[Kmeleon]

Originally Posted by TheRealJA105

I don't think anyone really knows. You need to know the length and the inside diameter of each brake line to calculate the volume and you would also need to know the volume in each caliper. Basically bleed alot and waste alot of new to make sure you get all the old out. Suck out the master with a baster/syringe and refill with the new fluid first so you don't have to push all that old stuff in the master out too.

Then you will hear you have to activate ABS solenoids to get everything out of there, but I've never done that and you need the dealer tool for that.

Sucks to waste fluid especially the expensive SRF, but I've seen some people say that the total capacity is less than 1L and some say it's more so that is why i say just do alot

If they allowed colored fluid anymore that would be nice.

I was afraid that was the answer I'd get

[Kmeleon]

Originally Posted by rotis

For the first flush I did, I put fluid in the motive. It was nice being able to fairly quickly go around to each caliper and bleed without worrying about the master running dry. I was also a bit paranoid about it leaking and blowing fluid everywhere, so I had my kid watching the MC to be sure it didn't get out of hand.

It was a bit annoying to clean all the fluid out of the motive afterward, using denatured alcohol and then making sure it was properly dry before putting it away.

Just from the annoyance of cleaning it, I switched to using it dry without fluid. Now I just use it to pressurize the MC and pull the cap to add fluid between corners.

That's a big Pro towards using it dry right there, I never even thought about cleaning it. I'm sure it's a PITA. I'm going to use it dry.

[Pcormier66]

Fresh fluid is rated at the dry boiling point. Over time, and depending on exposure, the fluid absorbs water and the boiling point drops dramatically to it's wet boiling point. It doesn't take long to contaminate fluid. For example:

Fluid Dry Boiling Wet Boiling
Motul 660 617 400
Motul 600 594 401
Brembo HTC 64T 635 397
SRF 608 518

The primary reason people have good luck with SRF is because it is less hygroscopic than conventional brake fluids - it absorbs less water over a given time. Conventional fluid can absorb moisture sitting on a shelf. The more important number is wet boiling if you don't plan to change often. If max dry boiling is important, be prepared to change the fluid regularly.

The negative with SRF is that some of the moisture it is exposed to is not absorbed by the fluid and can remain suspended in the brake system and can become corrosive. You need to change SRF every year. Conventional fluid is designed to resist corrosion and can sit in the system for much longer periods. but it will be reduced to it's wet boiling point

Like everything related to tracking a car, there are trade-offs.

I like Brembo HTC 64T for its low compressibility and high dry boiling point. Gives you a firmer pedal. But I will be changing it a lot more frequently due to it's relatively low wet boiling point.

Link to a comparison of all the major brands:
https://thebuildjournal.com/tech-gui...view-analysis/

[cdb95z28]

I run my Motive dry. Just pay attention to the MC, that's all. Before removing the MC connection, bleed off the pressure at the Motive, otherwise you'll get brake fluid wanting to spray everywhere. Take your time and pay attention to the details.

Set aside plenty of time to work on your brakes. And don't look to bleed/flush the evening before a track day unless you are prepared to deal with unforeseen problems. Like a broken bleeder. Get spares. Spare bleeders, banjo bolts, copper washers. Do not rush working on cars. Especially working on cars that will be run to their limits.

I do a full flush at the beginning of the season, then an easy "burp" before an event. A burp being just a short bleed to push a bit of fluid thru the caliper. Obviously, the highest stressed fluid is going to be in the caliper, so pushing out the caliper fluid is a good thing. I maybe get about a 1/3 to a 1/2 cup out total with each burp of all four calipers. I used to use SRF, now I use HTC 64T, better pedal feel and no hot compressibility that SRF can bring.

I focus more burp on the fronts as the rears don't see the same stress. But if you are using your stability/traction control on track then the rears will see more stress than not using it. As for the ABS cycling, once you engage the ABS while driving you'll be mixing/moving that captured fluid. Eventually after a few bleeds/ABS use it's pretty much a non issue. The ABS unit is not seeing the heat stress like the calipers do. I can see wanting to remove that small amount of captured fluid after a DOT3 to DOT4 change over or due to a contaminated fluid issue though.

