Outline · [ Standard ] · Linear+ Lichid frana

Thanks to Dave Zeckhausen : Lets look at what the DOT ratings mean. The table below shows the MINIMUM wet and dry boiling points for DOT 2, 3, 4, and 5 brake fluid in degrees fahrenheit. DOT 2 DOT 3 DOT 4 DOT 5 Dry Boiling point 374 401 446 500 Wet boiling point 284 311 356 The DOT 2 spec is for drum brakes and is obsolete. If you have any DOT 2 in your garage, throw it away! DOT 5 is for silicone brake fluid. Silicone brake fluid (DOT 5) should be avoided because it is not compatible with regular brake fluid, it is hard to pour without introducing bubbles and thus results in soft pedal feel, and moisture still gets into your system and will pool in low areas like your calipers and encourage rapid corrosion. STAY AWAY! That leaves DOT 3 and DOT 4 fluids. These fluids are compatible with each other and may be interchanged or mixed with no ill effects. Let's look at some popular brake fluids and their boiling points: Fluid DRY WET Castrol LMA DOT 3/4 446 311 Ford Heavy Duty DOT 3 550 290 ATE Super Blue Racing 536 392 ATE TYP 200 536 392 Motul Racing 600 585 421 Castrol SRF 590 518 Performance Friction 550 284 Castrol LMA is very good at rejecting moisture and may be kept in your brake system for a couple years. The LMA stands for "Low Moisture Activity". This is the minimum quality stuff that I would use in my Impala. It comes in plastic containers which do not have a long shelf life. Don't buy lots of this stuff at a time because moisture can make its way through the plastic containers. Ford Heavy Duty DOT 3 is VERY inexpensive and is popular among racers because of its excellent dry boiling point. It absorbs moisture quickly, but the racers don't care since they change their fluid frequently. Comes in metal cans so it may be stored. I would not use this in my Impala for the street. ATE Super Blue Racing and ATE TYP 200 are the same brake fluid in two different colors (blue and amber, respectively). BMW recommends this brake fluid for their street cars because it, like Castrol LMA, absorbs moisture very slowly. The advantage over LMA is that ATE has a much better wet boiling point. You can put this stuff in your car and forget about it for a long time. An excellent choice for a weekend track car which also sees regular street duty. Comes in metal cans. This is what I use in all my street cars. Motul Racing 600 is a very exotic and expensive synthetic fluid with high wet and dry boiling points. I use this exclusively in my race cars. Too expensive for the street and requires frequent changing due to its hygroscopic nature. Sold in plastic bottles. It is not suitable for the street because it absorbs moisture quickly. Castrol SRF is a hyper-exotic and hyper-expensive brake fluid that is generally used by wealthy Porsche owners at track events. I've seen prices of $78 per liter for this stuff. Sold in metal cans. I can't afford this stuff! Performance Friction High Performance DOT 3 has a good dry boiling point but a crummy wet boiling point. It comes in metal cans which is good for shelf life and sells for $7.87 per 16 ounce container. If you are even considering this fluid, I would go with the cheaper Ford Heavy Duty DOT 3. In either case, change this fluid frequently due to the poor wet boiling point. -------------------------------------------------------------------------------- Thanks to Leigh Smith for the following information on the impact of moisture content in brake fluid : The amount of moisture in brake fluid definitely affects its performance. The big problem is it is absorbs moisture quickly. Over a relatively short period of time brake fluid will absorb moisture from the air. SAE field tests have shown that the average one year old car has 2% moisture in the fluid. A random test of vehicles in the U.S. showed an average water content of 2.6% for vehicles with an average age of 8 years. And 25% of these vehicles had water content greater than 4%. As water content in brake fluid increases over time, the boiling point decreases. Fluid with a reduced boiling point (or high water content) can create vapor by boiling in the caliper, or wheel cylinder. The result is sudden brake failure. And water in the brake fluid can contribute to corrosion of parts such as steel pistons and ABS modulators. The end result is even though DOT 3 fluid is "rated" at greater than 401oF, in the typical 3 to 4 year old car with 3 to 4% moisture content, it could boil under 300oF. And if it has got more than 4% moisture, you may as well be running straight water! Moral: Flush your brake fluid every year or so. But only if you would like it to work well scarcely an inch away from those toasty 500oF rotors on your SHO during a couple of hard stops! Or would you rather have a squishy pedal? Technical data courtesy of Leica Refractometers. www.leica-ead.com. Sursa: http://www.shotimes.com/SHO3brakefluid.html

