Soft pedal

[mthreecpe]

Last track day the organizer threw the checkered about half way through the lap, so we only got a very short cool down. Aside from pad deposits (see other threads), the pedal felt consistent throughout the 20 minute sessions. After a session which had very little traffic, I drove around the paddock for ~5 minutes to try and make up for the very short cool down lap. Ended up having the pedal go to the floor as I coasted into my parking spot in the paddock.

I assume this was heat soak from the calipers which caused the fluid to boil after the session? Also, what warning signs should we get on track that the fluid is getting hot...i.e. softer pedal? And, are there any other mechanical points of failure in the system to be aware of?

Fluid was a premium track-capable fluid per the shop...probably don't see many track cars at that shop.

[slcook54]

I'm assuming you're on stock brakes and castrol SRF or some equivalent. There have been a few who have had some success with modified stock systems in cooler temps, but the vast majority of folks tracking with the stock system experience what you did. My pedal went 1/2 way to the floor my first track day at Laguna. These are heavy cars with mediocre brakes. They are fine for a couple hard stops on the street, but won't hold up to 20 minute sessions on the track. I view the BBK as a safety item for tracking this car.

It doesn't really make sense, in my opinion, to chew through the stock system and keep replacing it.

My vote is for the Essex AP kit.

[mthreecpe]

Did you get some warning signs that the pedal was getting softer?

I was on track pads with a fluid that probably wasn't up to the the task.

My question basically is if the OEM system with track pads and fresh track fluid will at least give warning of either pad or fluid issues or if others have experienced a cliff.

[roastbeef]

the oem system is garbage. the warning signs will be a gradually softer pedal. the depth of the press may be gradual, so don't let that fool you until its too late. its gradual, but once the fluid is boiled, its going to feel "all of the sudden." if you're going to limp along an oem brake system, you need to include some cool down laps and significant time rolling around the paddock if the session is stopped abrubtly.

[Estoril Blue]

Originally Posted by mthreecpe

Fluid was a premium track-capable fluid per the shop...probably don't see many track cars at that shop.

Opinion: If the shop actually said that - then:

1. It was probably shyte fluid.
2. You shouldn't use that shop.

Better: You bring Castrol SRF and specify your fluid. Don't let a shop without concrete and current track credentials use mystery fluids, pads or components on a tracked car.

Your system needs a full flush now. Full.

Recommendation: Once you see a checkered flag - go "no brakes" and manage your speed to the next turn. That doesn't mean crawl.

Which pads are you using?

[roastbeef]

all brake fluid is track capable. just depends on how many minutes you want it to be capable for.

[dparm]

Originally Posted by mthreecpe

I assume this was heat soak from the calipers which caused the fluid to boil after the session? Also, what warning signs should we get on track that the fluid is getting hot...i.e. softer pedal? And, are there any other mechanical points of failure in the system to be aware of?

I would agree with this assessment. And yes, as the fluid gets hot you will notice longer pedal travel during the session.

The stock brakes don't have a ton of cooling so as you get faster (and run stickier tires), you will need to manage your brakes a bit. A BBK will provide a lot more endurance, lighter weight, and faster pad changes. It might even drive consumption costs down a bit over time.

Not having to worry about your brakes every time you approach a braking zone will make track days much more fun.

[Move Over]

Originally Posted by roastbeef

all brake fluid is track capable. just depends on how many minutes you want it to be capable for.

1 press of the pedal or 500 presses

[sbo76]

Originally Posted by mthreecpe

Did you get some warning signs that the pedal was getting softer?

I was on track pads with a fluid that probably wasn't up to the the task.

My question basically is if the OEM system with track pads and fresh track fluid will at least give warning of either pad or fluid issues or if others have experienced a cliff.

Hmmm - I run EBC Yellow, Motul brake fluid and stainless steel brake lines on a pretty stock car (200 tread wear tires, stock suspension, etc). I have not had full brake fade yet. Which pads and fluid are you running? I don't push this car as hard as i do my race prepped e46 but i am braking hard and hitting relatively fast times for what it is.

[tdott]

I've done flushes after a few shops supposedly did them.

Guess what, most of them lied, or barely did anything (few quick bleeds, then top off).

Learn to do it yourself. Vacuum or suction out the reservoir with a syringe and thoroughly flush each line. You'll go through atleast 1L if you did it right.

I use cheap ate200 fluid, fresh for every track day without issue, yet a few guys that supposedly have SRF fluid have had brake issues on track days with me. Plus they run slower laptimes. One melted a caliper piston.

I showed one guy what his fluid looked like and there was no way it was done properly before his track day.

[dogbone]

Originally Posted by tdott

I use cheap ate200 fluid, fresh for every track day without issue, yet a few guys that supposedly have SRF fluid have had brake issues on track days with me. Plus they run slower laptimes. One melted a caliper piston.

