ωΰμϊ ϊν,
ψλα αο 15 ωπδ , 260 ΰμσ χξ' , ξςεμν μΰ δεημσ πεζμ αμξιν,
ξδ δδωμλεϊ ? δΰν ΰπι ΰξεψ μδψβιω γςιλδ/αςιδ ααμιξδ ?
ϊεγδ
ψςπο
ξωϊσ ΰεϊλν ... λγΰι ωϊγςε:
πεζμ αμξιν\ωξο αψχρ ρετη ξιν ςν δζξο, μλο ιω μδημιτε τςν αωπϊιιν.
αθιτεμ δωεθσ ωμ ΰηϊ ξξλεπιεϊ δξωτηδ αξερκ ψωϊ διαεΰο αιχωϊι ωιημιτε.
ρξϊι μα ωξεζβιν πεζμ ηγω ξαχαεχ ρβεψ ΰαμ DOT3 ωμΰ ξϊΰιν μABS - ςμ ΰσ ωαξλρδ ωμ ξιλμ πεζμ δαμξιν λϊεαδ ΰζδψδ ωιω μριν ΰκ εψχ DOT4.
μΰηψ ωδςψϊι - μχη μδν ζξο μδωϊλπς, αθιςεο ωδν ξεζβιν μλεμν DOT3 εζδ αργψ -
ηιθϊε εξφΰε αξηρο αχαεχεο DOT4 - ψΰε ϊξεπδ
ΰζ ρξϊι μα μϊΰψικ διιφεψ ... τψδ διρθεψιδ ... αξερβιν ωμ πεζμ χιψεψ, δψι δεΰ ρετβ ξιν αξιλμ
τμρθιχ ξ2009 ςγ 2012 ΰζ ξδ ςωιπε αδημτδ ?
αιχωϊι ΰηψ, δμλε χπε εδαιΰε ΰϊ ζδ:
πψΰδ αργψ ... DOT4 ... ιιφεψ ωαες 50 ωμ 2011 (δημτϊ δπεζμ αεφς αξψυ 2012).
μΰ δωϊξωϊι αςαψ α-ATE εμλο πλπρϊι μΰϊψ ωμδν μδλιψ ΰϊ δηαψδ εδξεφψιν.
ηιτρϊι ΰϊ ΰϊ δΰψιζδ "ωμι" αιο ξεφψι πεζμι δαμξιν ωμ δηαψδ ... ΰιο ... μΰ ξετιςδ.
ξλιεεο ωαγψκ λμμ ζδ μΰ ξιχψι ΰε ωληε μριν ΰεϊε αΰϊψ ...
αιψεψ χφψ ξβμδ ϊετςδ-πεδβ ωμ ιαεΰπι ωξπιν\πεζμιν μψλα.
διαεΰπιν πεδβιν μχπεϊ ΰϊ δηεξψ αΰψιζεϊ βγεμεϊ, μιιφψ αΰψυ ΰψιζεϊ χθπεϊ εμαφς ξιμει
ωμδο αΰψυ. ΰν ςεωιν ΰϊ ζδ πλεο ζδ αργψ ... ΰαμ ϊιιγςε ΰϊ δφψλο εϊψωξε αΰψιζδ
ωδξιμει δεΰ αΰψυ εϊψωξε αΰψιζδ δχθπδ ΰϊ ϊΰψικ διιφεψ ωμ δηεξψ δξχεψι (ωδιδ αΰψιζδ
δβγεμδ !) - ζδ ξδ ωχεας μθψιεϊ δηεξψ.
λο ξδ ωψωεν λϊΰψικ ιιφεψ ωαες 50 ωμ 2011 ζδ ϊΰψικ δξιμει αΰψυ. μΰηψ αιψεψ, δϊαψψ ωδηεξψ ιεφψ
αηε"μ λξςϊ ωπδ μτπι !
χπιϊι\δρλξϊι μδϊχιο λι πψΰδ μι θψι - ρδλ"μ 3 ηεγωιν - λωαςφν δηεξψ ωιεφψ ξμτπι ωπδ+.
ΰν διϊι ιεγς μΰ διιϊι ρν.
μριλεν δχτιγε ςμ δϊχο δπλεο.
ριξε μα μϊΰψικ διιφεψ δΰξιϊι. ΰψιζεϊ τμρθιχ ρετηεϊ ξιν ςν δζξο
εςγισ ΰψιζϊ ξϊλϊ - ρετηεϊ τηεϊ (μτι ξδ ωδαπϊι, ζδ αΰ ιωψ ξδιιφψο ςν δϊΰψικ ιιφεψ δΰξιϊι).
ΰν δΰψιζδ μΰ ξετιςδ αΰϊψ διιφψο ελϊεα αςαψιϊ, ραιψ ωδϊΰψικ ζδ ϊΰψικ ξιμει αΰψυ εμΰ ιιφεψ.
