[GriffW]

Hey guys,

I’m running into some problems that I’m currently stumped on and would love some thoughts on.

I have a 2020 SS 1LE that is at 20760 miles ish. I got it back in May of 2020 new. I’ve loved the car. My first track day will be in late October of this year. I’m sad this is the first time I’ve been able to take it out. My braking system has been stock up until this year. Ive done some hard braking events to be familiar with the capabilities of the car and driving hard here and there up until March of this year. The car felt great in general under braking, one thing I wanted was a higher and sharper bite point on the pedal but that was about it.

It was around this time I felt some reduced braking performance where my braking distance seemed to increase and my performance deeper into the pedal was sub par from where it used to be. After talking to a friend, I swapped out my fluid for Castrol SRF. I put in about 1.2L on March 9th (9.9k miles). This seemed to help. But during high speed braking (from 120) braking was a little squirrelly. Not dangerous but a little odd.

I then got some Gloc GS1s. Installed those July 18th (17.5k miles)I also flushed an additional 0.8L of fluid around this time as well but I forgot to document that. They had more confidence than the stock pads for sure especially at high speed braking, and I was quite happy. I did a little brake in procedure, nothing scientific just hard stops to where I could smell the pads.

Aug 7 I applied some brake system grease from CRC to the back of the GS1 pads. They were doing some squeaking with turns under no braking and now power. The squeaking did go away. I would expect that I probably applied more than needed. But I don’t think it was a ton.

We learned, from another car, that the GS1s were not the compound we originally thought they were and that under track use they would fade quickly and I should go back to stock or get some other compound.

I found a forum member here selling his Gloc R10s with only one track day on them. I installed those pads on Sept 11 at 20269 miles. They had a ton of material left and looked to be in good order. I did apply brake grease to these pads too. But probably a smaller amount than what was put on the GS1s. After install the pedal feel was worse than the GS1s and stock and seems to have poorer braking performance. This was discovered when I went to do my non scientific bead in procedure. Where id start braking at say 60% pressure and it would hold there for a second then the pedal would sink deeper down to say 80%. This is course led to poor braking performance. The brakes did start to make more noise, which to me was a good sign in that the new pad seems to be making better contact with this rotor resulting in more noise, and likely transferring more material.

After talking with some others I decided to flush more fluid which I did yesterday. About 0.8L. I had no change in pedal feel or really performance. I went out and did some more hard braking yesterday. More than I have done before. But did not again follow that exact procedure. I did have moments of very good performance and better pedal feel. But it never stuck.

I still feel like it could be that these pads are still not bedded on and what I am experiencing is the different pad materials, and maybe a proper bedding procedure would fix this. I also feel like maybe that grease could be affecting things but I don’t know. I also have not driven the car yet after yesterday so maybe it’s all fixed.

I am curious to hear other’s thoughts and experiences on this.

[5.M0NSTER]

How are your front tires? Sounds like you could be just getting into ABS due to poor tire grip.

I've used Carbotech/GLOC 8s, 10s and 12s. No issues like this after proper bed in. Currently on Hawk DTC60s and also all good. During bed in you don't get good feel or bite. You have to follow the procedure, then let it cool to ambient before the grip comes in.

[kropscamaro16]

Originally Posted by 5.M0NSTER

How are your front tires? Sounds like you could be just getting into ABS due to poor tire grip.

I've used Carbotech/GLOC 8s, 10s and 12s. No issues like this after proper bed in. Currently on Hawk DTC60s and also all good. During bed in you don't get good feel or bite. You have to follow the procedure, then let it cool to ambient before the grip comes in.

yup i have same pads on my car with goodridge ss lines and motul 660 fluid no problems

[khcoaching]

I ran mine with stock pads and Castrol SRF and had zero issues. I swapped to Ferodo DS1.11s and have saw a massive improvement, still on the same fluid. I would never use brake grease....

Did you do an entire system flush all at once? Did you bed the pads in correctly? As much as it sucks, I would get new pads and try bedding them in correctly.

Ken

[Norm Peterson]

Originally Posted by 5.M0NSTER

How are your front tires? Sounds like you could be just getting into ABS due to poor tire grip.

I've used Carbotech/GLOC 8s, 10s and 12s. No issues like this after proper bed in. Currently on Hawk DTC60s and also all good.

Same experience here on my GT (which has been tracked on its little OE 12.4"/11.8" rotors). Same three compounds, all three of which are pretty gentle as far as rotor wear rates are concerned.

During bed in you don't get good feel or bite. You have to follow the procedure, then let it cool to ambient before the grip comes in.

Driving a few miles doing as little braking as possible is probably the best way to ensure even cooling of everything you just made hot.


GS1 or Carbotech 1521 is a daily-driver compound with a hint of improved braking performance over many OE compounds. Our WRX is getting 1521s very shortly for improved bite over its OE pads in moderate to moderately hard stops in street driving, had them on another car before.


Norm

[weemus]

I've ran the Carbotech 1521's on my WRX and while good for the street, track pads they are NOT. Only good for a non tracked daily and autocross.

+1 on SRF. Its the best and doesn't require bleeding between events.

To my next question, are you following the proper bleed procedure on the calipers? Not just which brake to start with but also which bleeder to start with? Cant recall the procedure off hand.

[Norm Peterson]

Originally Posted by weemus

I've ran the Carbotech 1521's on my WRX and while good for the street, track pads they are NOT. Only good for a non tracked daily and autocross. \

Precisely.


Norm

[GriffW]

Originally Posted by 5.M0NSTER

How are your front tires? Sounds like you could be just getting into ABS due to poor tire grip.

