what brake fluid is needed ?
- Thread starter woolley
- Start date
Braveheart
New Member
You can use any .... your call. Just do not mix 5.0 with 3, 4 or 5.1.
DOT 3 and DOT 4 are functionally very similar. 4 has a higher boiling
point, but motorcycle brake systems don't generate the kind of pressure and
temperatures that need it on the street, in general, although it certainly
won't hurt your system to put it in.
DOT 5 is very different--it's silicone based, doesn't absorb water, isn't
corrosive, is bad for some seals, is hard to bleed, and is not miscible
with 3 or 4. Stay away from it--it needs a system designed for it. And it
comes as stock item in Harley's, so it must be terrible. :->
DOT 5.1 is compatible with DOT 3 & DOT 4 (If I ever get hold of the
bonehead who named DOT 5.1...)
Here's more detail than you really want:
DOT3 is an aliphatic polyether.
DOT4 is borate ester based.
DOT5 is polydimethylsiloxane (silicone based).
DOT5.1 is borate ester based, thus its compatibility with DOT3 and
DOT4.
DOT 3 and DOT 4 are functionally very similar. 4 has a higher boiling
point, but motorcycle brake systems don't generate the kind of pressure and
temperatures that need it on the street, in general, although it certainly
won't hurt your system to put it in.
DOT 5 is very different--it's silicone based, doesn't absorb water, isn't
corrosive, is bad for some seals, is hard to bleed, and is not miscible
with 3 or 4. Stay away from it--it needs a system designed for it. And it
comes as stock item in Harley's, so it must be terrible. :->
DOT 5.1 is compatible with DOT 3 & DOT 4 (If I ever get hold of the
bonehead who named DOT 5.1...)
Here's more detail than you really want:
DOT3 is an aliphatic polyether.
DOT4 is borate ester based.
DOT5 is polydimethylsiloxane (silicone based).
DOT5.1 is borate ester based, thus its compatibility with DOT3 and
DOT4.
skiddusmarkus
Active Member
Just put 5.1 in and don't worry about those long words above.
darkyGTI-R
New Member
I have some Motul dot 5 ready to go in mine I haven't changed it since i've had the car nearly 2 and half years now