Thanks to Dave Zeckhausen :
Lets look at what the DOT ratings mean. The table below shows the MINIMUM wet and dry boiling points for DOT 2, 3, 4, and 5 brake fluid in degrees fahrenheit.
DOT 2 DOT 3 DOT 4 DOT 5
Dry Boiling point 374 401 446 500
Wet boiling point 284 311 356


The DOT 2 spec is for drum brakes and is obsolete. If you have any DOT 2 in your garage, throw it away! DOT 5 is for silicone brake fluid. Silicone brake fluid (DOT 5) should be avoided because it is not compatible with regular brake fluid, it is hard to pour without introducing bubbles and thus results in soft pedal feel, and moisture still gets into your system and will pool in low areas like your calipers and encourage rapid corrosion. STAY AWAY!

That leaves DOT 3 and DOT 4 fluids. These fluids are compatible with each other and may be interchanged or mixed with no ill effects.

Let's look at some popular brake fluids and their boiling points:

Fluid DRY WET
Castrol LMA DOT 3/4 446 311
Ford Heavy Duty DOT 3 550 290
ATE Super Blue Racing 536 392
ATE TYP 200 536 392
Motul Racing 600 585 421
Castrol SRF 590 518
Performance Friction 550 284


Castrol LMA is very good at rejecting moisture and may be kept in your brake system for a couple years. The LMA stands for "Low Moisture Activity". This is the minimum quality stuff that I would use in my Impala. It comes in plastic containers which do not have a long shelf life. Don't buy lots of this stuff at a time because moisture can make its way through the plastic containers.

Ford Heavy Duty DOT 3 is VERY inexpensive and is popular among racers because of its excellent dry boiling point. It absorbs moisture quickly, but the racers don't care since they change their fluid frequently. Comes in metal cans so it may be stored. I would not use this in my Impala for the street.

ATE Super Blue Racing and ATE TYP 200 are the same brake fluid in two different colors (blue and amber, respectively). BMW recommends this brake fluid for their street cars because it, like Castrol LMA, absorbs moisture very slowly. The advantage over LMA is that ATE has a much better wet boiling point. You can put this stuff in your car and forget about it for a long time. An excellent choice for a weekend track car which also sees regular street duty. Comes in metal cans. This is what I use in all my street cars.

Motul Racing 600 is a very exotic and expensive synthetic fluid with high wet and dry boiling points. I use this exclusively in my race cars. Too expensive for the street and requires frequent changing due to its hygroscopic nature. Sold in plastic bottles. It is not suitable for the street because it absorbs moisture quickly.

Castrol SRF is a hyper-exotic and hyper-expensive brake fluid that is generally used by wealthy Porsche owners at track events. I've seen prices of $78 per liter for this stuff. Sold in metal cans. I can't afford this stuff!

Performance Friction High Performance DOT 3 has a good dry boiling point but a crummy wet boiling point. It comes in metal cans which is good for shelf life and sells for $7.87 per 16 ounce container. If you are even considering this fluid, I would go with the cheaper Ford Heavy Duty DOT 3. In either case, change this fluid frequently due to the poor wet boiling point.



--------------------------------------------------------------------------------

Thanks to Leigh Smith for the following information on the impact of moisture content in brake fluid :

The amount of moisture in brake fluid definitely affects its performance. The big problem is it is absorbs moisture quickly. Over a relatively short period of time brake fluid will absorb moisture from the air. SAE field tests have shown that the average one year old car has 2% moisture in the fluid. A random test of vehicles in the U.S. showed an average water content of 2.6% for vehicles with an average age of 8 years. And 25% of these vehicles had water content greater than 4%.

