Brake Fluid thread

[Burla]

So what interval do we think we should be on? Most places say 2 years, but is that realistic? You see how dark even 30k mile fluid gets, while a 2 year interval seams pretty reasonable, I just don't know that is realistic in real world life. One good thing about the ram is the size of the oil reservoir above the master cylinder. So you can easily take out 16 ounces even with a turkey baster and put back a fresh pint of dot 4. Now, I'm not saying this is a good way to go about it, but I don't judge, and seeing on how much detail goes into a true brake fluid change, as an option wouldn't that be better then nothing? And maybe you have a 4 year interval on full brake fluid flush, but every other year at least drain the cup and put back in fresh? Just trying to come up with real world options. I say do the flush, but I say do a reservoir swap if you arent gonna do a full flush. People are busier then ever, it is good to have options, it is very easy to swap reservoir. Guys on a heavy duty schedule towing heavy, you need to bare down and get it done, but for other guys, at a minimum you can drain/fill. It is likely the easiest thing you can do in vehicle maintenance.

 

[Mister Luck]

I believe the “high performance” groupies would appreciate another aspect on brake fluid composition and selection.

You should ask questions:
How does my driving affect the quality of my fluid?
Is it really necessary to use a higher grade fluid or do I need to change my brake fluid more frequently?
What is the difference between Dot 3 and Dot 4 brake fluid?

Following are specifications for some of the major brands of performance brake fluids:

Dry Boil Wet Boil

Brand/Model Point (°F) Point (°F)

AP Racing 550...............................550.....................284

AP Racing Super 600......................572.....................311

ATE Super Blue Racing DOT 4..........536.....................388

ATE Type 200 DOT 4......................536.....................388

Brake Man Hi Temp 577 Fluid..........577.....................300

Castrol LMA DOT 3 & 4...................446.....................311

Castrol SRF...................................590.....................518

Ford Heavy Duty DOT 3..................550......................290

Motul Racing 600...........................585......................421

Sierra SRP Z-10.............................570.....................N/A

Wilwood EXP600 PLUS....................626.....................417

Wilwood Hi-Temp 570.....................573.....................313

'Bright Idea' For Short Detection | MOTOR

Brake fluid seems to be an almost forgotten aspect of performance vehicle preparation and maintenance. Too many enthusiasts (and even many racers) tend to “fill it and forget it.” Yet brake fluid—both the type and the condition—is critical to dependable and consistent braking performance. For...

www.motor.com

 

[HEMIMANN]

Service intervals for hygroscopic brake fluids are 2-3 years. I usually just change when brakes start to get spongy, which is a gradual pedal softening between years 2 & 3. Has little to do with mileage, more to do with how dry your climate is.

Peeps from western US are always surprised how humid the upper midwest gets.......when winds blow from the south, we get direct Houston airflow. We get as tropical as Houston whenever this happens - I know brake systems are "sealed", but no seal is perfect.

 

[BLUKTY2]

Good thread- thanks for starting it Burla.

I change the brake fluid in all of my vehicles about every two to three years. The fluid is cheap and the process is easy. Don't even need to jack up any of my vehicles. I have my wife work the brake pedal while I work the bleed nipples. It goes so smoothly that we are still speaking to each other when the process is completed!

I use whatever fluid is recommended by the manufacture and I do not mix DOT 3 with 4 or 5.1.

It seems to me that on these vehicle forums so much attention is placed on engine oil and maintenance, transmission fluid and maintenance, etc. but brake maintenance is rarely mentioned in comparison. Personally, I greatly value my vehicles brakes and like to keep them in good working order.

 

[turkeybird56]

With all due respect, Dot 3 and Dot 4 are not compatible. While Dot 4 is backwards compatible (Higher dry/wet boiling point), Dot 3 can not be used in a Dot 4 system. In a brake system with high heat characteristics the Dot 3 (brake fade) will boil, trapping air in the system, causing brake failure. The low viscosity Dot 4 is necessary for vehicle with ABS and traction control systems. The advice for any fluids or maintenance for your vehicle is to refer to your owners manual or service manual for the correct fluid type and specifications. If you would like to know how much water is in your brake fluid, use a volt meter. Put the positive in the brake fluid and the common on battery negative. .1 mV = 1% water and 300 mV or 0.3 mv is 3% water. The maximum specification for water in a brake system is 3% water.