I've used Carbotech/GLOC 8s, 10s and 12s. No issues like this after proper bed in. Currently on Hawk DTC60s and also all good. During bed in you don't get good feel or bite. You have to follow the procedure, then let it cool to ambient before the grip comes in.

Fronts are good. Lot of tread life left of the PS4Ss. I do feel like it is the bed in. All rotors look like they have an uneven pad transfer. I think I need to find a better place to bed in to get back to back stopping to continue increasing the heat load on the system. Bedding in the GS1s were quick and didn't take a whole lot of effort. I should have expected the R10s to need a little more work.

Originally Posted by weemus

I've ran the Carbotech 1521's on my WRX and while good for the street, track pads they are NOT. Only good for a non tracked daily and autocross.

+1 on SRF. Its the best and doesn't require bleeding between events.

To my next question, are you following the proper bleed procedure on the calipers? Not just which brake to start with but also which bleeder to start with? Cant recall the procedure off hand.

I believe so. Always starting from inside valve to outside, and working from furthest from master cylinder to closest

[Dabjbr]

Originally Posted by GriffW

I believe so. Always starting from inside valve to outside, and working from furthest from master cylinder to closest

Although I don’t believe brake bleeding is the problem, you have the sequence wrong.

In most cars, it starts with the RR and ends with the LF. In the camaro, the order is based on diagonals. There’s a DIY on here that speaks to it.

[kropscamaro16]

the first time i got my ss lines on and brake fluid replaced the shop had a hell of a time getting all the air out they had to do it like 3 or 4 times lol i would take it to a shop to have them check it out

[weemus]

Originally Posted by Dabjbr

Although I don’t believe brake bleeding is the problem, you have the sequence wrong.

In most cars, it starts with the RR and ends with the LF. In the camaro, the order is based on diagonals. There’s a DIY on here that speaks to it.

Here it is, follow this:

Originally Posted by MatthewAMEL

Actually the service manual says:


RR, LF, LR, RF


Fill the brake master cylinder reservoir with GM approved brake fluid from a clean, sealed
brake fluid container. Ensure that the brake master cylinder reservoir remains at least half-full
during this bleeding procedure. Add fluid as needed to maintain the proper level.
Clean the outside of the reservoir on and around the reservoir cap prior to removing the cap
4.
and diaphragm.
Install a proper box-end wrench onto the RIGHT REAR wheel hydraulic circuit, inboard (fixed
caliper), bleeder valve.
5.
Install a transparent hose 6. over the end of the bleeder valve.
Submerge the open end of the transparent hose into a transparent container partially filled with
GM approved brake fluid from a clean, sealed brake fluid container.
7.
Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the
pedal.
8.
9. Loosen the bleeder valve to purge air from the wheel hydraulic circuit.
10. Tighten the bleeder valve, then have the assistant slowly release the brake pedal.
Wait 15 seconds, then repeat steps 8-10 until all air is purged from the same wheel hydraulic
circuit.
11.
12. For fixed caliper models, repeat steps 5-11 for the outboard bleeder valve.
With the right rear wheel hydraulic circuit bleeder valve, or valves (fixed caliper), tightened
securely - after all air has been purged from the right rear hydraulic circuit - install a proper
box-end wrench onto the LEFT FRONT wheel hydraulic circuit, inner (fixed caliper), bleeder
valve.
13.
14. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
15. For fixed caliper models, repeat steps 5-11 for the outboard bleeder valve.
With the left front wheel hydraulic circuit bleeder valve, or valves (fixed caliper), tightened
securely, after all air has been purged from the left front hydraulic circuit, install a proper
box-end wrench onto the LEFT REAR wheel hydraulic circuit, inner (fixed caliper), bleeder
valve.
16.
17. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
18. For fixed caliper models, repeat steps 5-11 for the outboard bleeder valve.
With the left rear wheel hydraulic circuit bleeder valve, or valves (fixed caliper), tightened
securely, after all air has been purged from the left rear hydraulic circuit, install a proper
box-end wrench onto the RIGHT FRONT wheel hydraulic circuit, inner (fixed caliper), bleeder
valve.
19.
20. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
21. For fixed caliper models, repeat steps 5-11 for the outboard bleeder valve.
After completing the final wheel hydraulic circuit bleeding procedure, ensure that each of the 4
wheel hydraulic circuit bleeder valves, or 8 bleeder valves (fixed caliper), are properly
tightened.
22.
Fill the brake master cylinder reservoir to the maximum-fill level with GM approved brake fluid
from a clean, sealed brake fluid container.
23.
24. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.

Do another bleed following this to a T. See how it goes. The sequence ensures the ABS circuit is devoid of air.

[GriffW]

Originally Posted by weemus

Here it is, follow this:


Do another bleed following this to a T. See how it goes. The sequence ensures the ABS circuit is devoid of air.

Thanks I will also try this when the SRF comes in.

I attempted a more complete bedding procedure last night. But about every spot I went to I ran into a surprising amount of traffic. Started the procedure about 4 times to be stopped. Bedding is not complete. But brakes felt a ton better and it looks like the pad layer is increasing on the rotors but not completely done. I looked online for some pictures of partially bedded rotors didn’t find a ton, but that’s what it looks like. Pictures are of RR and LF with indirect and direct light. I aim to go out again with some further road recommendations from others.

[GriffW]

I also saw on the forums in a post I do not recall, someone was saying if your brake pedal sinks on vehicle start you have air in your brake system. It doesn’t sink to the floor or anything it just moves down a little bit in the travel, from where you held it to start the vehicle to the vehicle on. Does anyone have any thoughts on that? Does everyone’s pedal sink on start up or was that statement correct?

[weemus]

Never heard anything about this pedal sinking theory.