As water content in brake fluid increases over time, the boiling point decreases. Fluid with a reduced boiling point (or high water content) can create vapor by boiling in the caliper, or wheel cylinder. The result is sudden brake failure. And water in the brake fluid can contribute to corrosion of parts such as steel pistons and ABS modulators.

The end result is even though DOT 3 fluid is "rated" at greater than 401oF, in the typical 3 to 4 year old car with 3 to 4% moisture content, it could boil under 300oF. And if it has got more than 4% moisture, you may as well be running straight water!

Moral: Flush your brake fluid every year or so. But only if you would like it to work well scarcely an inch away from those toasty 500oF rotors on your SHO during a couple of hard stops! Or would you rather have a squishy pedal?

Technical data courtesy of Leica Refractometers. www.leica-ead.com.

Sursa: http://www.shotimes.com/SHO3brakefluid.html

Ce e chestia aia de sus ca nu inteleg mai nimic. Nici n-am timp acum sa studiez mai bine. Chestia e ca am o intrebare si am dat search sa vad daca s-a mai postat si n-am gasit nimic, decat topicul asta care are legatura cu problema mea. Problema e: la Dacia mea a inceput sa se aprinda becul rosu BRAKE (ala dreptunghiular). Tata zice ca tre completat lichidul de frana si sa cumpar o sticluta de 200-250 ml. Eu am vrut sa verific ca chiar asta e cauza. Stie cineva? Mentionez ca, din cate stiu, are servofrana. Si inca franeaza binisor, dar... Ce lichid ar fi mai bun si compatibil cu ce am deja in Dacie (habar n-am ce am dar ce s-o pune de obicei) ?

This post has been edited by Cornel001: 24 Jun 2005, 01:18

pune dot 3 !ai grija daca se aprinde indicatorul poate ai lichid doar pe conducete!atentie!!!!

Mersi de raspuns! Am fost si am luat dot3. Si raspunsul tau m-a lamurit mai bine ce vroia sa zica articolul de mai sus citat de klaus

M-am tot întrebat, oare ce se depreciază la lichidul de frână de tot susţin producatorii de autoturisme ca trebuie schimbat lichidul de frână. Acum am înţeles şi problema se pune în special la şoferii cu un stil de conducere mai sportiv.
Un post interesant...

Lichidul de frana e hidrofil (cred ca asta e termenul..), adica "atrage" apa, si asfel ijn timp "inglobeaza" apa, ceea ce face ca sa ii scada temperatura de fierbere, scad astfel performantele franarii, etc. In plus tevile circuitului de franare se corodeaza de la apa.
S-ar putea sa conteze si stilul de condus; am vazut mai demult un tabel cu producatorii de autoturisme si perioada sau nr de km cand trebuie schimbat lichidul de frana. Majoritatea erau cu 1 sau 2 ani, si ca nr km 20k-60k. Singura exceptie era Ferrari cu 6 luni sau 5mii km !

Ca o intrebare de dumb...

Pe la noi in romanica se gaseste pe rafturile magazinelor, un lichid de frana TIP N... Asta de care e? unde se regaseste intre cele enumerate de klaus...dot 3, 4...???
E in sticlute de plastic de 250 si 500 ml, de culoare gri, si o eticheta alb cu visiniu...

Am vazut si eu....cred ca este tip DOT 3 (e recomandat pt Dacii), si la Dacia pana acum cativa ani se folosea DOT 3.

tip N este dor 4 sau dot 3!adica pt ale noastre!

SYL, lichidul de frana nu e "hidrofil".E higroscopic.Adica absoarbe apa.

Klaus a uitat sa precizeze ca temperaturile de acolo sunt in grade Farenheit (conversia: http://www.scorpiosite69.freeserve.co.uk/temperature.htm ).

