Discussion in 'Softail Models' started by taweste, Aug 20, 2008.

  1. taweste

    taweste Member

    I stopped at a harley dealer one day because I needed primary oil and brake fluid. I did not know what type of brake fluid I needed so I asked the worker at the parts counter. She called someone for help, and after a short discussion she told me that I would need DOT4 brake fluid.

    I blead the brakes using the DOT4 brake fluid and went on vaca for about 1 1/2 weeks. I took the bike out when I got home and my brakes locked up (the rear brakes, the rear was the system I used the fluid in). The brakes caught on fire, and upon closer inspection the seals were practicaly non-existent.

    I brought the caliper to a different harley dealer, looking for a rebuild kit and to try and figure out what could have caused the problem, and they mentioned that the caliper smelled like DOT4 fluid. They asked if I had used DOT4 fluid and I told them that I had used the fluid the other dealer had given to me (at that time I wasnt sure if it was DOT4 that they had sold me). They said that under no circumstances should a harley dealer have given me DOT4 fluid for an 86' softail. The whole shop was quite surprised that they had sold me DOT4. They stated that I could attempt to THOUROUGHLY clean the system, but the best thing to do would be to replace the rear brake system.

    The next day I went back to the dealership that sold me the DOT4, and I told the parts manager what had happened. He immediately aplogized and stated that they would replace all the parts necessary to ensure the bike is safe. He also apologized stating that they were happy that no one was injured. He wanted to order a new master cylinder, but I was not sure of the manufacturer on my bike (it was aftermarket). I told him I would return the next morning with the manufacturer. He then suggested that the dealer could come pick up my bike to ensure all the work was done properly. I took him up on his offer and arranged pick-up.

    After they had my bike for about 24hrs the servoce manager called and stated that there was no way DOT4 brake fluid would cause a problem with my bike. I spoke to the store manager and he stated the same, that besides the fact that DOT4 and DOT5 seperate when combined together, it would not cause any serious problems.

    One dealer is lying to me, and/or is very ignorant when it comes to brake fluid. Can anyone tell me who is correct? Is it OK to mix DOT4 and DOT5 brake fluid (as the dealer who sold me the DOT4 fluid told me)? Or, is putting DOT4 fluid in an 86' softail VERY dangerous, as the other dealer told me?

    Lastly, will a thorough cleaning with a rebuild be sufficient or do I need to relpace the entire system?

    Thanks for Reading
  2. Bud White

    Bud White Well-Known Member Retired Moderators

    I can say dont Mix Brake Fluids as it causes seal problems .. In Cars we were always told to flush the system totally before switching brake fluid.. I cant offer if Dot 4 in the 86 softtail is Dangerous or not but bet Glider Can
  3. glider

    glider Veteran Member

    Dot 4 and 5 should NEVER be mixed. It will turn into sludge in the system like BB's. A complete disassembly and rebuild of the entire system is in order using the proper fluid for the bike. Usually the cap will tell you what is on the system on the brake cylinders.

    Here's some reading on the fluids.

    Flushing Brake Systems - Harley Davidson Community

    DOT Brake Fluids - Harley Davidson Community

    Paying Attention To Brake Fluid - Harley Davidson Community

    Mixing Brake Fluids - Harley Davidson Community
  4. taweste

    taweste Member

    Thanks for the quick reply.

    So mixing is bad, but if I asked you for the fluid for an 86 softail would you suggest DOT4?

    The dealership which sold me the DOT4 is saying that it isnt a big deal to use DOT4 on an 86 softail?

    I am going to read the links you provided, I am sure that will answer my questions.

  5. glider

    glider Veteran Member

    I believe it may be 4 but not absolutely sure on an 86. Check the cap on the cylinder, it should tell you or the owners or factory manual will tell you also.

    YES, mixing is VERY bad.
  6. Apyle

    Apyle Junior Member

    In my 1987 fxrs it says right on the master cylinder caps DOT 5 only.
  7. SledDog

    SledDog Senior Member Staff Member Moderator

    DOT 5 is standard for that year. Most, if not all, after market brake parts for that year are DOT 5. You said the bike was custom build. So we can assume (yea...I know...) that the brake fluid requirement was DOT 5.

