Dot 5 brake fluid

[nealblath]

anyone ever used it in a Z?

supposed to be non corrosive, ie, won't damage paint. Just wondered because I have had to touch up the paint on the calipers already where a small amount of fluid drippeed onto the calipers while bleeding them.

not recommended for ABS brakes but should be fine on a Z

[Eric Frith]

Dot 5 is non corrosive and will not harm the paint, Dot 5.1 is corrosive though.

I use Dot 5 wherever possible

[nealblath]

Dot 5 is non corrosive and will not harm the paint, Dot 5.1 is corrosive though.

I use Dot 5 wherever possible

yes I noticed that Eric.........apparently 5.1 has additives that make it corrosive

just ordered a bottle of Dot 5

[zed1015]

You can't just re-bleed the system with dot 5.
You must totally strip the braking system and remove all traces of dot 4 if going over to 5.
Also you will most likely have to replace all the seals too in the calipers and master cyl.
4 and 5 don't play well together (glycol v/s silicone) and will mix to form a sludge even in the tiniest amounts.

[nealblath]

You can't just re-bleed the system with dot 5.
You must totally strip the braking system and remove all traces of dot 4 if going over to 5.
Also you will most likely have to replace all the seals too in the calipers and master cyl.
4 and 5 don't play well together (glycol v/s silicone) and will mix to form a sludge even in the tiniest amounts.

ok Rob........will strip system fully down first

[Rich]

seconded for new seals and full strip

[jimmock]

seconded for new seals and full strip

I quite fancy the "full strip" part!!


Jimmock.

[Garn 1]

NealB, a question I have often asked and never received a logical answer.
If dot 5 is so good, why doesn't all new bikes have it?
Perhaps, it is as you say "not recommended for ABS brakes".
Is that the only reason?
RegardZ

[HowieD]

There are some explanations here:

http://moodle.student.cnwl.ac.uk/moodledata_shared/cdx%20etextbook/dswmedia/brakes/brake/comp/brakefluid.html

http://www.bikersoracle.com/gs/forum/showthread.php?t=470

I still use DOT4 on my completely new brakes and Hyd Clutch..

regards
Howie

[Garn 1]

Thanks HowieD, good explanations, particularly from BMW GS forum. I'm in the market for a F800Gs 2009 -2010... one day!
RegardZ.

[gray]

On the other hand....
15 years ago I owned a Corvette stingray ( '69 L46 350/350 smallblock T roof) with terrible caliper corrosion so I got a stainless calipers kit from the US. Came with litres and litres of silicone brake fluid and I had plenty left over at the end so i got most of the old fluid out of my Z9 and refilled with the new stuff.
No problems at all , and it didn't "age" and go murky and cloudy like Dot 3/4 does. No problem with the seals and I wasn't superfastidious about the changeover. only went back to dot4 when i ran out of it .( so that was 35-40K miles of use.)

[hx35w]

NealB, a question I have often asked and never received a logical answer.
If dot 5 is so good, why doesn't all new bikes have it?
Perhaps, it is as you say "not recommended for ABS brakes".
Is that the only reason?
RegardZ

Dot 5 will be spongy because it will compress more than glycol based fluid.
Dot 5 is more likely to draw more condensation than other fluids.
Dot 5 is prone to having microscopic bubbles more easily in-trained witch adds to the spongy feeling. Not to mention, It's not cheap.

Does have a higher boiling point.
It also works as a grate replacement for armor all. It will last much longer and make rubber,vinyl, and engine paint look new.