brake fluid...DOT3 and DOT4

andrew27

Known Member
Senior Member

andrew27

Known Member
Senior Member
Oct 7, 2006
124
5
1,518
brothers of zth i hav a curious question...lets say my car(kancil) written on the cap saying 'USE ONLY DOT3', will it make any difference if i use a DOT4??i mean i didn't mix,i flushed out all the brake fluid and pour in DOT4 before bleeding the system...some told me tat it will damage the brake line o master cylinder..is it true??
 

fct

Known Member
Senior Member

fct

Known Member
Senior Member
Nov 15, 2003
211
2
3,018
kluang,jb,spore
dot 3 dot 4 also can.
i m using dot 4 in kancil.
dot 3 lower boiling point,dot 4 higher.

Bump: dot 3 dot 4 also can.
i m using dot 4 in kancil.
dot 3 lower boiling point,dot 4 higher.
 

riduanteo

Active Member
Senior Member

riduanteo

Active Member
Senior Member
Apr 12, 2006
28
0
1,501
bro just borrow ur thread btw is it trus i was told by my mechanic that the brake oil no need to change because it wont harm ur car and i already change my brake oil on the 3rd year since i bought my car and now already 3 years i never change it will harm my brake?
 

jeffayn

500 RPM
Senior Member

jeffayn

500 RPM
Senior Member
Mar 27, 2004
621
62
3,028
Klang
brake oil wont hard anything also...

the only reason we change the brake oil , is because the brake oil loves water.... whenever it get contact with water, it will hug them together and be very good friend...

and you know what, when we brake we created alot of heat and brake oil best new fren water is the heat worst enemy.

we do not use water as brake fluid because of 1 reason, because water is compact-able and it boils. so if we use water in brake line, the lining will fail under pressure because you compact it , or it will burst because the water boil in the lining and the lining fail to contain it.

so its reasonable to change the fluid completely say when you car reach 50-60k mark ...
 

zendengoh

Known Member
Senior Member

zendengoh

Known Member
Senior Member
Feb 11, 2008
155
0
1,516
KL Kepong
www.zhapalang.com.my
Conventional glycol-based brake fluid is hygroscopic, which means that it absorbs water. This is important, in order to keep condensation in the brake system from causing corrosion. However, eventually, the fluid will absorb all the moisture it can hold, reaching its point of saturation. Several things can happen at this point. Unabsorbed moisture can begin to collect in the system, causing corrosion in critical areas; the water can cause seals to swell and deteriorate, further contaminating the fluid; and the boiling point of of the fluid drops beyond recommended levels. This means that under high-heat braking conditions, such as during hard braking or repeated brake application while descending a mountain, the fluid will start boiling sooner, which will reduce braking performance. The pedal can begin to feel spongy, and as braking efficiency drops, it takes longer to stop the vehicle.
 

andrew27

Known Member
Senior Member

andrew27

Known Member
Senior Member
Thread starter
Oct 7, 2006
124
5
1,518
this is somethin i just read from a servicing book.."we can use either 1 types of brake fluid but not mixing the both(dot3 and dot4 or any other) brake fluids together"...like wad bro jeffayn said its best to change during certain service intervals to maintain our vehicle's performance at its best...but some service centers dun even care,they just take new brake fluid pour wit the old one,bleed bleed abit and done...unless u're really observant u'll c tat it's still brownish in colour and not golden transparent...
 

zendengoh

Known Member
Senior Member

zendengoh

Known Member
Senior Member
Feb 11, 2008
155
0
1,516
KL Kepong
www.zhapalang.com.my
u can mix, but what for, since dot 4 is more expensive than dot3, and once u mix will degrade the performance.
 

fct

Known Member
Senior Member

fct

Known Member
Senior Member
Nov 15, 2003
211
2
3,018
kluang,jb,spore
just try to services the brake plus flush and change the oil every year if can.
anyway not that expensive as people always take care only the engine by change engine oil every xxxxkm but the important thing (brake) that keep people's life do not put in much effort to maintain.
dot 3 dot 4 also can be use la,important is to change it regularly like ur engine oil.
when u service the brake,foreman also will visual check 4 d brake pump,master pump,brake line,caliper for jammed,oil leak or worn.
for normal car usage,dot 3 will do
for those installed high temp brake pad,better use dot4 and above.
 

K2 stanley

Known Member
Senior Member

K2 stanley

Known Member
Senior Member
Mar 24, 2009
161
9
1,518
Usually for normal daily use dot-3 is enough, but if u is a hardcore braking fans then u better use Dot-4 due to dot4 can stand higher temp. by the way do not use Dot5 if the brake cover is writing dot3.