    As other have said, mixing is a no no. You can change to another form of fluid, but the seal must be able to handle it. And you must flush the system. DOT 5 does not destroy your paint job as DOT 3 would...
  8. krikket

    krikket Active Member

    DOT 5 was originally introduced as a racing brake fluid due to its very high boiling point. However, DOT 5 is a silicon based fluid, which means its not practical for constant use because silicon does not absorb moisture. Any moisture will remain as water and corrode metal parts, and since no brake system is truly "sealed," the fluid requires more frequent changes.

    DOT 4 is a glycol based fluid which is hygroscopic (water absorbing). As the fluid absorbs moisture, the fluid's boiling point drops significantly and can produce air bubbles in the system as the brakes heat up (from exhaust or just using them a lot).

    What relevance does this info have? From what I've seen, seals made for one brake fluid cannot be mixed with others and will distort, deteriorate and crack. Harley's may have seals that can tolerate both type of fluids, but I doubt it. If the brake locked and caught on fire, they were so hot the seals wouldn't have survived anyways. So, for the dealer to say the brake fluid wasn't the cause is pretty far-fetched.

    NEWHD74FAN Experienced Member Retired Moderators

    Krikket & Glider have it right exactly...DO NOT MIX SILICONE BASED DOT 5 with GLYCOL BASED DOT 4 EVER!!! DOT 4 is the highest temp rating for Glycol (old technology brake fluid) used primarily in Disc brake systems; DOT 3 was used in older Drum brake systems...think automotive technology here. Motorcycles are generally in a higher state of tune and much greater horsepower to weight density/ratios so you read your manual. DOT 4 contaminated his DOT 5 system, he must replace everything nitrile or rubber including hoses! :bigsmiley15:
    Last edited: Sep 1, 2008
  10. taweste

    taweste Member


    After doing some research and with the help of some forum members, I came to the conclusion that when DOT4 and DOT5 brkae fluid is mixed, some people say flushing the system will be fine, some say a rebuild with a flush is necessary, and other suggest replacing the entire brake system.

    I told the store manager this and said that all they were willing to do is flush the system. I was fine with that as long as he put it in writing that the proper remedy for such a problem would be too flush the system. He adamantly refused to put ANYTHING in writing. I said would trust his professional opinion, but I just wanted his remedy in writing. He continued to refuse to put anything in writing, and said that instead "he knew what I was up to" and would replace my rear brake system. He still refused to put anything in writing. I ended the conversation, frustrated that he would not stand by his word, but happy that the brake system would be replaced therefore eleminating any possible problems in the future.

    About a week later they called and said my bike was finished and that I would have to pick it up (its about an hour drive). They refused to deliver my bike back even though they suggested to pick it up in the beginning, which they did. I agreed, and was actually happy to drive it home since it was a nice day and I hadnt had my bike in awhile.

    When I got to the dealership, I quickly realized that they had NOT replaced the brake system. They rebuilt the caliper and master cylinder, and replaced the line. I was handed a reciept which stated that they did not test ride the bike, and that the bike had numerous safety issues. I asked the gentleman at the service counter if it was standard procedure to not test ride bikes, and give a bike back to a customer which has "numerouse safety issues." I informed him that I would be back to speak with the store manager AGAIN.

    At this point I am going to send a letter to the appropriate authorities, the BBO, and Harley Corporate. I am filing a suit against the store manager in his individual capacity, since he is the one who began the negligence, and ensured I was not treated properly (the parts manager was very helpful, and the store manager is blaming him for promising to fix my bike), for the money it would cost to replace the rest of the system. I would have been happy if he would have told me what he was going to do, and put it in writing, not lie to me.

    I am extremely angry with the general manager, after his honest employee tried to remedy the situation he lied and gave me a bike with "numerous safety issues."

    Here is the address to the dealership. STAY AWAY, THEY ARE NOT RELIABLE!!!

    Sheldon's Harley Davidson
    914 Southbridge Street
    Auburn, MA 01501

    The store managers name is Ed. He is the one who is lying and causing problems.

    Shayne is the parts manager, he was very helpful and is being portrayed as the bad guy by Ed.

    Please feel free to call the store and speak to Ed and vouch for Shayne. I really hope they don't try to discipline him for any of this. He is a genuinely honest individual. Or just call to state that you will not be using their service.

    Thanks for your time in reading this, my number is 774-364-0659, please call me if you have any suggestions, or if you have ever had any similar situations. I will do all I can to ensure they dont do this to anyone else.