In order to clarify the official Porterfield R4-S brake pad bedding procedure, I requested the official instructions from Porterfield. Below is the text from said .pdf as well as a screen shot of the .pdf Porterfield emailed to me:
" Porterfield Bedding procedures recommendations
Street pads (R4-S) are pre-bedded. Just install and drive normally and they will bed themselves in within
about 100 miles. Please avoid the 60+-0 absolute stops upon first installation to see how well they stop.
(Obviously if it is required for safety do so.) This can lead to glazing of the parts. Please allow the 100 or
so miles to pass before being more aggressive with them."
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Here's Porterfield's contact info if you wish to request the instructional .pdf:
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Full Version: Porterfield R4-S brake pad official bedding procedures
That is EXACLY how I bed in every single brake job I do...
Doesn't have to be race pads at all.
I will bed my R4-S pads that I have for my 914 this way.
This way ELIMINATES comebacks on anything.
Rear brakes are much harder to bed than fronts.
Rears usually run 1/3 the heat that the fronts do, and you need to get the brakes hot enough to create the "burning hair" smell.
When the rears are hot enough, the fronts are at excessive temps.
I don't worry about rears as much as I worry about fronts regarding bedding it.
After you've cooked everything up nicely you drive it for 10+ minutes without touching the pedal at all so you need to plan your route accordingly.
If you come to a full stop when hot the pads will "print" to the rotors and you're screwed...
The pads can be saved by lightly touching them to a large flat sanding disc.
The rotors have to, at a minimum, be bead blasted or better to be chucked back up on the lathe and .001 taken off of both sides to create a new bedding surface.
Pain in the ass so DON"T ever stop during the cool down phase.
We have a marvelous twisty county road #4 that runs from Acton to Cleburne (15 miles+) without a single stop sign/light and with a 60-mph limit. It doesn't have much traffic either.
It's my suspension testing and brake bedding road.
You CANNOT have anyone behind you if you're doing this stuff.
"there's a crazy man in a Porsche running down 4 slamming on the brakes and then drag racing back up to excessive speed. It must be drugs or alcohol, Officer."
After the cooling period I'll test the brakes, first softly with hands just lightly gripping wheel. Both application and release are important to not make car swerve on way of another (checking for caliper drag) and then I'll start checking control during application. Brake modulation is critical for me here. Easily controllable application of force and release is what I am hunting for.
Any issues sends it back up on the lift for serious inspection.
Doesn't have to be race pads at all.
I will bed my R4-S pads that I have for my 914 this way.
This way ELIMINATES comebacks on anything.
Rear brakes are much harder to bed than fronts.
Rears usually run 1/3 the heat that the fronts do, and you need to get the brakes hot enough to create the "burning hair" smell.
When the rears are hot enough, the fronts are at excessive temps.
I don't worry about rears as much as I worry about fronts regarding bedding it.
After you've cooked everything up nicely you drive it for 10+ minutes without touching the pedal at all so you need to plan your route accordingly.
If you come to a full stop when hot the pads will "print" to the rotors and you're screwed...
The pads can be saved by lightly touching them to a large flat sanding disc.
The rotors have to, at a minimum, be bead blasted or better to be chucked back up on the lathe and .001 taken off of both sides to create a new bedding surface.
Pain in the ass so DON"T ever stop during the cool down phase.
We have a marvelous twisty county road #4 that runs from Acton to Cleburne (15 miles+) without a single stop sign/light and with a 60-mph limit. It doesn't have much traffic either.
It's my suspension testing and brake bedding road.
You CANNOT have anyone behind you if you're doing this stuff.
"there's a crazy man in a Porsche running down 4 slamming on the brakes and then drag racing back up to excessive speed. It must be drugs or alcohol, Officer."
After the cooling period I'll test the brakes, first softly with hands just lightly gripping wheel. Both application and release are important to not make car swerve on way of another (checking for caliper drag) and then I'll start checking control during application. Brake modulation is critical for me here. Easily controllable application of force and release is what I am hunting for.
Any issues sends it back up on the lift for serious inspection.
Thanks for the clarification. I was told to do around 10 60 to almost 0 stops to bed the RS4 pads.
QUOTE(technicalninja @ Jul 24 2023, 03:49 PM) 
That is EXACLY how I bed in every single brake job I do...
Doesn't have to be race pads at all.
I will bed my R4-S pads that I have for my 914 this way.
This way ELIMINATES comebacks on anything.
Rear brakes are much harder to bed than fronts.
Rears usually run 1/3 the heat that the fronts do, and you need to get the brakes hot enough to create the "burning hair" smell.
When the rears are hot enough, the fronts are at excessive temps.
I don't worry about rears as much as I worry about fronts regarding bedding it.
After you've cooked everything up nicely you drive it for 10+ minutes without touching the pedal at all so you need to plan your route accordingly.
If you come to a full stop when hot the pads will "print" to the rotors and you're screwed...
The pads can be saved by lightly touching them to a large flat sanding disc.
The rotors have to, at a minimum, be bead blasted or better to be chucked back up on the lathe and .001 taken off of both sides to create a new bedding surface.
Pain in the ass so DON"T ever stop during the cool down phase.
We have a marvelous twisty county road #4 that runs from Acton to Cleburne (15 miles+) without a single stop sign/light and with a 60-mph limit. It doesn't have much traffic either.
It's my suspension testing and brake bedding road.
You CANNOT have anyone behind you if you're doing this stuff.
"there's a crazy man in a Porsche running down 4 slamming on the brakes and then drag racing back up to excessive speed. It must be drugs or alcohol, Officer."
After the cooling period I'll test the brakes, first softly with hands just lightly gripping wheel. Both application and release are important to not make car swerve on way of another (checking for caliper drag) and then I'll start checking control during application. Brake modulation is critical for me here. Easily controllable application of force and release is what I am hunting for.
Any issues sends it back up on the lift for serious inspection.
I just want to clarify - for me and everyone who reads this thread . . .
You appear to mention the bedding procedure for Porterfield race pads . . .
This thread is about the official bedding procedure from Porterfield regarding their R4-S pad.
Porterfield says, in essence, their is NO bedding procedure that should ever be applied to their R4-S pads.
Just drive your Porterfield R4-s pads normally for at least 100 miles - do not make any hard stops (unless, obviously, for emergencies), and don't hold the brake pedal on during stops.
To be clear: the bedding procedure for Porterfield R4-S pads is not to perform a bedding procedure.
Hmm. I did not get good braking from my R4-S pads until I went through a couple of very hard core braking sessions, with multiple cycles of 50 to 10 HARD braking followed by getting back up to speed. Things got really hot, and then I drove 30 minutes to cool things down.
Lots of people think a bedding procedure "laps' the pads into the surface of the rotors and just changes the face of the pads.
This is not complete...
It does finish the surface of the pads to the rotors but the most important thing it does is bond a microscopic layer of the pad material to the faces of the rotor.
This is why you heat them up to the point of pad transfer (stinks like burning hair) and then let them cool slowly.
The surface of the rotor is more important to get right than the surface of the pads and this is why you have to get a poorly transferred surface off of the rotor if you screw up the bedding process hence the need for bead blasting or re-turning of the rotor.
It is IMPOSSIBLE to have a set of pre-bedded in pads IMO. Bedding involves the rotors more than the pads.
The normal pads I use for appliance cars is Centric Super Premium thermo-quiet pads.
These are the most expensive common pads available.
The box says they are pre-bedded and pre-scorched.
It's advertising BS.
I bed the crap out of them.
I haven't had a brake comeback since I opened this shop 8 years ago.
This is an unbelievable record. Someone always bitches about noise, dust, or some other complaint.
Every time you change pads you should refresh the surface of the rotors by either replacement or having them turned.
I always have a further micro finishing process done to freshly turned rotors.
While it is still on the brake lathe, I'll hit them with a 3m refinishing pad running 25K on a die grinder. You end up with the finish pattern not being like a vinyl record but being omni-directional (scratches in every direction) This pattern helps bed in considerably.
Exceptions to this rule are having the rotors blanchard ground. That finish is perfect as it comes out. Flywheels are machined in this fashion. If your rotor has either slots or holes the only way it can be refinished is via blanchard grinding. The slots/holes will break the carbide cutting tips on a standard brake lathe.
There is an exception to "new" surface for new pads.
If you put the EXACT same pad compound on a used rotor that is already bedded, you can get away with pad only changes.
So, you've got a race car that uses different pads on different courses.
As long as you stay with the same manufacture, you're usually OK.
There also may be cross brand combinations that will work but if you think you can change pad material at will you're going to have troubles.
A brand-new Dodge truck's owner's manual will state the transmission fluid will last the life of the truck and shouldn't be changed.
The company that makes the transmission (ZF) states both the fluid and filter require changing every 100,00 kilometers (62,000 miles). The fluid is $40 a quart and the filter/pan gasket are priced accordingly.
By the time you're done with a service the cost exceeds $500 which is quite expensive.
The transmission cost more than 7K to replace.
The accountants at Dodge want that truck in the junkyard by 100K miles.
ZF wants the transmission to last 250K+
Who should you believe?
I cannot fathom why a well know brake pad manufacture would state these pads do not require bedding and I'd want to speak with one of their ENGINEERS before I'd take their word. My first question is "what are you doing for the transfer layer on the rotors?"
On your Wife's 10-year-old Camry I'm going to use brand new Blanchard ground hi-carbon electroplated rotors, pre-bedded and pre-scorched pads and I'm going to drive it 15+ miles to bed the crap out of the pads.
You will not have to re-do the brakes I put on that car for 80-100k miles. They will not vibrate or squeak ever and the rotor faces will be textbook perfectly gray without being shiny. They look a little bit like raw titanium.
On my own and my customer's go-fast cars I'm going to be even more critical on getting it exactly right.
Ya'll can do whatever you want...
I'll keep doing what has worked for me for 3 decades +
You should never take anyone's word for granted.
You should make your own decisions.
I do.
Rick
This is not complete...
It does finish the surface of the pads to the rotors but the most important thing it does is bond a microscopic layer of the pad material to the faces of the rotor.
This is why you heat them up to the point of pad transfer (stinks like burning hair) and then let them cool slowly.
The surface of the rotor is more important to get right than the surface of the pads and this is why you have to get a poorly transferred surface off of the rotor if you screw up the bedding process hence the need for bead blasting or re-turning of the rotor.
It is IMPOSSIBLE to have a set of pre-bedded in pads IMO. Bedding involves the rotors more than the pads.
The normal pads I use for appliance cars is Centric Super Premium thermo-quiet pads.
These are the most expensive common pads available.
The box says they are pre-bedded and pre-scorched.
It's advertising BS.
I bed the crap out of them.
I haven't had a brake comeback since I opened this shop 8 years ago.
This is an unbelievable record. Someone always bitches about noise, dust, or some other complaint.
Every time you change pads you should refresh the surface of the rotors by either replacement or having them turned.
I always have a further micro finishing process done to freshly turned rotors.
While it is still on the brake lathe, I'll hit them with a 3m refinishing pad running 25K on a die grinder. You end up with the finish pattern not being like a vinyl record but being omni-directional (scratches in every direction) This pattern helps bed in considerably.
Exceptions to this rule are having the rotors blanchard ground. That finish is perfect as it comes out. Flywheels are machined in this fashion. If your rotor has either slots or holes the only way it can be refinished is via blanchard grinding. The slots/holes will break the carbide cutting tips on a standard brake lathe.
There is an exception to "new" surface for new pads.
If you put the EXACT same pad compound on a used rotor that is already bedded, you can get away with pad only changes.
So, you've got a race car that uses different pads on different courses.
As long as you stay with the same manufacture, you're usually OK.
There also may be cross brand combinations that will work but if you think you can change pad material at will you're going to have troubles.
A brand-new Dodge truck's owner's manual will state the transmission fluid will last the life of the truck and shouldn't be changed.
The company that makes the transmission (ZF) states both the fluid and filter require changing every 100,00 kilometers (62,000 miles). The fluid is $40 a quart and the filter/pan gasket are priced accordingly.
By the time you're done with a service the cost exceeds $500 which is quite expensive.
The transmission cost more than 7K to replace.
The accountants at Dodge want that truck in the junkyard by 100K miles.
ZF wants the transmission to last 250K+
Who should you believe?
I cannot fathom why a well know brake pad manufacture would state these pads do not require bedding and I'd want to speak with one of their ENGINEERS before I'd take their word. My first question is "what are you doing for the transfer layer on the rotors?"
On your Wife's 10-year-old Camry I'm going to use brand new Blanchard ground hi-carbon electroplated rotors, pre-bedded and pre-scorched pads and I'm going to drive it 15+ miles to bed the crap out of the pads.
You will not have to re-do the brakes I put on that car for 80-100k miles. They will not vibrate or squeak ever and the rotor faces will be textbook perfectly gray without being shiny. They look a little bit like raw titanium.
On my own and my customer's go-fast cars I'm going to be even more critical on getting it exactly right.
Ya'll can do whatever you want...
I'll keep doing what has worked for me for 3 decades +
You should never take anyone's word for granted.
You should make your own decisions.
I do.
Rick
“Bedding involves the rotors more than the pads.”
Exactly!
The Porterfield bulletin might work if you are just replacing pads but makes no mention of new or used rotors - and that makes a huge difference.
If we sent out our customers cars with brand new pads and rotors and didn’t bed in the brakes, half of them would end up in accidents at the first stop sign. The other half would turn the car around and tell us the brakes don’t work. New pads and rotors typically feel like they don’t work until they are bedded in together. Once they are ready, they will actually do a good job stopping the car.
Exactly!
The Porterfield bulletin might work if you are just replacing pads but makes no mention of new or used rotors - and that makes a huge difference.
If we sent out our customers cars with brand new pads and rotors and didn’t bed in the brakes, half of them would end up in accidents at the first stop sign. The other half would turn the car around and tell us the brakes don’t work. New pads and rotors typically feel like they don’t work until they are bedded in together. Once they are ready, they will actually do a good job stopping the car.
Good info. These posts coupled with what Eric advises (a "proper' bedding procedure) make it pretty clear. Which is good timing for me because I have a set of R4-S waiting to go on.
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