Un lichid de frana interesant, cu pret de 3,9 euro/250 ml este si Pentosin (Dot4) - ptr Dacie e super ok. Are aceleasi performante ca si ATE Super Blue si e mai usor de gasit.

am luat azi 2+2 , 120.000 cica e bun,cred ca e bun, astea romanesti(bidon negru,eticheta visinie i bidon albastru,eticheta galbena) mananca garniturile. sant patit.

As vrea sa mai punctez niste lucrururi:
Lichidele de frana sunt clasificate de Department of Transportation (DOT) cu un numar DOT. Aceste numere au la baza atat componenta chimica cat si performantele pe care trebuie sa le aiba lichidul de frana. Acest numar DOT mentioneaza caracteristicile minime pe care trebuie sa le aiba lichidul (asta inseamna ca un lichid DOT 3 de la o firma sa corespunda binemersi la caracteristicile DOT 4)
Din punct de vedere chimic, lichidele de frana se impart in doua categorii:

1. DOT 3, 4 si 5.1 sunt bazate pe Glycol. Rezistenta la caldura a lichidelor pe baza de glycol scade dramatic odata cu absorbtia de apa, chiar si in cantitate f. mica.
Lichidele pe baza de glycol sunt higroscopice. Ele atrag apa si din surse f. butin vizibile (ca de ex., odata ce capacul a fost desigilat, lichidul incepe sa absoarba apa. De aceea nu este indicat utilizarea unui lichid de frana aflat intr-un recipient la care nu se stie de cand este deschis; sau abssoarbe prin garniturile sistemului de franare, pe care daca nu se depune apa de la ploaie, se condenseaza din atmosfera)
Procentul de apa din lichidul de frana creste cu ca. 1-2% in fiecare an de utilizare
Apa in lichidul de frana scade punctul de fierbere a lichidului si mareste capacitatea de compresie a lichidului (lucru de evitat).
Acesta este motivul principal pentru are la cca. 2 ani lichidul de frana trebuie schimbat.

2. DOT 5 sunt bazate pe silicon.
Lichidele bazate pe silicon nu sunt higroscopice si nu absorb apa din aer, insa apa tot poate ajunge in instalatia de franare. Aceste molecule de apa conduc la scadere punctului de fierbere a lichidului si la coroziune (apa nu se amesteca cu lichidul si circula sub forma de "bule" prin circuit)

I. Lichide bazate pe glycol (dot 3, 4, 5.1)
Acestea sunt lichidele folosite in mod normal in sistemele de franare. culoarea lichidului atunci cand este "curat" este o culoare usor galbuie sau transparenta. Daca lichidul capata o culoare maronie sau negra, ar trebui schimbat.
DOT 3 - are punct de fierbere la cca. 205 C,
DOT 4 - punct de fierbere la cca. 230 C. Lichidele DOT 4 sunt mai higroscopice decat cele DOT 3, si de aceea pot ajuge destul de repede sa aiba aceleasi caracteristici cu cele DOT 3
DOT 5.1 - punct de fierbere la cc. 260 C. Este conceput pentru sistemele de franare cu ABS care au modulatoare (valve de control) si care au cerinte suplimentare fata de cele DOT 3, 4.
Mai este cunoscut si ca DOT 4 plus.
Niciodata sa nu se foloseasca lichide bazate pe silicon (DOT 5) in locul celor bazate pe glycol (DOT 3, 4 sau 5.1)

II. Lichidele bazate pe silicon (DOT 5)
Lichidele bazate pe silicon nu absorb apa, deci isi pastreaza mai mult caracteristicile de fierbere decat cele bazate pe glycol.
Utilizarea lichidelor pe silicon nu inseamna ca nu trebuie schimbate regulat. Astfel, desi nu absoarbe apa, totusi aceasta isi gaseste loc de intrare in sistem, scazand astfel punctul de fierbere, si formand picaturi si bule care corodeaza elementele de metal ale sistemului de
Acestea se folosesc cu precadere la masinile de expozitie (nu ataca si strica vopseaua), karturi, motociclete, vehicule militare si la bicicletele cu frane hidraulice.

