Is All Dot4 Created Equal?

yip, just make sure it's fresh from a sealed container

 

500ml should be enough. brake fluid is hydroscopic (think thats the word)absorbs moisture from the air and lowers the boiling point of the fluid. if its sealed it wont.

 

In the absence of Speed Trips: it's Hygroscopic

 

I have genuine Agip stuff..............seems to have mixed OK with some cheaper D4 stuff.....

 

just don't mix dot 4 with dot5
yes hygro not hydro made that mistake myself
suppose associate hydro with water

 

1

 

You sure it's not hydromatic? Absolutely sure?

 

A bit expensive. Look for Shell Advance from Smith & Allan on eBay. They sell multiple 500ml bottles very cheap. I bought DOT 5.1 from them. Safe to mix with DOT 4. DOT 5 is different and to be avoided.

 

Agree with the above. If you're tracking and real heavy on the brakes some of the DOT 4s are different they are not all created equal. I think it's generally the boiling point (higher the better). Some DOT 4 is better than 5.1 so I've been told.

If its for road use almost any 4 or 5.1 will be fine. As @Recidivist said avoid 5.0 like the plague its a totally different animal and to be avoided at all costs

 

DOT 5 is silicone based. It was designed for rally cars back in the 1980s. DOT 4 and 5.1 are synthetic.

 

dot 5 is designed not to as hygroscopic as dot 3. 4. 5
but if mixed will eat rubber seals
told it was designed for military vehicles that stand for periods of time
some classic car enthusiasts use it for cars that are laid up unused over winter
I had to deal with a triumph gt6 that had dot 5 in the brake and clutch system
new owner not knowing anything about brake fluids just topped up with well anything to hand
had to replace most of the system
oh and dot 5 is pricey I believe

 

Thanks, that's a great deal, very cheap, and yes dot 5 is to be avoided.

What is the Difference between DOT 4 and DOT 5.1 Brake Fluid? | Epic Bleed Solutions

 

Well it's one more, isn't it...

 

I have Dot 5 in my clutch...it doesn't seem to work properly otherwise. and it stains the resevoir purple...which is nice.

 

All DOT4 is definitely not created equal.

Used to use the Halfords own brand and after three laps on the track, the lever cam back to the bar on my ZXR-R.

Switched to Rock Oil Dot4 and never had the problem again.

A

 

The brake fluid – do we know enough about it?