If I may ask----how many track days do you do in a year? And when you say you put fresh fluid every track day, what happens if you attend a track weekend? Do you literally mean EVERY track day? So you have to bleed at the end of Saturday in preparation for Sunday? Or do you leave it in the whole weekend? And are you doing a minor bleed just to refresh mainly what is in the caliper? Or are you completely flushing it every time?

For me, putting fresh brake fluid every track day is just not practical. I can leave SRF in the system for a year without issue. I never have a soft pedal. Of course, I also give credit to the AP kit for being able to dissipate heat quite efficiently.

[tdott]

Originally Posted by dogbone

If I may ask----how many track days do you do in a year? And when you say you put fresh fluid every track day, what happens if you attend a track weekend? Do you literally mean EVERY track day? So you have to bleed at the end of Saturday in preparation for Sunday? Or do you leave it in the whole weekend? And are you doing a minor bleed just to refresh mainly what is in the caliper? Or are you completely flushing it every time?

I don't do that many days. Usually 3-4 plus a few autocross, except for 2020 which I only got 1 track day and 1 autocross in. I do it as part of pad swap, street wheels to track wheels, vehicle check, etc. It's been a while since I've done both days on a weekend, I don't usually do back to back days, but I don't think I'd have a problem. I usually do more than a minor bleed, siphoning out the reservoir and trying to flush the line/caliper a bit.

Since you are tracking often enough and using a high quality fluid you shouldn't have any problem doing a less than full flushes, I'm sure your fluid is staying fresh enough.

My comments were more towards those who are new to tracking, if the car hasn't gone through much maintenance and the brake fluid is probably several years old. Then they take it to a local garage, chances are pretty low they are going to get a really well done flush. Now that is not to say there aren't a few good shops out there that I'm sure can be trusted to do a good job. It's just I worked in the industry and I know the short cuts the mechanics will take when they are getting paid flat rate.

A friend I made recently had this happen, he provided SRF to a shop that did his prep before his track day which we attended together, his car is stock except for wider wheels/tires and lowering springs, even his exhaust was still stock. Yet he over heated his brakes at Sebring (pretty hard on brakes) warped brand new FCP rotors new from a few weeks before and had soft pedal issues. It wasn't a pad deposit issue. There was still a lot of vibrations under braking after re-bedding and hard stops after the track day and it got worse.

Since we became friends, I helped him install new rotors/pads as they were covered from fcp and did a brake fluid flush with SRF. What came out was certainly not fresh fluid. I even made sure we did the DSC activation/bleed procedure using ISTA. That takes time and unless a shop is charging you 1-2 hours of labor I doubt they are doing it fully.

He went on to do two track days after that and his brakes held up much better.

[dogbone]

Originally Posted by tdott

I don't do that many days. Usually 3-4 plus a few autocross, except for 2020 which I only got 1 track day and 1 autocross in. I do it as part of pad swap, street wheels to track wheels, vehicle check, etc. It's been a while since I've done both days on a weekend, I don't usually do back to back days, but I don't think I'd have a problem. I usually do more than a minor bleed, siphoning out the reservoir and trying to flush the line/caliper a bit.

Since you are tracking often enough and using a high quality fluid you shouldn't have any problem doing a less than full flushes, I'm sure your fluid is staying fresh enough.

My comments were more towards those who are new to tracking, if the car hasn't gone through much maintenance and the brake fluid is probably several years old. Then they take it to a local garage, chances are pretty low they are going to get a really well done flush. Now that is not to say there aren't a few good shops out there that I'm sure can be trusted to do a good job. It's just I worked in the industry and I know the short cuts the mechanics will take when they are getting paid flat rate.

A friend I made recently had this happen, he provided SRF to a shop that did his prep before his track day which we attended together, his car is stock except for wider wheels/tires and lowering springs, even his exhaust was still stock. Yet he over heated his brakes at Sebring (pretty hard on brakes) warped brand new FCP rotors new from a few weeks before and had soft pedal issues. It wasn't a pad deposit issue. There was still a lot of vibrations under braking after re-bedding and hard stops after the track day and it got worse.

Since we became friends, I helped him install new rotors/pads as they were covered from fcp and did a brake fluid flush with SRF. What came out was certainly not fresh fluid. I even made sure we did the DSC activation/bleed procedure using ISTA. That takes time and unless a shop is charging you 1-2 hours of labor I doubt they are doing it fully.

He went on to do two track days after that and his brakes held up much better.

Glad you were able to help your friend. I just had my first flush done this summer using ISTA procedure. Was interesting.

[Move Over]

Here's a great article on brake fluid.

https://www.essexparts.com/news-blog...ng-brake-fluid