Lichide si cantitati:

Supernova lichid SAE J 1703 DOT 4, 0.650l
Solenza lichid SAE J 1703 DOT 4, 0,450l
Logan lichid SAE J 1703 şi DOT 4, 0,5l

as vrea sa stiu si eu cam ce lichid de frana (marca) este bun pt daciile berline. Daca a cumparat cineva un lichid de frana si a fost multumit de el. Eu am folosit dastea romanesti...si pot sa spun ca sunt jalnice.Am toata instalatia de franare noua pe masina.Tot aud ca depinde si ce fel de lichid de frana folosesc, de ex: unu romanesc costa 50.000 iar la aceeasi cantitate unul strain costa 200.000. As vrea sa stiu cam ce lichide de frana folositi si daca se poate si niste preturi.

pai dot 3.nu stiu pretul.de firma nu stiu ce sa-ti recomand.total ar fi bun sau unele nemtesti

totusi am o nelamurire!!! de ce lichid de frane DOT5 nu este recomadat la ..ex. Dacia Supernova ????

astept un raspuns cu un real interes, pt. ca trebie sa-l schimb
Si ce producator este mai bun pt. SRN?? si ce categorie??

1. Pentru ca lichidele de franare pe baza de glicol (DOT 3, 4, 5.1) nu sunt compatibile cu cele pe baza de silicon (DOT 5) (lumea zice ca formeaza la amestecarea lor niste "gume" care nu fac bine circuitului sub presiune, si devine extrem depericuloasa franarea cu acei compusi in circuit). Eu din cate stiu, cele doua nu se amesteca intre ele si astfel ramane pe circuit lichid glicolic, care atrage umezeala, si care va creste astfel inevitabil compresibilitatea lichidului si va scadea punctul de ferbere.
2. Pentru ca lichidele bazate pe silicon nu sunt compatibile cu piesele de "cauciuc" pe baza de siliconi
3. Lichidele de franare pe baza de silicon se "lipesc" de rezidurile din circuitul de franre (murdarie, resturi de la garnituri rezultate in urma uzurii) si pot crea niste "gelatine" care pot infunda circuitul.
4. Lichidele DOT 5 sunt scumpe (si la noi nu prea se gasesc)
5. Lichidele DOT 5 sunt mai expuse la aer mai mult in instalatie (nu se poate face aerisirea complet).

multumesc mult pt. raspuns
m-am lamurit

eu recomand castrol!e cam scump da merita!

am luat azi 2+2 ,  120.000 cica e bun,cred ca e bun, astea romanesti(bidon negru,eticheta visinie i bidon albastru,eticheta galbena) mananca garniturile. sant patit.

Nu e dot4? Am auzit de la un mecanic ca nu e bun dot 4 pt dacie. .Am vrut sa cumpar si eu azi dar m-am razgandit si am luat tot unul romanesc...DOT 3

This post has been edited by Radduu: 3 Feb 2006, 18:58

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Radule .... nu stiu ce lichid de frana e ala .... dar nu imi inspira incredere deloc ...

scrie pe el autentificat rar....il folosesc de putin timp si mi se pare normal. Oricum, am fost acum la shell si am gasit lichid de frana 2+2 DOT3 si mi-am cumparat dasta. Sper sa fie bun de ceva..

This post has been edited by Radduu: 3 Feb 2006, 21:01

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vedeti ca la daciile mai noi sau poate si inainte se poate folosi linistit DOT4. In cartea cu instructiunile de folosire de la dacia mea din 97 specifica ca se poate folosi si DOT3 si DOT4. LA vara o sa schimb si eu lichidulde frana

Logic ca se poate folosi si dot 3 si dot 4, se pot amesteca fara nici un fel de problema.

Pentru dacii se recomanda DOT 3. Cel mai bun (calitate/pret) este cel facut de Desan. E un producator de la noi, are fabrica in bucuresti.
nu ataca nimic, daca de asta mi-a fost frica vreo secunda...
costa destul de putin si e la fel de bun ca 2+2 sau castrol. care costa de 3 ori mai mult.