Results 1 to 4 of 4
  1. #1
    mtbr member
    Reputation:
    Join Date
    Mar 2004
    Posts
    64

    Upset Bled with wrong brake fluid. Now what?

    Hey all,

    I have a set of Mono Minis and I just rebled the rear brake. Hope recommends that I use DOT 5.1 or 4 fluid. However, I misread that and used DOT 5 fluid instead. A day after bleeding the brakes with the wrong fluid, I realized my mistake. (Yes, I'm an idiot.) Of course, I also find out that DOT 5 and DOT 5.1/4/3 are incompatable. Joy. I was so proud of myself too for bleeding my brakes too.

    Anyway, I haven't ridden on my bike yet since my brakes have been bled. I've read from other posts that I should just use DOT 4, since DOT 5.1 is impossible to find. (It actually took me a while to find DOT 5, and I didn't see DOT 5.1 anywhere.)

    My question is: do I just need to do a full rebleed of my brakes with DOT 4 fluid to fix everything? Or are my brakes completely screwed? Will I need new seals and lines, etc.? My brakes FEEL okay at the moment. They haven't exploded, aren't leaking, or doing anything else suspicious or unusual.

    Thanks for the help.


    EDIT: Hrm, I just read that people who changed their cars' brake fluid from DOT 5.1/4/3 to DOT 5 may be making things worse by going BACK to DOT 5.1/4/3 as the silicone in DOT 5 fluid is nearly impossible to get out of the system. Arrgh. Should I even rebleed them at all? At least it's just my rear brake, heh.
    Last edited by Freshies; 08-24-2004 at 09:48 PM.

  2. #2
    (aka SS_MB-7)
    Reputation: 1speed_Mike's Avatar
    Join Date
    Jan 2004
    Posts
    924
    Quote Originally Posted by Freshies
    My question is: do I just need to do a full rebleed of my brakes with DOT 4 fluid to fix everything? Or are my brakes completely screwed? Will I need new seals and lines, etc.? My brakes FEEL okay at the moment. They haven't exploded, aren't leaking, or doing anything else suspicious or unusual.
    Flush the system completely of the DOT 5 fluid. Then, re-bleed with DOT 5.1 or DOT 4 fluid. Flush the system completely again. Re-bleed again with DOT 5.1/DOT 4. That should do it. If in doubt, call Hope USA.
    Ride Hard,
    Mike B. (MCM# 7.77)
    http://www.one-speed.com

  3. #3
    mtbr member
    Reputation:
    Join Date
    May 2004
    Posts
    104
    Hope's website states that the seals were probably damaged by using the wrong type of fluid. They recomend sending the brake in so the seals can be replaced. Still send them an email to check it out.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Mar 2004
    Posts
    64
    Well, I flushed out all the DOT 5, flushed a couple reservoirs full of DOT 4 through the system, and then bled them. The brakes seem to be holding up ok. They worked so far on my first ride, and I haven't found a puddle of DOT 4 on the ground by my bike yet (/knock on wood). Hopefully the silicone stuff didn't cause too much damage since it was only in for 2 days. I'll probably rebleed them in a month or so, just to be safe.

    Thank god it was just my rear brake--I'd be a lot more nervous if it were my front.

    Thanks for the help. Who knew that US government standards could be so confusing!

Similar Threads

  1. Shimano mineral brake fluid: hygroscopic?
    By Wombat in forum Brake Time
    Replies: 3
    Last Post: 08-22-2004, 11:40 AM
  2. Magura brake fluid question?
    By texheckler in forum Downhill - Freeride
    Replies: 8
    Last Post: 07-30-2004, 08:05 AM
  3. alternative for shimano brake fluid
    By ttown in forum Brake Time
    Replies: 1
    Last Post: 06-28-2004, 07:22 AM
  4. Marta SL bleeding - what am I doing wrong?
    By AnoBlur in forum Brake Time
    Replies: 3
    Last Post: 03-28-2004, 05:52 PM
  5. Total loss of brake power, what's wrong?
    By COmtbiker12 in forum Brake Time
    Replies: 1
    Last Post: 01-16-2004, 05:43 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •