Mick,


Re: brakes, "not racing" doesn't mean you don't have to stop that quickly. Stuff happens-- deer, idiots on the highway, etc. The difference is heat: on a race track you are doing a lot of hard braking, and you need a hard compound that won't soften. But a hard compound is no good when it is cold. We've run the gamut and went back to factory pads (made by Textar I think), they work very well over a wide range.

Measure your rotors, 30/22mm (front/rear) is the minimum (for S4+). And respect the factory 2mm min pad thickness, that's more about insulating the pistons, seals and fluid from the heat. We always leave the calipers in place for pad replacement, just push the pistons back with the pads and then pull the pads. Opening the bleeder is a good idea, and partially bleeds the system when you add fresh fluid to the reservoir. But a full flush is also a good idea.

Porsche uses "damping plates" which stick to the back of the pads to reduce brake squeal. Not expensive, the problem is that they have fingers which extend into the allow pistons and don't allow the pads to just be slipped out. We don't bother. Adding a bit of high-temp anti-seize compound to the steel pad backing plate does help-- on the edge where the backing plate meets the caliper, and on the back where it meets the piston. And sometimes they squeak.

Pad warning-sensors are a one-time deal, the rotor edge saws through a wire loop embedded in plastic. So if the warning goes off, the offending sensor needs replacing. And if the rotor has a lip, then the warning goes off early. Our sensors were bypassed by a PO long ago and not missed, it is easy enough to check the pads.

Cheers, Jim

----- Original Message -----
Date: Sat, 2 Sep 2023 15:41:45 +0000 (UTC)
From: "mick cowles via " <mickcowles=[email protected]>
To: [email protected]
Subject: [PacNW928] Portland area meetup?, Brake pad questions

?Michael B- It would be great to meet up sometime! I was thinking some Portland area meetups would make sense. Ken and I were talking about tinkering with the vacuum line on my automatic transmission. (Shifts hard when coasting in stop and go traffic). Also, I just shot Tom928 an email seeing if he might be interested in getting together for some projects. It would be cool if other Pacnw928 guys could join us, but it may not be practical due to the distance involved. I'm always happy to help people with 928 projects...heck, I don't even care if its a 928. I just enjoy wrenching and learning about mechanical stuff. Probably, the most urgent task on my shark is to swap out the rear brake pads. I've done brakes on Corollas, but never on a 928. Seems pretty straight forward. I'm down to 1-2 mm on those rear pads. When Ken took a peek at the rotors, he thought they might be good for one more set of pads. So I'd hate to score up these rotors by putting the job off too long. (Who knows if the brake pad sensors will work, right??)

Pacnw928 guys- I could use some advice on choosing the right brake pads. I've driven a lot of beaters in my life, and the stopping distance of those cars was terrible, so anything I put in the 928 will be better than what I'm used to. I'm not racing, so I don't need to stop that quickly. Also, I don't care that much about dusting. I can't see thru to my calipers and rotors, so dust doesn't bother me. My priorities are a pad that won't eat my rotors quickly, and one that doesn't squeak. Any suggestions? Also, some advice about the best suppliers for 928 brake pads would be appreciated.

Thanks!
Mick

? ? ?On Friday, September 1, 2023 at 04:29:51 PM PDT, Michael Benno <michael.benno@...> wrote:
?Hey,?all?it was great to meet up with you all. Meet some new faces and reconnect with some old ones. Keith, you are a very generous host.?
Peter, I am so impressed with your 928 journeys!?
Mick, I am in Portland and would be happy to meet up whenever. Let me know it you need anything.??


On Fri, Sep 1, 2023 at 9:19?AM mick cowles via <mickcowles=[email protected]> wrote:

?Peter- Glad you got the hood issue sorted out and got a chance to look at the timing belt. It was a pleasure meeting you and talking about 928's and wines! Let me know if that Malbec I gave you is any good.

Andy- Thanks for taking the group photo. My sister and friends enjoyed seeing that. They've been following my journey with the 928 repairs since inheriting it, and were glad to see I got some help and have met some friends!

