DEFC6N1

Hi All, I plan to flush my brake system and wondering what fluid I should replace with. I plan to track my car occasionally so please keep this in mind with any recommendations.

Mordeth

Motul 600

96GS#007

Motul 600 or Ate Type 200

Keep in mind that if you plan to track the car, you need to bleed more frequently. I recommend every 90 days or before each event, whichever is longer.

Cheaping out and having the brake pedal go to the floor after a 100+ mph straight is a poor time to discover that saving $30 was a bad choice.

tw78911sc

Also, even after your bleed the entire system, take the car out and go hard on the ABS, the ABS unit has a reasonable amount of fluid that doesn't bleed out, forcing the ABS will cycle out the bad/old fluid in it.

Dano523

The C6 ABS unit has a pump that really needs to be cycled to drive the old fluid out of it, then the rest of the system be power flushed next.


So that way I do a power flush since I do have a Tech II,

Start with removing the fluid from the reserve tank, cleaning the tank, then filling it with fresh fluid.

Now using the power flusher on the tank, will power bleed the passenger rear caliper until it flows clean with the fresh fluid to begin with. At this point since I have fresh fluid all the way down to the ABS unit, will use the tech II to do a basic brake bleed, which will cycle the ABS valves and ABS pump to push the old fluid out of them, draw in new fluid.
Once that is completed, then will go back to a normal power bleed again, being passanger rear first until if flow clear again, then driver rear until if flows clear, passansger front, and then final drivers front: all the while making sure that at no time has the brake resivor become half full or less of fluid instead.


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As for brake fluid, Motul 600 a the high boiling point for a Dot 4 fluid (594), but can be spendy and over kill if not needed instead.
https://www.lelandwest.com/brake-flu...ison-chart.cfm

Hence if your going to street drive the car mostly, and then after each HPDE event if you are running street tires/not getting the brakes that hot to begin with, do a quick power bleed again after each HPDE event, may be better off with prestone dot 4, which is a hell of lot cheaper instead.
Note, will take about a quart of fluid to do a power flush correctly, so about $20 of fluid with prestone dot 4 each time, verses about $60 using Motul 600 instead.

And no, do not have anything against Motul 600 since it very good fluid with a high boiling point, but it's more than most novice drivers need, and by having a less expensive fluid that they can use to do the power flushes after each HPDE event, more likely to do the needed power bleeds after each event, so the fluid is always dry, and not dealing with water contaminated older fluids that may have a lower boiling point instead.

Hence Prestone 4 has a dry boiling point of 510, while Motul 600 that has adsorb moisture out of the air from not being change enough, may have boiling point of 401(wet) instead.

Also, don't use dot 5 or 5.1 in the vet!!!!!!
Use dot 3 or dot 4 only.

davidfarmer

https://www.walmart.com/ip/Prestone-...fl-oz/20746453

Prestone Dot 4 is great, it's cheap, and it's available locally usually. My O'Reilly has the larger bottles generally in stock.

Vette_Fan

I've been using Prestone products for a long time. How's the Valvoline Synthetic Dot 4 compared, any differences?

That's great info . Questions, since I am considering getting it done at a regular repair shop (for lack of tools/skills), they do power flush brake fluid, how to you recommend I ensure they follow the right process to replace the fluid from ABS also?

Dano523

Again, the break down boiling points on brake fluids.

https://www.lelandwest.com/brake-flu...ison-chart.cfm


As for Valvoline Synthetic Dot 4, its a Dot 3/4 high breed, and has a boiling point of 480.
So the Prestone Dot 4 is about the same price and has higher boiling point of 510 instead.

dmk0210

I always ignore the dry boil point and look at the wet boil point. The Prestone and Valvoline don't look as great with those numbers (311).

I usually use ATE typ 200 or Motul 600. Those are both rated about 400 deg.

dr_gallup

Nice link but it seems like quite a few brands just list the DOT specification minimums for their boiling points, particularly wet. Maybe that's really their true performance but since there are quite a few I suspect their legal department made them do that.

Edit:
Just noticed that the Red Line wet & dry numbers seem to be reversed. Not sure I believe the Carbone Lorraine wet number either, expect that's dry.