Brake fluid change

[1 old racer]

I was talking to some younger track whores, (under30). We were talking about what we do as far as track prep and we finally got around to brake fluid brand, grade and when we perform a brake fluid change out. We all pretty much agree on DOT 4 and everyone had their favorite brand. What surprised me is that I was the only one that does a complete fluid change every track event. What do you guys do?
They thought it was a good idea and they were really interested in my method. The method I use is the use different color fluid each time I bleed the system . The brands and color of my choice are, ATE-blue (dont ask how I still get it in the states) and the the ATE-gold, both dot 4. when I do, I bleed the system till I get a nice blue fluid out of each caliper or a nice clean gold. I do the same bleeding the clutch. Anyone else use this method?

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[Matti777]

That is or was a common method. I did a few club DE events and a brake flush was mandatory.

 

[boardkat]

if you have fluid with a very high wet boiling point (like castrol srf), there really isn't a need to flush anything other than your calipers between races.

 

[AlbertD]

I'm running Castrol SRF and flush once per season. Typically 18-20 track hours. Been doing that for years and have had zero issues.

 

[bnightstar]

I use Motul RBF660 and flush before every track day.

 

[Ewheels]

I second @Brian@BMVK , I bleed before each event.

 

[fatbillybob]

Doing brakes is like changing oil. When do you do it? People do oil after every race or track day too. I don't. I do it by oil test. Once I learn and confirm with oil test that's my personal frequency for that car under race conditions. Brake fluid testing isn't practical so you have to go with experience and what data you can gather formulating a plan. The blue gold ATE thing was in the past. Great idea if the fluid was robust but it really isn't. But if your brake system for how you drive is robust sometimes you can get by with a lesser fluid like the ATE. If your brake system is marginal for your use you might have to buy the expensive SRF. My vette racecar setup for SCCA T1 racing I could run a whole season and never even bleed the brakes because I never overheated the fluid and I could use cheapo valvoline brake fluid always found at the autoparts store. That's because the brakes were so robust.

I'm still learning the S550 only 4 races with a bunch of new untested go fast suspension parts so not sure on fluid management yet. There was one of the noted mustang racer vendors who ditched their 3" ducts for OEM tunnel rams and removing the inner front brake shield and got lower rotor temps than ducting. I'm using the non-ducted method and so far don't need to bleed after the weekend. But my new suspension parts should drop laptimes and put more heat into the brakes so we'll see where I am after some testing. There are good reasons to do a fluid change annually even if you don't track. If you are not boiling fluid that annual change should be all you need. If you need to bleed during the track weekend you need to improve the brake system to minimize that. If you are not needing to bleed because you didn't boil there really is no need to bleed between weekends except to make you feel better during your self-tech inspection that you are doing everything you can to have a safe functional car. That's reason enough to do it even if you really don't need to do it. My racecar does not use oil but I always check the level anyway. A prophylactic brake flush can be thought of that way.

 

[1 old racer]

Old habits do dye hard. I will try to talk myself out of doing this out of pure habit. But no promises.

 

[BimmerDriver]

If you do an event every weekend like i used to, then a monthly change is fine. If you do one twice a year, then change it twice, before each event.

I use ATE as well. How did you find the blue?

 

[Hack]

I don't do a complete flush. I want to make sure that the calipers don't have the same fluid in them for multiple events, but I don't think the fluid in the lines farther away from sources of heat needs to be purged.

However, I have to admit that I go with the better safe than sorry strategy for fluids. While I don't try to be absolutely sure every drop of brake fluid is purged, I probably go through more fluid when bleeding than just the amount in the calipers. I have a pressure bleeder and so I like to use up most of what I put in the bleeder. It's really easy to just leave the bleeder open a little longer and let a little more fluid through.

Same with oil and other fluids. IIRC Ford said in the GT350 to change after every event. So I did that. I will probably watch temperatures and decide what to do in my GT once I get to the track and see how things go. But most likely I will change fluids after every event.

 

[Hack]

I was talking to some younger track whores, (under30). We were talking about what we do as far as track prep and we finally got around to brake fluid brand, grade and when we perform a brake fluid change out. We all pretty much agree on DOT 4 and everyone had their favorite brand. What surprised me is that I was the only one that does a complete fluid change every track event. What do you guys do?
They thought it was a good idea and they were really interested in my method. The method I use is the use different color fluid each time I bleed the system . The brands and color of my choice are, ATE-blue (dont ask how I still get it in the states) and the the ATE-gold, both dot 4. when I do, I bleed the system till I get a nice blue fluid out of each caliper or a nice clean gold. I do the same bleeding the clutch. Anyone else use this method?

Do you actually disconnect the clutch line at the transmission and let it gravity bleed? I've never done this. Do you need to pull a vacuum on it afterwards to get the air out?

 

[BimmerDriver]

Do you actually disconnect the clutch line at the transmission and let it gravity bleed? I've never done this. Do you need to pull a vacuum on it afterwards to get the air out?

The slave cylinder should have a bleed nipple on it. You can let gravity do it, or pump the pedal.

 

[Hack]

The slave cylinder should have a bleed nipple on it. You can let gravity do it, or pump the pedal.

That's why I was asking. If you read the instructions from Ford, they say to hook a vacuum source up to the Master Cylinder (the clutch and brakes use the same fluid reservoir) and pump the clutch pedal to bleed the clutch. I did it before when I swapped transmissions on my GT350 tech pack over to the track pack transmission. As far as I can tell it's the same for a regular GT. I checked the shop manual again tonight and I didn't see anything about a bleed nipple on the slave. And Ford doesn't tell you to disconnect the line from the outside of the transmission case and let it gravity bleed either. Of course it has to be disconnected to swap transmissions and I did that. I got a good clutch pedal again afterwards using the vacuum technique.

So I'm always interested in what other people do. Seems like it's a pain if you want to get the fluid out of the slave cylinder as far as I can tell, so just wondering what I'm missing.

 

[BimmerDriver]

all of my previous cars had bleed valves, and I'm just assuming that the Ford does as well. I can't imagine how else you could get all of the air out.

That's why I was asking. If you read the instructions from Ford, they say to hook a vacuum source up to the Master Cylinder (the clutch and brakes use the same fluid reservoir) and pump the clutch pedal to bleed the clutch. I did it before when I swapped transmissions on my GT350 tech pack over to the track pack transmission. As far as I can tell it's the same for a regular GT. I checked the shop manual again tonight and I didn't see anything about a bleed nipple on the slave. And Ford doesn't tell you to disconnect the line from the outside of the transmission case and let it gravity bleed either. Of course it has to be disconnected to swap transmissions and I did that. I got a good clutch pedal again afterwards using the vacuum technique.

So I'm always interested in what other people do. Seems like it's a pain if you want to get the fluid out of the slave cylinder as far as I can tell, so just wondering what I'm missing.

 

[Hack]

all of my previous cars had bleed valves, and I'm just assuming that the Ford does as well. I can't imagine how else you could get all of the air out.

Vacuum at the reservoir opening and pump the pedal per the manual. It worked for me on a system that had been open for several weeks before being refilled with fluid.

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