How much brake fluid to flush system
Joined: Jan 2004
Posts: 21,095
Likes: 47
From: Toronto, GTA north
How much brake fluid to flush system
Installing braided lines & Motul DOT 5.1 synth brake fluid soon.
I don't see any references to the amount of fluid req'd for a flush??
Need to know how much Motul to order, 1pint 2,3???
Any help appreciated.
I don't see any references to the amount of fluid req'd for a flush??
Need to know how much Motul to order, 1pint 2,3???
Any help appreciated.
Joined: Jan 2004
Posts: 21,095
Likes: 47
From: Toronto, GTA north
Originally Posted by Q45tech
Better safe than a drop short~~ 1 liter.........the higher the boiling temp the more frequently it needs changing [faster it absorbs moisture]
Exactly what I was thinking;
Didn't want to be in the middle of bleeding the last line & oops..... out of fluid.
Also, thanks for the BP info. I also found this info from another source.
In real world terms DOT 5.1 synthetic fluid "DOES" make a difference as the fluids viscosity is 820 is lower than DOT 4 or 3, this allows for easier flow throught the braking system this means, quicker response, and more precise brake pedal feel, ask any G35 owner with BREMBO's with this fluid change.
And I am not sure where you got your information from BUT the fact also is that normal DOT 5.1 has a HIGHER wet boiling point 375F and the dry boiling point is also higher 518F, Motul DOT 5.1 has a wet boiling point of 356F, and a dry boiling point of 509F. DOT 5.1 brake fluid is also INHERENTLY MORE hydroscopic, its ability to hold moisture is much better than the lower DOT fluids , not to the rate of DOT 4 or DOT 3 which has lower boiling points, hence DOT 5.1 fluids requires less maintenance. DOT 5.1 brake fluid is a better choice for many racers yet some DOT 3 performance fluids can have as high as 675F boiling point. Hope this clarifys better.
...............Dry Boiling Point....Wet Boiling Point
DOT 3 .......... 401 F ................. 284 F
DOT 4 .......... 446 F ................. 311 F
DOT 5 .......... 500 F ................. 356 F
DOT 5.1 ....... 518 F ................. 375 F
And I am not sure where you got your information from BUT the fact also is that normal DOT 5.1 has a HIGHER wet boiling point 375F and the dry boiling point is also higher 518F, Motul DOT 5.1 has a wet boiling point of 356F, and a dry boiling point of 509F. DOT 5.1 brake fluid is also INHERENTLY MORE hydroscopic, its ability to hold moisture is much better than the lower DOT fluids , not to the rate of DOT 4 or DOT 3 which has lower boiling points, hence DOT 5.1 fluids requires less maintenance. DOT 5.1 brake fluid is a better choice for many racers yet some DOT 3 performance fluids can have as high as 675F boiling point. Hope this clarifys better.
...............Dry Boiling Point....Wet Boiling Point
DOT 3 .......... 401 F ................. 284 F
DOT 4 .......... 446 F ................. 311 F
DOT 5 .......... 500 F ................. 356 F
DOT 5.1 ....... 518 F ................. 375 F
Registered User
Joined: Dec 2003
Posts: 2,514
Likes: 5
From: Marietta, Georgia
My point was the higher the dry point initially, the FASTER the drop to the wet point.
Some fluilds are so hygoscopic that they are useless after a weekend of racing.....some medium temp fluids can last years. Why oem are usually DOT 3-4 so they are average but last.........fluid boil keeps owners from destroying pads and rotors by exposing the short comings [heat sink ability of system].
Wet boiling point is roughly what happens after 30,000 miles [2 years of exposure] with DOT3-4...........not correlateable with higher dry temp fluids! Guess 1 year to wet!
http://www.stoptech.com/whitepapers/...comparison.htm
Sure you dont want to spend a few bucks more [$9 more] and get Motul Racing 600 to pickup another 90F dry [17%] improvement and 55F wet..........as long as you change it every year.
Some fluilds are so hygoscopic that they are useless after a weekend of racing.....some medium temp fluids can last years. Why oem are usually DOT 3-4 so they are average but last.........fluid boil keeps owners from destroying pads and rotors by exposing the short comings [heat sink ability of system].
Wet boiling point is roughly what happens after 30,000 miles [2 years of exposure] with DOT3-4...........not correlateable with higher dry temp fluids! Guess 1 year to wet!
http://www.stoptech.com/whitepapers/...comparison.htm
Sure you dont want to spend a few bucks more [$9 more] and get Motul Racing 600 to pickup another 90F dry [17%] improvement and 55F wet..........as long as you change it every year.
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