point towards the rear of the car.
Now sometimes on vented discs, the veins inside the vents are directional like this:
This further helps to pull air through the vents to cool the discs, now i am not sure if the aston discs have directional veins or not, internet searching cant seem to answer whether they do or don't, but if the do in theory one side of the car is working in reverse.....
Any answer as to whether the aston o.e discs have directional veins would answer my theory.
Edited by rango am on Sunday 22 September 19:50
That's my boy Rangi stick your neck out and await the executioners blade...............that said well researched and interestingly helpful, I can see you
behind a desk at Gaydon if you keep this up........
Well there's bound to be some technical wizard out there that can put us out of our braking misery.....................please.
I wouldn't put it past them on current form to have fitted the incorrect discs to one side....
behind a desk at Gaydon if you keep this up........
Well there's bound to be some technical wizard out there that can put us out of our braking misery.....................please.
I wouldn't put it past them on current form to have fitted the incorrect discs to one side....
Ed50 said:
That's my boy Rangi stick your neck out and await the executioners blade...............that said well researched and interestingly helpful, I can see you
behind a desk at Gaydon if you keep this up........
Well there's bound to be some technical wizard out there that can put us out of our braking misery.....................please.
I wouldn't put it past them on current form to have fitted the incorrect discs to one side....
Ed, Rango's logic is perfect but BR do know what they are doing so maybe they will respond.behind a desk at Gaydon if you keep this up........
Well there's bound to be some technical wizard out there that can put us out of our braking misery.....................please.
I wouldn't put it past them on current form to have fitted the incorrect discs to one side....
woolders said:
Ed, Rango's logic is perfect but BR do know what they are doing so maybe they will respond.
I hope Mike does offer some wisdom cus after what I believe to be 5 attempts at the Dealership now things are gettingtedious but it must be as frustrating to the Dealership Guys as it is to me.
I now a lot of people struggle with this issue but over my previous cars it has been sorted relatively quickly,this one just seems to
get worse.
Had a close inspection today with Rango and you can clearly see the blue paste smeared everywhere but all to no avail,hence us noticing
the disc grooves facing opposite directions.
Ok, info as requested............
The diagram above shows the VANES and not the GROOVES as the original poster mentioned.
The VANES, ie the area between the inner and outer faces when using vented discs, as we all do on Astons, should always point BACKWARDS at the top of the disc when viewed from the outside as in Rango's diagram. This draws the air out from the centre of the disc aiding the removal of heat as the outside acts like a venturi, drawing the air out radially. Fitted the other way around would use the air pressure to force the air down into the vent, heating the hub area of the disc.
However, the OP mentioned the grooves, and these are on the outer face of the disc on the steel brakes. These grooves continually clean the pad face during use and also vent gases between the pad and disc surface and aid water film dispersal. These should always point FORWARDS. However, this would lead the discs being manufactured as sided, doubling the parts inventory and increasing production costs.
SO,
ED50 must have his description slightly muddles because he describes the two discs as a mirror image, ie as they should be, and not the same parts as he suggests.
Yes, one side of your car does have the correct original discs running in the wrong direction, but as Aston do not actually make any made for the correct orientation, you are stuck as they are.
This would NOT cause the noise, which if squealing, is high speed oscillation of the disc. This can be rectified by deglazing the disc and/or removal, cleaning and lubrication of the pads during installation and using a anti-squeal paste on the back face of the pad. It can also be caused by glazing of the pad face, but this would be very unusual as this is the function of the slots, to remove this and essentially reface the pads during brake application.
8Tech.
As a footnote, drilled discs are a better option on road cars and slotted discs are the best option for motorsport. Hence my solution.
[pic]
[/pic]
[pic]
[/pic]
I would also mention that the Aston discs do not have continuous vents in their discs but are actually staggered oval posts that are not actually directional.
The diagram above shows the VANES and not the GROOVES as the original poster mentioned.
The VANES, ie the area between the inner and outer faces when using vented discs, as we all do on Astons, should always point BACKWARDS at the top of the disc when viewed from the outside as in Rango's diagram. This draws the air out from the centre of the disc aiding the removal of heat as the outside acts like a venturi, drawing the air out radially. Fitted the other way around would use the air pressure to force the air down into the vent, heating the hub area of the disc.
However, the OP mentioned the grooves, and these are on the outer face of the disc on the steel brakes. These grooves continually clean the pad face during use and also vent gases between the pad and disc surface and aid water film dispersal. These should always point FORWARDS. However, this would lead the discs being manufactured as sided, doubling the parts inventory and increasing production costs.
SO,
ED50 must have his description slightly muddles because he describes the two discs as a mirror image, ie as they should be, and not the same parts as he suggests.
Yes, one side of your car does have the correct original discs running in the wrong direction, but as Aston do not actually make any made for the correct orientation, you are stuck as they are.
This would NOT cause the noise, which if squealing, is high speed oscillation of the disc. This can be rectified by deglazing the disc and/or removal, cleaning and lubrication of the pads during installation and using a anti-squeal paste on the back face of the pad. It can also be caused by glazing of the pad face, but this would be very unusual as this is the function of the slots, to remove this and essentially reface the pads during brake application.
8Tech.
As a footnote, drilled discs are a better option on road cars and slotted discs are the best option for motorsport. Hence my solution.
[pic]
[/pic][pic]
[/pic]I would also mention that the Aston discs do not have continuous vents in their discs but are actually staggered oval posts that are not actually directional.