Pacnw928guys- I mentioned getting together in the fall. I'll start rattling everyone's cages again in a couple months! If anyone is near Portland and needs help with anything before then, feel free email me or text at the number below.

Best Regards,
Mick Cowles
(503) 484-4226

? ? ?On Monday, August 28, 2023 at 09:26:33 AM PDT, Peter S s/v Dawa II <scottpeterd@...> wrote:
It was great to finally put some faces to online names.? I had a great time.

The run back gave me a chance to sort out the mixture on the CIS.? I came back up via 101/3 through Shelton.? Sunday was an antique car show, so I stayed a while.

Ken: ?stopped at Napa and got some lithium grease.? The bonnet now works!

And thanks everyone for the help on adjusting the timing belt.

Sadly, this was pretty much the last trip for the 928.? This weekend I leave for 2 months for sailing. ?


Cheers






--
1992 Porsche?928 GTS Japan market







----- End of Original Message -----

Hi Jeff,

Thanks for all of that! Very helpful! Especially about cleaning the piston boot seals, and bleeding before removing the pads. You also make a great point about the abrasiveness of brake pads and the cost of new rotors. And that's really at the crux of the question I'm posing....Which brand of brake pads will be easiest on my rotors? If there's another brand of pad you'd recommend that is less abrasive than the Textar pads and isn't prone to squealing, I'd appreciate it. If you have suggestions about which suppliers to use, that would be great too!

Thanks!
Mick

On Saturday, September 2, 2023 at 10:47:26 AM PDT, Jeff Mohler <speedtoys.racing@...> wrote:

"you need a hard compound that won't soften"

That's not a thing.? You need a compound that can do high heat stops more than once or twice.? ?It's about their coefficient of friction AT high temperatures.? They can SEEM harder, but that's not the primary, secondary..and so on, requirement.? It's a probable result.

And any brake pad, can lock up the tires a few times...but then again, coefficients/etc.

I like the Textar, but they were entirely not worth the cost of rotors that they bring with them.? They are mildly abrasive at all temperatures...and iron laden dust is not a friend.? On my 330mm kit, it's a huge issue (rotor cost) that makes OE rotors seem casually affordable.? I know you felt the PF pads were a tad lacking "cold" but I dont?notice on street work, spirited driving always has warm up cycles..not just dive in cold.? And..I'll probly never buy a set of rotors again...and at $475 per rotor ring..

When replacing pads..an old toothbrush to clean out the dust/debris from the piston boot seals is a friendly thing to do as well.

ALso, the easy way to check the pads is to check brake fluid level.? :). NEVER add fluid when it's "low"..that's pad wear...and now you have a real problem pushing the pistons back in..

Brake fluid, even if never abused, gets squishy over time, bleed BEFORE removing old pads, then you don't?have to bleed down the fluid that pushing the pistons back in..would force back UP the system.

And yes, I beat the F out of my brakes a # of times a year...getting air at Thunderhill is a challenge for example.? ?:)

On Sat, Sep 2, 2023 at 10:29?AM Jim Corenman <jcorenman@...> wrote:

Mick,


Re: brakes, "not racing" doesn't mean you don't have to stop that quickly. Stuff happens-- deer, idiots on the highway, etc. The difference is heat: on a race track you are doing a lot of hard braking, and you need a hard compound that won't soften. But a hard compound is no good when it is cold. We've run the gamut and went back to factory pads (made by Textar I think), they work very well over a wide range.

Measure your rotors, 30/22mm (front/rear) is the minimum (for S4+). And respect the factory 2mm min pad thickness, that's more about insulating the pistons, seals and fluid from the heat. We always leave the calipers in place for pad replacement, just push the pistons back with the pads and then pull the pads. Opening the bleeder is a good idea, and partially bleeds the system when you add fresh fluid to the reservoir. But a full flush is also a good idea.

Porsche uses "damping plates" which stick to the back of the pads to reduce brake squeal. Not expensive, the problem is that they have fingers which extend into the allow pistons and don't allow the pads to just be slipped out. We don't bother. Adding a bit of high-temp anti-seize compound to the steel pad backing plate does help-- on the edge where the backing plate meets the caliper, and on the back where it meets the piston. And sometimes they squeak.

