DOT 5.1 + DOT 4

[Philzer]

Je change mon setup complet de brake sur ma 2.5 RS.. je passe aux 4 pots / 2 pots avec lignes SS. Je veux faire le flush de ma dot 4 pour mettre de la 5.1. Je sais que la dot 5 est très dangereuse si elle rencontre de la 3 ou 4... mais est ce que je peux flusher avec de la 5.1 sans danger de la meme façon que j'ai flushé ma dot 3 pour de la 4 soit en remplissant au fur et à mesure ? juste m'assurer au cas où merci

[Kolia]

dot 3
dot 4
dot 5.1

c'est tout bon pour ta voiture.

melange pas les grades ni les marques.

[Philzer]

excellent ! merci de l'info

[-Johnny-]

meh.. dot 4..dot 5.1... FYI:


ATE super blue DOT4 has a higher dry/wet boiling point than gulf racing 5.1. (581F:556F)

..gulf rf800 (dot4) boils at +300 celcius

dot5.1 absorbs water quicker than glycol based dot4.




I just semi flushed (relatively new fluid ~less than 1 year old)
gulf racing 5.1.

..I did 6-7 decelerations back-to-back from 100kph to 30 kph sunday night,

..my pedal is mushy


(ps: I had bled my brakes on thursday)


Do what you want (..cause I usually dont know what Im talking about lol) depending on the price Im going to change out my fluid for RF800,
Swapshop is a Gulf/Motul distributor, if you wish ask Max about other brands.. he can usually get them.

[Kolia]

When you bled, did you push back and flushed all the caliper pistons ?

That is the most important (and most neglected) part of brake bleeding.

[-Johnny-]

When you bled, did you push back and flushed all the caliper pistons ?

That is the most important (and most neglected) part of brake bleeding.

no!

..how do you do that..?

I have FHI4/2 piston calipers.

when I bled I had someone applying brake [smoothly&steadily],
before pedal ended its compression: I was warned,
I tightened bleeder,
released brake,
repeat compression,
bleed.

used corners service manual states

did each corner 3-4 times, no miniscule bubbles, no dirt when done.

[Kolia]

you want to open the bleed valves and push back the piston on that side to get the volume of old crapiest fluid out.

otherwise, that fluid will just swirl around the piston cavity while you pump.

[-Johnny-]

...so no compressing line [through depressing brake pedal]

compress pistons manually at caliper and bleed..?

(wont I send air up + out of caliper (toward MC) without compression before caliper?)

[Kolia]

with your rubber tube on the valve, run it in a loop to trap fluid. That keep the system sealed.

push back the pistons after opening the valve. The junk will go out the bleed valve and not toward the MC. You can buy a tool for it. It's called a Pad Spreader.

[Blackcot Racing Team]

use some c shape vise grip

and use the old pad to push on it !