Edited by 8Tech on Sunday 22 September 21:53
rango am said:
Now sometimes on vented discs, the veins inside the vents are directional like this:
This further helps to pull air through the vents to cool the discs, now i am not sure if the aston discs have directional veins or not, internet searching cant seem to answer whether they do or don't, but if the do in theory one side of the car is working in reverse.....
I had a set of Willwood discs on a previous car, and they were indeed handed, so that the veins ran in the same directionThis further helps to pull air through the vents to cool the discs, now i am not sure if the aston discs have directional veins or not, internet searching cant seem to answer whether they do or don't, but if the do in theory one side of the car is working in reverse.....
"However, the OP mentioned the grooves, and these are on the outer face of the disc on the steel brakes. These grooves continually clean the pad face during use and also vent gases between the pad and disc surface and aid water film dispersal. These should always point FORWARDS. However, this would lead the discs being manufactured as sided, doubling the parts inventory and increasing production costs."
You state the grooves in the disc face should face forwards ^^^^ Yet your picture of your discs they face backwards?
You state the grooves in the disc face should face forwards ^^^^ Yet your picture of your discs they face backwards?
"However, this would lead the discs being manufactured as sided, doubling the parts inventory and increasing production costs."
Every other manufacturer i've researched does make there discs as sided parts.
Most either mark with a rotation arrow ---> like such.
Same as rotational tyres having an arrow on the side wall.
Every other manufacturer i've researched does make there discs as sided parts.
Most either mark with a rotation arrow ---> like such.
Same as rotational tyres having an arrow on the side wall.
rango am said:
"However, the OP mentioned the grooves, and these are on the outer face of the disc on the steel brakes. These grooves continually clean the pad face during use and also vent gases between the pad and disc surface and aid water film dispersal. These should always point FORWARDS. However, this would lead the discs being manufactured as sided, doubling the parts inventory and increasing production costs."
You state the grooves in the disc face should face forwards ^^^^ Yet your picture of your discs they face backwards?
Correct, they are original Aston Martin discs with the wrong orientation on the grooves, then drilled.You state the grooves in the disc face should face forwards ^^^^ Yet your picture of your discs they face backwards?
rango am said:
However, the OP mentioned the grooves, and these are on the outer face of the disc on the steel brakes.
Now, I'm going to stick my neck out.Ed50's avatar picture is of a V12V - so the brakes are CCM..google images show they don't have grooves.
Scrub this - saw post about MPG having driven in 'D' - so it's not a V12V
Edited by dredders on Monday 23 September 16:55
Edited by dredders on Monday 23 September 16:58
8Tech said:
Correct, they are original Aston Martin discs with the wrong orientation on the grooves, then drilled.
OK then but is this an industry wide thing or just an Aston or even a Bean Counter thing........? one part fits all.Secondly is this sound practice in view of other comments or indeed lead to my and many others brake squeal
issues.
Please say that really each side should face the same way ,ie having a L/H and R/H set as this would be a technical first for me........
Ed50 said:
OK then but is this an industry wide thing or just an Aston or even a Bean Counter thing........? one part fits all.
Secondly is this sound practice in view of other comments or indeed lead to my and many others brake squeal
issues.
Please say that really each side should face the same way ,ie having a L/H and R/H set as this would be a technical first for me........
Well in theory Ed yes both sides should face the same way, its just which way to face them?Secondly is this sound practice in view of other comments or indeed lead to my and many others brake squeal
issues.
Please say that really each side should face the same way ,ie having a L/H and R/H set as this would be a technical first for me........
I managed to find this short video which kind of explains it a little bit.
http://www.youtube.com/watch?v=5OWM1wttWA8
But in this video he states Brembo say the slots should lean towards the front of the car, but everyone else faces them pointing towards the rear.
So are Brembo the ones doing it backwards and everyone else is right or are Brembo the ones who have got it right?
But in this theory i'm sure you said Brembo make the brakes for the v8vs which means they should face towards the front of the car on both sides?
However the rotors them selves are mounted on hub which then in turn bolt to the hub of the car, so in this theory aston could unbolt the rotor (disc face) from the black centre spin it round and mount it so both sides of the vehicle match with the slots all pointing the same way?
So in this picture of the v8vs brake calliper and rotor the disc face is detachable from the black centre:
Purdey suffered from the same high frequency squeal that is driving you mad. My dealer fitted blue pads which sat behind the actual brake pads , problem sorted! After 5600 miles Pearl's brakes are now starting to do the same that is despite ferocious braking over the last week. How about this as a reason for not sorting the problem. The factory are passing the ownership of the problem back to the dealer for financial reasons!
Pearl is having a once over at BR tomorrow , I shall mention it knowing full well that it will be sorted. !!!
Pearl is having a once over at BR tomorrow , I shall mention it knowing full well that it will be sorted. !!!
[quote=robgt] The factory are passing the ownership of the problem back to the dealer for financial reasons!
Classic absolute classic Rob.
My answer to that will be along the lines of the following.
I will be passing the ownership of the problem back to the Dealer for pissed off reasons..........
.
The whole AM quality thing is turning into a Circus at the moment, a Circus where someone needs to start cracking a whip.
Classic absolute classic Rob.
My answer to that will be along the lines of the following.
I will be passing the ownership of the problem back to the Dealer for pissed off reasons..........
.The whole AM quality thing is turning into a Circus at the moment, a Circus where someone needs to start cracking a whip.
Gassing Station | Aston Martin | Top of Page | What's New | My Stuff