Pad warning-sensors are a one-time deal, the rotor edge saws through a wire loop embedded in plastic. So if the warning goes off, the offending sensor needs replacing. And if the rotor has a lip, then the warning goes off early. Our sensors were bypassed by a PO long ago and not missed, it is easy enough to check the pads.

Cheers, Jim

----- Original Message -----
Date: Sat, 2 Sep 2023 15:41:45 +0000 (UTC)
From: "mick cowles via " <mickcowles=[email protected]>
To: [email protected]
Subject: [PacNW928] Portland area meetup?, Brake pad questions

?Michael B- It would be great to meet up sometime! I was thinking some Portland area meetups would make sense. Ken and I were talking about tinkering with the vacuum line on my automatic transmission. (Shifts hard when coasting in stop and go traffic). Also, I just shot Tom928 an email seeing if he might be interested in getting together for some projects. It would be cool if other Pacnw928 guys could join us, but it may not be practical due to the distance involved. I'm always happy to help people with 928 projects...heck, I don't even care if its a 928. I just enjoy wrenching and learning about mechanical stuff. Probably, the most urgent task on my shark is to swap out the rear brake pads. I've done brakes on Corollas, but never on a 928. Seems pretty straight forward. I'm down to 1-2 mm on those rear pads. When Ken took a peek at the rotors, he thought they might be good for one more set of pads. So I'd hate to score up these rotors by putting the job off too long. (Who knows if the brake pad sensors will work, right??)

Pacnw928 guys- I could use some advice on choosing the right brake pads. I've driven a lot of beaters in my life, and the stopping distance of those cars was terrible, so anything I put in the 928 will be better than what I'm used to. I'm not racing, so I don't need to stop that quickly. Also, I don't care that much about dusting. I can't see thru to my calipers and rotors, so dust doesn't bother me. My priorities are a pad that won't eat my rotors quickly, and one that doesn't squeak. Any suggestions? Also, some advice about the best suppliers for 928 brake pads would be appreciated.

Thanks!
Mick

? ? ?On Friday, September 1, 2023 at 04:29:51 PM PDT, Michael Benno <michael.benno@...> wrote:
?Hey,?all?it was great to meet up with you all. Meet some new faces and reconnect with some old ones. Keith, you are a very generous host.?
Peter, I am so impressed with your 928 journeys!?
Mick, I am in Portland and would be happy to meet up whenever. Let me know it you need anything.??


On Fri, Sep 1, 2023 at 9:19?AM mick cowles via <mickcowles=[email protected]> wrote:

?Peter- Glad you got the hood issue sorted out and got a chance to look at the timing belt. It was a pleasure meeting you and talking about 928's and wines! Let me know if that Malbec I gave you is any good.

Andy- Thanks for taking the group photo. My sister and friends enjoyed seeing that. They've been following my journey with the 928 repairs since inheriting it, and were glad to see I got some help and have met some friends!

Pacnw928guys- I mentioned getting together in the fall. I'll start rattling everyone's cages again in a couple months! If anyone is near Portland and needs help with anything before then, feel free email me or text at the number below.

Best Regards,
Mick Cowles
(503) 484-4226

? ? ?On Monday, August 28, 2023 at 09:26:33 AM PDT, Peter S s/v Dawa II <scottpeterd@...> wrote:
It was great to finally put some faces to online names.? I had a great time.

The run back gave me a chance to sort out the mixture on the CIS.? I came back up via 101/3 through Shelton.? Sunday was an antique car show, so I stayed a while.

Ken: ?stopped at Napa and got some lithium grease.? The bonnet now works!

And thanks everyone for the help on adjusting the timing belt.

Sadly, this was pretty much the last trip for the 928.? This weekend I leave for 2 months for sailing. ?


Cheers






--
1992 Porsche?928 GTS Japan market







----- End of Original Message -----

--

---
Gustatus Similis Pullus

Jeff,

Thanks for your input, and good point on rotor wear: rotors aren't cheap. But the factory pads don't seem all that bad. We fit GTS brakes with new RB rotors and factory pads after the 5.9L was built. The rotors currently measure 31.6mm (32.2 new) after 55K miles - about 25% worn. I can deal with that.