Good info there, had to save in my other misc folder ref info, just in case.

 

[Burla]

Good thread- thanks for starting it Burla.

I change the brake fluid in all of my vehicles about every two to three years. The fluid is cheap and the process is easy. Don't even need to jack up any of my vehicles. I have my wife work the brake pedal while I work the bleed nipples. It goes so smoothly that we are still speaking to each other when the process is completed!

I use whatever fluid is recommended by the manufacture and I do not mix DOT 3 with 4 or 5.1.

It seems to me that on these vehicle forums so much attention is placed on engine oil and maintenance, transmission fluid and maintenance, etc. but brake maintenance is rarely mentioned in comparison. Personally, I greatly value my vehicles brakes and like to keep them in good working order.

This is true and something maybe some people don't realize, you don't need to take off tires for brake bleed or even jack it up, what helps a lot is to have a longer bleed tube, run the tube out a bit, keep it wet is all you need.

 

[Mister Luck]

I appreciate the chance to read different opinions on brake fluid use.
I have decades of driving experience of 200 plus miles daily through which I supported my full time formal education as an automotive specialist My daily drive was what many would consider treacherous at best and I clearly understand the limits of mechanical physics, in which driving is not all accelerator and brakes, of course the manual transmission still survives the growing technological stage of green politics but those who haven’t had the opportunity to drive a manual clutch will still understand the necessity of gear ratio and the dynamics of velocity as it plays in forward momentum . The more control you have over your transmission and horsepower to weight ratio of your vehicle the less braking energy you will need to consume. If your transmissions computer is not down shifting on cue from the input of your sensors or the weight at which you tow your cargo or trailer is at or above it’s limits , brake fluid is not going to be that margin between you and disaster from brake failure.
I now live in a northern latitude that demands even greater attention to maintenance and safe driving practices where many vehicles greatly outweigh mine and travel at nearly twice my speed on roads that make my previous experiences look like a Sunday hayride.
Yes I’ve upped my game, no I haven’t forgotten basics because mistakes are not as forgiving now. I’m more gentile now as I age and my reactions to criticism are less about my pride and more about how I can communicate more affectively to dispel ignorance and inexperience.

 

[Livinalittle]

I am also guilty of neglecting my brake fluid. I just changed mine this summer and it was well overdue.

I apologize that this post is not specific to brake fluid but I do think it's relevant. If not please feel free to delete it.

I only recently learned about reverse brake bleeding but I was pretty impressed after trying it. I still vacuum bled to change out the fluid, but finishing off with a reverse bleed was a simple one-person operation that left me with a very solid brake pedal and no second-guessing.

This is where I first heard about it, again I apologize is this is old news for you guys. https://www.brakebleeder.com/solutions/bleeding-brakes/bleeding-methods/

Cheers

 

[Mister Luck]

I am also guilty of neglecting my brake fluid. I just changed mine this summer and it was well overdue.

I apologize that this post is not specific to brake fluid but I do think it's relevant. If not please feel free to delete it.

I only recently learned about reverse brake bleeding but I was pretty impressed after trying it. I still vacuum bled to change out the fluid, but finishing off with a reverse bleed was a simple one-person operation that left me with a very solid brake pedal and no second-guessing.

This is where I first heard about it, again I apologize is this is old news for you guys. https://www.brakebleeder.com/solutions/bleeding-brakes/bleeding-methods/

Cheers

The main benefit of reverse bleeding is to remove air from a brake system that uses silicone fluid DOT 5 When used on a glycol based system you run the risk of pushing a large percentage of the contaminants back up into the hydraulic system. Those reverse bleeder setups are not cheap either.
If you have problems getting a firm petal feel with conventional methods maybe you need a better vacuum system or utilize the computer actuation after conventional bleeding .

 

[Sherman Bird]

Only if you have DOT 5 in now. Silicone is completely incompatible with glycol ether.

NEVER put silicon brake fluid in a system with ABS!!!!!!!