After doing bleeds enough you'll get a feel for how much fluid you can bleed out that equals the caliper volume.

I store my fluid in multiple heavy duty zip lock bags with desiccant pellets and a hygrometer in my humidity controlled basement family room. Since I do the burps, I only use as much fluid as needed. Yes, I open a container and keep using it throughout the season. But since I keep it in a low humidity environment, I'm confident in its integrity.

[cdb95z28]

Originally Posted by TheRealJA105

I don't think anyone really knows. You need to know the length and the inside diameter of each brake line to calculate the volume and you would also need to know the volume in each caliper. Basically bleed alot and waste alot of new to make sure you get all the old out. Suck out the master with a baster/syringe and refill with the new fluid first so you don't have to push all that old stuff in the master out too.

Then you will hear you have to activate ABS solenoids to get everything out of there, but I've never done that and you need the dealer tool for that.

Sucks to waste fluid especially the expensive SRF, but I've seen some people say that the total capacity is less than 1L and some say it's more so that is why i say just do alot

If they allowed colored fluid anymore that would be nice.

Lol, I used to use the ATE Super Blue and the regular ATE amber back in '08 in my '95 Z28. I knew when I had pushed enough fresh fluid. I drove my old Z in WV back in 2019 and it still had the Super Blue from when I sold it in '09 and the pedal felt amazing!

[weemus]

SRF all the way. I only change once a year because I want to enjoy the car not speed bleed between sessions. I would take note of anything that requires or potentially requires work while at the track. We pay a lot of $$$ to track anything that can potentially cause an issue over a weekend or god forbid ruin the weekend just isn’t worth it.

[MatthewAMEL]

Swapped to stainless brake lines today...thought I would take a quick clip of using the MityVac to bleed the brakes.


https://youtu.be/L4KQIJ1yWXA

[20Bluezl1]

Originally Posted by MatthewAMEL

Swapped to stainless brake lines today...thought I would take a quick clip of using the MityVac to bleed the brakes.


https://youtu.be/L4KQIJ1yWXA

You might be the first video on YouTube to brake bleed with the MityVac. I wish there was a way to prevent air from the fitting so it doesn't look like if you where removing air. Good job

[MatthewAMEL]

Originally Posted by 20Bluezl1

You might be the first video on YouTube to brake bleed with the MityVac. I wish there was a way to prevent air from the fitting so it doesn't look like if you where removing air. Good job

I guess I just have gotten used to it. The moment you see ANY fluid in the tube, you are pulling it from the caliper. I'm not sure if you saw the reservoir in the video, but that was the amount I pulled doing the whole vehicle.


It's a great multi-purpose tool. I also did my oil and diff today and used the MityVac for both.


The Motive is a great product and it's pretty easy to bring track-side if you are going to be running HPDE. I also had better luck with my Motive dry.

[Texan4iu]

For those tracking their car and using Brembo HTC64, how often are you bleeding it? I recently switched from Endless to Brembo, so I wasn't sure if Brembo needed to be bled every couple of track days, or if it was good for several days. Thanks in advance!

[TrackClub]

Originally Posted by Texan4iu

For those tracking their car and using Brembo HTC64, how often are you bleeding it? I recently switched from Endless to Brembo, so I wasn't sure if Brembo needed to be bled every couple of track days, or if it was good for several days. Thanks in advance!

No experience with Brembo, but just fyi SRF didnt require any bleeding for a season, while Willwood EXP (which I liked a lot performance amd price wise), required a bleed every 5 days or so. Hopefully somebody will chime in with your fluid experience, but you may try bleeding at say 4 days and see what results you get. If it comes out pretty clean, it was too soon Cheers!

[Texan4iu]

Originally Posted by TrackClub

No experience with Brembo, but just fyi SRF didnt require any bleeding for a season, while Willwood EXP (which I liked a lot performance amd price wise), required a bleed every 5 days or so. Hopefully somebody will chime in with your fluid experience, but you may try bleeding at say 4 days and see what results you get. If it comes out pretty clean, it was too soon Cheers!

LOL. Thx for that.