I guess we're one of the 5%. And 95% of the time we were very happy with the Porterfield pads, but for a street car my expectation is that the brakes work immediately and consistently at any temperature. (By "work", I mean able to lock up i.e. trigger ABS as needed). They were great when warmed up, no mountain too tall or downhill curve too steep. But we had too many close calls when they weren't. Just simple stuff like heading to town on a cold morning when Bambi-with-a-death-wish jumps out of the bushes.

Sooo: What else is out there, pad-wise, with a sufficiently high coefficient of friction to lock the brakes on a cold (40F) morning with no warmup, yet also able to do serious mountain driving in summer temps? And of course easy on rotors, minimal dust, quiet, etc?

And perhaps more relevant for Mick: For the past many years (decades) we have run PBR pads (sold by 928 Int'l) on our stock '88 S4 with great results. That car doesn't get to any of the fun mountain stuff but otherwise those pads can trigger ABS immediately and consistently at any temperature.

I've also got a set of partly-used Porterfield pads (GTS and S4 fronts plus one set of rears) for anyone who wants to give them a try, just cover shipping.

Cheers, Jim

----- Original Message -----
From: "Jeff Mohler" <speedtoys.racing@...>
Date: Sat, 2 Sep 2023 11:41:53 -0700
Subject: Re: [PacNW928] Portland area meetup?, Brake pad questions
To: [email protected]

Just me...but 95% of people just driving the car...will love the
Porterfield pads..the dust wont hurt wheels either.



When i sold pads retail online..this was the go-to for most people.
They're not bad cold, but get progressively more responsive as they warm
up.? I wouldnt say they are GREAT pads for a really set of spirited track
laps however...the 928 brakes were big for the day and tires of the day,
but not TOday.? ;)

My wife and I have had many cars..and they were all 1-rotor-set cars on
these pads...up to 170 miles which is the longest we drove any single car,
that was a Mazdaspeed3.

On Sat, Sep 2, 2023 at 11:17?AM mick cowles via <mickcowles=
[email protected]> wrote:

> Hi Jeff,
>
> Thanks for all of that! Very helpful! Especially about cleaning the piston
> boot seals, and bleeding before removing the pads. You also make a great
> point about the abrasiveness of brake pads and the cost of new rotors. And
> that's really at the crux of the question I'm posing....Which brand of
> brake pads will be easiest on my rotors? If there's another brand of pad
> you'd recommend that is less abrasive than the Textar pads and isn't prone
> to squealing, I'd appreciate it. If you have suggestions about which
> suppliers to use, that would be great too!
>
> Thanks!
> Mick
> On Saturday, September 2, 2023 at 10:47:26 AM PDT, Jeff Mohler <
> speedtoys.racing@...> wrote:
>
>
> "you need a hard compound that won't soften"
>
> That's not a thing.? You need a compound that can do high heat stops more
> than once or twice.? ?It's about their coefficient of friction AT high
> temperatures.? They can SEEM harder, but that's not the primary,
> secondary..and so on, requirement.? It's a probable result.
>
> And any brake pad, can lock up the tires a few times...but then again,
> coefficients/etc.
>
> I like the Textar, but they were entirely not worth the cost of rotors
> that they bring with them.? They are mildly abrasive at all
> temperatures...and iron laden dust is not a friend.? On my 330mm kit, it's
> a huge issue (rotor cost) that makes OE rotors seem casually affordable.? I
> know you felt the PF pads were a tad lacking "cold" but I dont notice on
> street work, spirited driving always has warm up cycles..not just dive in
> cold.? And..I'll probly never buy a set of rotors again...and at $475 per
> rotor ring..
>
> When replacing pads..an old toothbrush to clean out the dust/debris from
> the piston boot seals is a friendly thing to do as well.
>
> ALso, the easy way to check the pads is to check brake fluid level.? :).
> NEVER add fluid when it's "low"..that's pad wear...and now you have a real
> problem pushing the pistons back in..
>
> Brake fluid, even if never abused, gets squishy over time, bleed BEFORE
> removing old pads, then you don't have to bleed down the fluid that pushing
> the pistons back in..would force back UP the system.
>
> And yes, I beat the F out of my brakes a # of times a year...getting air
> at Thunderhill is a challenge for example.? ?:)
>
>
>
>
> On Sat, Sep 2, 2023 at 10:29?AM Jim Corenman <jcorenman@...>
> wrote:
>
> Mick,
>
>
> Re: brakes, "not racing" doesn't mean you don't have to stop that quickly.
> Stuff happens-- deer, idiots on the highway, etc. The difference is heat:
> on a race track you are doing a lot of hard braking, and you need a hard
> compound that won't soften. But a hard compound is no good when it is cold.
> We've run the gamut and went back to factory pads (made by Textar I think),
> they work very well over a wide range.
>
> Measure your rotors, 30/22mm (front/rear) is the minimum (for S4+). And
> respect the factory 2mm min pad thickness, that's more about insulating the
> pistons, seals and fluid from the heat. We always leave the calipers in
> place for pad replacement, just push the pistons back with the pads and
> then pull the pads. Opening the bleeder is a good idea, and partially
> bleeds the system when you add fresh fluid to the reservoir. But a full
> flush is also a good idea.
>
> Porsche uses "damping plates" which stick to the back of the pads to
> reduce brake squeal. Not expensive, the problem is that they have fingers
> which extend into the allow pistons and don't allow the pads to just be
> slipped out. We don't bother. Adding a bit of high-temp anti-seize compound
> to the steel pad backing plate does help-- on the edge where the backing
> plate meets the caliper, and on the back where it meets the piston. And
> sometimes they squeak.
>
> Pad warning-sensors are a one-time deal, the rotor edge saws through a
> wire loop embedded in plastic. So if the warning goes off, the offending
> sensor needs replacing. And if the rotor has a lip, then the warning goes
> off early. Our sensors were bypassed by a PO long ago and not missed, it is
> easy enough to check the pads.
>
> Cheers, Jim
>
> ----- Original Message -----
> Date: Sat, 2 Sep 2023 15:41:45 +0000 (UTC)
> From: "mick cowles via " <mickcowles=[email protected]>
> To: [email protected]
> Subject: [PacNW928] Portland area meetup?, Brake pad questions
>
>? Michael B- It would be great to meet up sometime! I was thinking some
> Portland area meetups would make sense. Ken and I were talking about
> tinkering with the vacuum line on my automatic transmission. (Shifts hard
> when coasting in stop and go traffic). Also, I just shot Tom928 an email
> seeing if he might be interested in getting together for some projects. It
> would be cool if other Pacnw928 guys could join us, but it may not be
> practical due to the distance involved. I'm always happy to help people
> with 928 projects...heck, I don't even care if its a 928. I just enjoy
> wrenching and learning about mechanical stuff. Probably, the most urgent
> task on my shark is to swap out the rear brake pads. I've done brakes on
> Corollas, but never on a 928. Seems pretty straight forward. I'm down to
> 1-2 mm on those rear pads. When Ken took a peek at the rotors, he thought
> they might be good for one more set of pads. So I'd hate to score up these
> rotors by putting the job off too long. (Who knows if the brake pad sensors
> will work, right??)
>
> Pacnw928 guys- I could use some advice on choosing the right brake pads.
> I've driven a lot of beaters in my life, and the stopping distance of those
> cars was terrible, so anything I put in the 928 will be better than what
> I'm used to. I'm not racing, so I don't need to stop that quickly. Also, I
> don't care that much about dusting. I can't see thru to my calipers and
> rotors, so dust doesn't bother me. My priorities are a pad that won't eat
> my rotors quickly, and one that doesn't squeak. Any suggestions? Also, some
> advice about the best suppliers for 928 brake pads would be appreciated.
>
> Thanks!
> Mick
>
>? ? ? On Friday, September 1, 2023 at 04:29:51 PM PDT, Michael Benno <
> michael.benno@...> wrote:
>? Hey, all it was great to meet up with you all. Meet some new faces and
> reconnect with some old ones. Keith, you are a very generous host.
> Peter, I am so impressed with your 928 journeys!
> Mick, I am in Portland and would be happy to meet up whenever. Let me know
> it you need anything.
>
>
> On Fri, Sep 1, 2023 at 9:19?AM mick cowles via <mickcowles=
> [email protected]> wrote:
>
>? Peter- Glad you got the hood issue sorted out and got a chance to look at
> the timing belt. It was a pleasure meeting you and talking about 928's and
> wines! Let me know if that Malbec I gave you is any good.
>
> Andy- Thanks for taking the group photo. My sister and friends enjoyed
> seeing that. They've been following my journey with the 928 repairs since
> inheriting it, and were glad to see I got some help and have met some
> friends!
>
> Pacnw928guys- I mentioned getting together in the fall. I'll start
> rattling everyone's cages again in a couple months! If anyone is near
> Portland and needs help with anything before then, feel free email me or
> text at the number below.
>
> Best Regards,
> Mick Cowles
> (503) 484-4226
>
>? ? ? On Monday, August 28, 2023 at 09:26:33 AM PDT, Peter S s/v Dawa II <
> scottpeterd@...> wrote:
> It was great to finally put some faces to online names.? I had a great
> time.
>
> The run back gave me a chance to sort out the mixture on the CIS.? I came
> back up via 101/3 through Shelton.? Sunday was an antique car show, so I
> stayed a while.
>
> Ken:? stopped at Napa and got some lithium grease.? The bonnet now works!
>
> And thanks everyone for the help on adjusting the timing belt.
>
> Sadly, this was pretty much the last trip for the 928.? This weekend I
> leave for 2 months for sailing.
>
>
> Cheers
>
>
>
>
>
>
> --
> 1992 Porsche 928 GTS Japan market
>
>
>
>
>
>
>
> ----- End of Original Message -----
>
>
>
>
>
>
>
> --
> ---
> Gustatus Similis Pullus
>
>
>

