Dot 5 Brake Fluid??

Discussion in 'Other Service and Maintenance' started by Beachbumz327, Dec 28, 2013.

  1. Beachbumz327

    Beachbumz327 Member

    Hi Everyone, I have been trying to fix an issue I am having with my front brakes controls and today I noticed that my fluid is leaking from the reservoir around the seal of the eye glass on my '94 Sportster and was almost empty. I know I need a new eye glass installed to stop the leaking but my question pertains to the fluid itself. I noticed on the reservoir cap it reads "Use ONLY Dot 5 Fluid", ok, so I run out to the local parts store and they only have one bottle of Dot5 Silicone brake fluid, so I pick it up. I head out to the parking lot and begin to top off the the reservoir but when I started pouring in the new, it was purple!! Now, I may be in the dark here but is this correct or does my bike possibly have Dot 3 or 4 in it prior to my buying it? The fluid in there now is clear as new oil but this new stuff is purple, kind of threw me for a loop. Needless to say I stopped putting it in after I noticed the drastic difference and wanted to ask from you all what might be the reason. Thanks for all replies.
  2. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

    You should be using dot 5 brake fluid and it is purple when new however the colour can fade near clear if it has been in there for a while
    However it is possible that a previous owner has seen fit to replace the brake fluid with dot 4
    Best thing to do is replace the brake fluid with dot 5 to be sure of what you have as a mix of 4 and 5 does not work
    If you have a leak of fluid around the sight glass then if glycol based fluid dot 3 or 4 then the paint that the fluid touches would blister and peel if there is no blistering of the paint then I would assume that dot 5 is in the brake system
    It has been a wee while since I last stripped a brake reservoir but the sight glass is slightly tapered and is just pushed out but I can not remember if you push it out or in to remove it replace the rubber seal and refit the glass fill and bleed the brake system

  3. stray dog

    stray dog Junior Member

    Sounds like a good time to bleed your brake system(s) complete. Meaning keep bleeding untill fresh fluid is coming out of the caliper(s).
  4. Jack Klarich

    Jack Klarich Guest

    Dot 5 fluid is alot more slippery to the touch, when it starts to go bad it crystalises and you nay see some of the silicone floating in the master
  5. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

    If you have access to a vacuum style brake bleeder. Use it to pull all the old fluid out until you get clean new fluid. Or just bleed until clean.