How often should this be changed?

I was planning on going with a DOT4 fluid but was talking with a friend recently who told me that if I use DOT 4 it has a higher temp resistance but will also need to be replaced more often due to the fact that is absorbs water easier than DOT 3 fluid. Is this true? Should I stick with DOT 3 since I dont see the track very often? Whats the best DOT 3 fluid to use? OEM?

 

Dot 3/4 is typically OEM blend. unless you see alot of track time, 3/4 mix is fine.
otherwise motul brake fluid is aparently 'teh win'

i currently use valvoline dot 3/4 brake fluid.

 

I'm using the Valvoline SynPower DOT3/4 fluid as well. The Valvoline has a higher BP than OEM fluids but not as high as Motul which is what you'd want for significant track usage.

I do a couple HPDEs a year so I change it at least once a year and bleed the brakes a couple times a year.

 

Cool, thanks for the info guys. Is it true about DOT 4 needing to be changed more often?

Do you guys run SS lines?

 

SS lines yes.. they give you a good feel/ 'sense' that the brakes are working due to the reduction in flex in the lines.. but dont let that fool you in thinking you can stop sooner.


as for changing the fluid often? i havent seen the need to, but i've changed my fluid about once a year since i've had the car just because of work being done on my brakes. so i dunno about the validity of keeping the Dot 3/4 mix in there for long period of time.

 

http://www.stoptech.com/tech_info/wp...fluid_1a.shtml

enjoy!

 

Well that article makes me want to use a GOOD dot 3 fluid... but most of the fluids listed were higher than DOT 4 BP's .... and the lowers ones like the valvoline synpower and castrol LMA were dot3/4 it seemed like ... it said they "exceed dot 3 and dot 4" standards or something....

 

Actually...while we're learning about fluid...

Are all SS lines created equal? Because ive seen some russel lines and other brands go for a lot less than some of the higher end or "name brand" lines.... espcially considering they are part that is mostly for "feel".

 

First decide if you want to change fluid weekly, monthly or annually and that will tell you what fluid to buy.

Oem wants a long lasting fluid so they chose Dot3 however be allert to viscosity differences as you go to higher boiling points and these may change the reaction time of ABS and TCS systems.............thicker takes longer to move in system or changes in pedal pressure.............not usually material in the scheme of things but 1/50 -1/10 of a sec counts sometimes.

Why oem warns about other fluid types.

If you ever boil any brake fluid especially high temp it must be changed immediately like that day as it then reacts with moisture and turns acidic.

 

Is there any way to tell if youve boiled it besides if it came out the resevoir on to your engine bay? Or is it just the really soft pedal feel?

 

http://www.aa1car.com/library/bfluid.htm

Use google for brake fluid testers and brake fluid test strips.

Remember to test master cylinder and the bleeder at each wheel.


OR JUST CHANGE IT FREQUENTLY.

http://www.babcox.com/editorial/bf/bf40142.htm

 

Im going to pick up some of that valvoline syntech dot3/4, how much do I need to bleed the entire system?

 

I was going to change my fluid this weekend, how much does it take?

 

I bleed mine after every autocross and PDS, inbetween events i bleed them at every oil change, just a couple of pumps every time. Doing this keeps fresh fluid in the calipers at all times.

 

One of the 32oz bottles is more than enough to flush the brake system.

 

Thanks Dave.