Can I use any DOT 3 brake Fluid?

I need to bleed my front brake as they are bone dry after sitting for 15 years and was wondering if I can use normal DOT 3 automotive brake fluid or is there a special type I should use?

Dot 3 is OK; DOT 4 is "better" in that it has a higher boiling point. DOT 5.1 (note the "point one" is OK. DOT 5 is not recommended by any car manufacturer or any bike manufacturer except Harley. I guess Harley did that since they can barely get out of their own way, stopping power is not so important. It must have been more important for them to have brake fluid that won't damage paint - which DOT 5 will not. Further, Brembo does not recommend DOT 5 on any of their aftermarket systems.

http://www.motorcycleproject.com/motorc ... fluid.html :wink:

Years ago, when I put the braided-stainless brake lines on the Nort, I filled the system with DOT 5 sliicone brake fluid. 18 years later, after sitting the last 16, the brakes still function. Don't thi nk that would have been with any other DOT.

BEWARE
If you assume its been "bone dry" for 15 years.
Its not unthinkable that the caliper pucks &/or master cylinder
piston had time for condensation to rust enough to gall their bores.
It possible the hose has swelled inside or got flaky oxidized.
I'd guess extra effort and hot pad drag is most obvious annoyance.
Hope not of course and just a top off bleed down and good to stop.

Be very attentive to the brake fluid level check each gas up
next 1000 miles. Its possible to have an occult leak like
my Combat did and worked a treat till one pull down
to the next just seconds apart had no brake at all ****!
Took awhile to find at master cylinder because wind
blew fluid away and the slight drops I saw on tank seemed
like just gas to wipe off. When new paint bubbled I found the leak
and rebuilt the mess inside.

DOT 5 was first for military to store long term and then museums.
Its main feature is does not absorb water like other fluids do
till it settles in low spots. But DOT 5 still does not stop
condensation so should be checked drained every decade or
so. For street use likely only the seals standing it matter.

hobot

Any DOT 3 you get today is likely better than anything available when Commandos were new - but DOT 4 is better.

That said, the advice above is good. Seals in the brake system are likely dry and should be checked after 15 years.

Danno +1