Brake fluid?

Texx

Texx

Super Moderator
Been using DOT 5.1 for the last 5 years. It's brake fluid, it does the job, there's not much more to say really.
 
MarcoGTTurbo

MarcoGTTurbo

Member +
dot 4 and dot 5 are not combinable in any way! so make sure you flush out your old fluid first. dot 5 is mainly used in race applications and as we know for race cars needs to be changed regulary. dot 5 is silicon based and dot 4 polyglycol based and they are defo no mixable.

so if your gunna switch flush flush flush!

Texx - I know your gunna say u just switched or topped up with dot5 but I think with road applications you'd get away with it.
 
dark_knight

dark_knight

Member +
someone had recently done up a comparison on boiling points of the different dots of braike fluid, so i guess if you drive in a manner never to cook your dot 4 then there really isn't any need to upgrade to 5.1, is there.. or do people just do it for peace of mind..?
 
A

AdamB

Member +
Some DOT4 actually has a higher boiling point than 5.1 products, it will vary between manufactured brands as they all add their own concotion of blends lol.
As Texx said really, brake fluid is brake fluid, as long as your not cooking it on the road I don't see no reason to upgrade to a more expensive option which will never be utilized.
 
dac69er

dac69er

Super Moderator
MarcoGTTurbo said:
dot 4 and dot 5 are not combinable in any way! so make sure you flush out your old fluid first. dot 5 is mainly used in race applications and as we know for race cars needs to be changed regulary. dot 5 is silicon based and dot 4 polyglycol based and they are defo no mixable.

so if your gunna switch flush flush flush!

Texx - I know your gunna say u just switched or topped up with dot5 but I think with road applications you'd get away with it.
Click to expand...

5 and 5.1 are different. dot 5.1 isnt silicone based.
 
J

jimglanza

Member +
Cheers for your contribution lads, only asking because im in the middle of a complete brake overhaul and noticed a nice new bottle of valvoline 5.1 in the the corner of the garage so didnt know whether to stick with dot 4 or flush out and start again with 5.1?

If its only a higher boiling point and there are no gains then i may not bother.

Cheers,
James.
 
dac69er

dac69er

Super Moderator
Higher boiling point is a gain if your hard on the brakes as you won't loose your pedal as quickly when the brakes get really hot. If you don't drive on a track I wouldn't worry!
 
J

jimglanza

Member +
Well it dosen't get abused to much maybe once or twice a summer and hasn't ever really faded under the pedal so maybe stick to a good quality dot 4.

Cheers for your help.
 
R

Rev

Member +
As said Dot 4 can be higher temp but i think these are refered to as super Dot 4. These super Dot seem to vary alot I think because they come under the dot 4 standard and there is no super dot 4 standard as such.

The thing that stands out is how quickly high temp protection goes down over time and the different service life of the products -
> Not sure for 5.1 but for example Dot 3 has 100C temp drop ( ERBP ) after 1 yr which is similar to the temp drop Super Dot 4 fluid (3080) has after 2 yrs . Dot3 recommended changing is 1 yr ( increased danger of vapour lock at 2yrs ) vs Super Dot 4 (3080) recommended changing at 2 yrs ( increased danger of vapor lock at 4 yrs )

When is high temp fluid not high temp ? In the DATA sheets fine print -
> The same product had different product numbers for different sizes. The larger containers were not guaranteed to have any high temp protection eg. like the larger ones supplied to some garages.
 
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