--
---
Gustatus Similis Pullus






----- End of Original Message -----

One more input on Brake Pads - I've used a number of them and with all the changes I've done (from both track driving & street driving), I recommend 2 brands, but would choose Cobalt going forward:??

Cobalt:? A local Portland businessman - Eddie Nakato from AR Auto Service purchased Cobalt Brakes 2-3 years ago.? Eddie is a racer and has done work on my car before.? I've talked to Eddie about brake pads for my race car and he understands exactly what I need.? All the "track guys" I have talked to that have already used Cobalt say they are another world for feel and performance.? Cobalt does NOT show 928's on their web site, so would need a set of used pads to make new ones for you.? This is definitely the brand I am going with in the future.? For Street Use, they make a XR5 compound that is designed to replace the 1521 compound Carbotech I used on street before.? I would go with Cobalt XR5 for street use.??

Carbotech?- I had used these brakes for years with excellent success for wear, performance, and minimal dust.? The street compound is 1521 - S4 rear brakes is P/N CT345 (get 1521 compound) and S4 fronts are CT609.? The 1521 compound had zero squeaks (even without the non-squeak covers on the pistons) and were a great pad for the street with great braking performance.? Until there was Cobalt, I was firmly behind Carbotech.? Prior to these I had used Performance Friction (track compound) - they required so much brake pedal pressure I just about bent the steering wheel when on track.? I will never use them again.??

I have also used other pads on street & track, but the Carbotech was by far the best versus the previous.? However, for street going forward, I would use the COBALT XR5.? .??

Like others have said, changing the pads is very easy and above is a bunch of helpful hints on replacing them - pay special attention to not spilling the brake fluid out when pushing the caliper pistons back in - You need a pair of Channel Lock Pliers to open the Expansion Spring, then just either pull the pads out or push the pads (pistons) back a bit for clearance to pull the pads out.? ?

I changed pads so much I bought the neat Porsche recommended Hazet 4971-1 tool for pushing pistons back in.? If you want to do the job at my house, let me know & we can do it quickly.? ?

Regards,

Keith R. Martin

1980 Metallic Black 5 speed with S4 Brakes & other goodies.??