DOT4 or DOT5

[mobile mouse]

Hi,
After fitting braided hoses to the front.


Can you use DOT5 brake fluid or is this over the top or a good upgrade.

[mickvp]

unless you have flushed out ALL the old brake fluid, I wouldnt put DOT5 brake fluid in...

DOT5 brake fluid is silicone based, as opposed to DOT4 being Glycol based: the two are not interchangeable/cannot mix.

Also, DOT5 is not rated for any kind of Track use due to its lower boiling point (in comparison with DOT4), so if you plan on doing a lot of heavy braking or track work, I would stick with DOT4 

Unless of course you mean DOT5.1, which is a different beast entirely and probably is a worthwhile upgrade (DOT 5.1 is also glycol based, and so can mix somewhat with DOT4 just to add to the DOT4/5 confusion!)

You can find a pretty good explanation of the various DOT brake fluids from Opie Oils

HTH

Mick

[JoeRock]

Personally I'd still stick to Dot 4. Unless you ride a lot on track, braking heavily (and I mean SERIOUSLY heavily), you won't need the higher boiling point of the 5.1. You also have to bleed 5.1 more as it absorbs water quicker. You'd be much better off just getting a good 4 instead IMO

[Dead Eye]

The Opie Oils article is good, I've read it before

If you want higher performance then there is a high spec / race DOT 4 variant which has a higher boiling point

[mobile mouse]

Filled with DOT 4.
Did not look to get a hard brake lever after filling and bled both calipers.
So stopped parked bike in garage and tied brake lever back.


Two hrs later went back and what a difference I now have a good firm brake lever.


Thanks for the advice I already had the DOT 4 didn't know the difference with the DOT5 and DOT 5.1 until reading the Opei Oils article.
Maybe next time I may consider DOT5.1.

[69oldskool]

..... You also have to bleed 5.1 more as it absorbs water quicker. You'd be much better off just getting a good 4 instead IMO

That's worth knowing.
Cheers. back to dot 4 next time methinks.