ωΰμϊ ϊν,
ψλα αο 15 ωπδ , 260 ΰμσ χξ' , ξςεμν μΰ δεημσ πεζμ αμξιν,
ξδ δδωμλεϊ ? δΰν ΰπι ΰξεψ μδψβιω γςιλδ/αςιδ ααμιξδ ?
ϊεγδ
ψςπο
διδ τδ ωψωεψ αςαψ, ΰπι μΰ ξεφΰ ΰεϊε.. ΰαμ αψβς ωπεζμ δαμξιν ρετη ξιιν, δεΰ δετκ μηεξφι εδεΰ ξΰλμ ΰϊ δβεξιεϊ.
ΰπι μΰ ξξω αθεη ΰαμ δΰν πιϊο μωιν DOT4 αξχεν DOT3 ? δδτκ ΰπι ιεγς ωμΰ.
ψςπο,
ξφα λξε ωϊΰψϊ ιλεμ μδιεϊ ξρελο. ϊμει λξδ ψθιαεϊ πλπρδ μξςψλϊ.
ΰϊδ ςμεμ μδψβιω μηιφδ ρτεβιϊ εαξχψδ ηξεψ μςαγ ΰϊ χεωψ δςφιψδ.
ΰν πεζμ δαμξιν ρτη μηεϊ\ξιν ςν δωπιν πχεγϊ δψϊιηδ ωμε ϊψγ,
αζξο ςφιψδ δεΰ ιϊηξν ιδτεκ μβζ. βζ δεΰ μηιυ ==> ιδιδ ρτεβι.
ιωι,
δ-DOT ξβγιψ ΰϊ θξτψθεψδ δψϊιηδ εδδψλα δλιξι (ωιξπς τβιςδ αβεξιεϊ).
θξτ. ψϊιηδ α-DOT4 βαεδδ ξ-DOT3, μβαι δψλα δλιξι ΰπι ηεωα ωβν ΰτωψι - λγΰι μαγεχ αϊχο.
χψΰε λΰο:
The Department of Transportation (DOT) classifies brake fluids to defined specifications.
These specifications relate to their boiling points and chemical composition, both of which are important.
All currently available brake fluids are covered by one of the following specifications; DOT3, DOT4, DOT5 and DOT5.1.
The laws of thermo-dynamics dictate that the energy from motion is turned into heat through friction.
A braking system only works efficiently if the fluid remains incompressible.
If the brake fluid boils, it turns to gas, which is compressible and the braking system becomes spongy or in extreme cases fails completely.
A brake system is not perfectly sealed and moisture can get into the system and be absorbed by the fluid.
The effect is to reduce the boiling point of the fluid, which reduces the efficiency of the braking system, as described above.
The DOT specifies two reference tests for brake fluids.
* Dry boiling point - the boiling point of fresh fluid
* Wet boiling point the boiling point once the fluid has absorbed moisture (representing brake fluid after time spent in a real situation
).
There are two main types of brake fluids:
* DOT 3, DOT 4, Super DOT4* and DOT 5.1 which are based on poly glycol compounds.
* DOT 5, which are based on Silicone.
Note the two types of fluid are not compatible and must not be mixed in a braking system.
SILICONE BRAKE FLUID (DOT 5
)
Silicone based DOT 5 was originally introduced to give higher temperature performance over glycol DOT 4.
Silicone fluid also has other advantages, it does not damage paintwork and it does not absorb water.
However, silicone fluid is a poor lubricant and does not lubricate ABS pumps as well as PAG fluids.
It is also more compressible than PAG fluids, which can result in a sluggish or spongy pedal. It therefore requires special design considerations in braking systems.
Further, because it does not absorb water, any water remains as globules, which can pool in low spots in the system and cause corrosion.
This water can vaporise when heated under heavy braking giving a disastrous effect on braking efficiency.
DOT5 fluids are not recommended for motor sport applications.
POLY GLYCOL BRAKE FLUIDS (DOT 3, 4 AND 5.1)
Glycol based DOT 4 fluid is the current mainstream brake fluid, and you will see that the specification is considerably better than DOT 3 which it replaces.
DOT 5.1 has higher specification still and is for fast road and occasional track day use.
It has a similar spec to DOT4 for the boiling point (>260) but is a lot lower viscosity @-40C typically 900 centistokes (compared to 1500 - 1800 centistokes for DOT 4 and super DOT 4).
Listed in the table below, are the minimum dry/wet boiling point specifications for each DOT level.
BOILING POINT:
DOT 3 - 205°C (dry) / 140°C (we
t)
DOT 4 - 230°C (dry) / 155°C (wet
)
DOT 5 (silicone) - 260°C (dry) / 185°C (wet
)
DOT 5.1 (PAG) - 260°C (dry) / 185°C (wet
)
Super Dot4 * - 300°C (dry) / 195°C (wet
)
(racing brake fluid)
* Super DOT4: The main difference between DOT 4 and Super DOT 4 is the dry boiling point. Normal Dot4 is >260C whilst Super DOT 4 is more like >310C
With thanks to Martyn Mann - Technical Director Millers Oils.
ωξψε ςμ χωψ