Dot 4 or "Dot 3 & 4 Synthetic"

[tdisme]

I have an '04 V11 Sport and an '07 Breva that both need fluid changes. I bought a jug of Valvoline Synthetic Dot 3&4. Should I instead look around for Dot 4 (I can do that, but it means a bit of driving) or am I wasting my time and should just use what I bought?

[GuzziMoto]

I have an '04 V11 Sport and an '07 Breva that both need fluid changes. I bought a jug of Valvoline Synthetic Dot 3&4. Should I instead look around for Dot 4 (I can do that, but it means a bit of driving) or am I wasting my time and should just use what I bought?

 

tomdisme@gmail.com

There is no reason to use a DOT 4 over a DOT 3&4 that I am aware of. DOT 3&4 meets the same specs as DOT 4.

The Valvoline fluid is not as good as it used to be. The boiling points wet and dry are down a fair bit. But I have used the new version without issues. I seem to recall the older stuff came in a silver plastic bottle. For a road bike I doubt you would have issues with the lower boiling point. If you do then likely something is wrong or your a nutter.

Aside from the boiling point change it is decent stuff in my experience. Meaning I have not had any troubles as a result of running it.

[raz]

You've got DOT 4, just use it!

 

http://www.valvoline...-brake-fluid/28

 

(mid-air collision edit: GuzziMoto's answer is probably more specific but if you don't race it on track I doubt you'll need any better)

[gstallons]

I would say not to use what you have purchased.Use DOT 4 fluid only. Completely flush the stock fluid when changing and continue to use the same fluid every time.

Also, never mix silicone brake fluid with any other type(s) of brake fluid....

[drewscura]

It's extremely lengthy, but this is extremely if not overly informative about brake fluid. At least skim threw it.

 

http://www.stoptech.com/tech_info/wp_brakefluid_1a.shtml

[tdisme]

It's extremely lengthy, but this is extremely if not overly informative about brake fluid. At least skim threw it.

 

http://www.stoptech.com/tech_info/wp_brakefluid_1a.shtml

 

Great article. I suppose that silicone is "synthetic"?

[tdisme]

I would say not to use what you have purchased.Use DOT 4 fluid only. Completely flush the stock fluid when changing and continue to use the same fluid every time.

Also, never mix silicone brake fluid with any other type(s) of brake fluid....

I remembered not to mix when you mentioned it. Some say use the Valvoline, some say dont. I think I'll take it back and pick up some dot 4 at the dealership.

[raz]

I must be daft. In what way would the mentioned fluid not be DOT 4? After all, it is specified as a DOT 4 fluid. How would buing just any other DOT 4 fluid be better? And where would you find a silicone based DOT 4 fluid?

[Dan M]

Just use it. It is Dot 4 spec. Dot 4 just has a higher boil point. Valvoline is likely moving to one product to service vehicles that require either. It will mix without issue. You will not boil it.

Do not use silicone fluid (Dot 5) It will not mix with what is in your system and will jell if some Dot3 or 4 is left in the system.

 

Dry boiling point -------- Wet boiling point

DOT 3 205 °C (401 °F) - 140 °C (284 °F)

DOT 4 230 °C (446 °F) - 155 °C (311 °F)

DOT 5 260 °C (500 °F) - 180 °C (356 °F)

DOT 5.1 270 °C(518 °F) - 190 °C (374 °F)

[GuzziMoto]

I would say not to use what you have purchased.Use DOT 4 fluid only. Completely flush the stock fluid when changing and continue to use the same fluid every time.

Also, never mix silicone brake fluid with any other type(s) of brake fluid....

The fluid he bought (Valvoline) is DOT 4. It meets the DOT 4 specs as well as the lower DOT 3 specs. It is suitable for use whenever DOT 3 OR DOT 4 is required. I have used the mentioned fluid in my Guzzi's without issue.

As someone mentioned, Valvoline labels it 3 & 4 so that people with either requirement will understand that this fluid is suitable. The only real difference is the higher boiling point. It is made for use in either system.

[tdisme]

I have an '04 V11 Sport and an '07 Breva that both need fluid changes. I bought a jug of Valvoline Synthetic Dot 3&4. Should I instead look around for Dot 4 (I can do that, but it means a bit of driving) or am I wasting my time and should just use what I bought?

Plenty of answers. Thanks for your input. Dont need any more answers. I gots de dots now.

[gavo]

Just use it. It is Dot 4 spec. Dot 4 just has a higher boil point. Valvoline is likely moving to one product to service vehicles that require either. It will mix without issue. You will not boil it.

Do not use silicone fluid (Dot 5) It will not mix with what is in your system and will jell if some Dot3 or 4 is left in the system.

 

Dry boiling point -------- Wet boiling point

DOT 3 205 °C (401 °F) - 140 °C (284 °F)

DOT 4 230 °C (446 °F) - 155 °C (311 °F)

DOT 5 260 °C (500 °F) - 180 °C (356 °F)

DOT 5.1 270 °C(518 °F) - 190 °C (374 °F)

 

I've gotta ask , Dry and wet boiling points? I,ve been in the mechanical field since I was a teen and never heard of it , Please explain

[luhbo]

Breakfluid is hygroscopic. So the dry boiling point applies as long as the fluid is freshly filled up from a sealed container only.

When the B/F will have become wet depends on several things. The climate you're located in, how well sealed your brake system is and so on. I think changing the fluid every two years or so is a proper interval to keep you on the safe side. But remember - the B/F is hygroscopic also in the can you bought it in. The water saturation level can be determined by a good shop, by the way.

 

Hubert

[gstallons]

There are litmus strips available to test the moisture level in brake fluids.

[GuzziMoto]

As mentioned, but to elaborate, the dry boiling point accurately reflects the boiling point of the fluid. But being hygroscopic, it absorbs water. Since water has a boiling point of only 212 degrees give or take, as it absorbs water it lowers the boiling point of the fluid. Some fluids cope better with this then others to a small degree but they all suffer from this to a similar extent with the exception of DOT 5 fluids. DOT 5 is also referred to as silicone fluid, and while it has issues being hygroscopic is not really one of them. DOT 5 fluids are not compatible with DOT 3, 4, and 5.1 fluids, which are mostly compatible with each other.

There are a few sites on the web that go further and explain it in greater detail. I encourage you took look. The StopTech link earlier in the thread is a good place to start.