Front Range 4x4 Upcoming Trail Runs - Add a New Trail Run

Results 1 to 5 of 5

Thread: DOT 5 Brake Fluid

  1. #1
    Join Date
    Mar 2008
    Member
    #110
    Last Online
    April 6th, 2019
    Location
    Morrison, CO
    Age
    49
    4x4
    Toyota/Scout/Nissan
    Posts
    4,961
    User Name
    Patrolman
    Real Name
    Jeff
    Thanks Given
    182
    Thanked 346 Times in 298 Posts

    Default DOT 5 Brake Fluid



    I had never heard of DOT 5 until watching MotorWeek (episode 3425) yesterday. It is apparently a new brake fluid, which unlike other types, does not attract moisture. That means that the brake components can last longer, and the fluid can remain in the system longer.

    Important to know though is that it apparently will not work with ABS brake systems as it will bubble. This means that can likely only be used in older vehicles (a plus for me) or in hydraulic clutch systems. My understanding is that it can be used in any system requiring DOT 3 or DOT 4, but again, not in ABS. It is also considerably more expensive, but if it lasts longer, over the long run it may end up cheaper. Oh yeah, and it is PURPLE!

    Here is some good info:

    http://en.wikipedia.org/wiki/DOT_5

    http://www.motorweek.org/features/go...fluids_and_abs

  2. #2
    Join Date
    Nov 2010
    Member
    #748
    Last Online
    June 26th, 2022
    Location
    denver co
    4x4
    94' toyota PU, 89 yj
    Posts
    2,258
    User Name
    94ToyBear
    Real Name
    Adam
    Thanks Given
    107
    Thanked 153 Times in 120 Posts

    Default Re: DOT 5 Brake Fluid



    I heard new Harleys use dot 5, from my understanding it's for High temp break systems and will only work for dot 5 applications only no dot 3 or 4 is compatible because it's a silicone base fluid.

    BUT I might be of on the facts. I never used it in an automotive application.

  3. #3
    Join Date
    Mar 2008
    Member
    #110
    Last Online
    April 6th, 2019
    Location
    Morrison, CO
    Age
    49
    4x4
    Toyota/Scout/Nissan
    Posts
    4,961
    User Name
    Patrolman
    Real Name
    Jeff
    Thanks Given
    182
    Thanked 346 Times in 298 Posts

    Default Re: DOT 5 Brake Fluid



    This is what was quoted in Wikipedia, and as we know, everything on the internet is always correct.

    "Using DOT 5 in a DOT 3 or DOT 4 system without proper flushing will cause damage to the seals and cause brake failure. DOT 5 brake fluid is not compatible with anti-lock brake systems."

  4. #4
    Join Date
    Sep 2011
    Member
    #921
    Last Online
    5 Hours Ago
    Location
    Fort Collins
    4x4
    1990 Jeep Wrangler (YJ)
    Posts
    10,057
    User Name
    Jim
    Real Name
    Jim Williamson
    Thanks Given
    2,462
    Thanked 3,008 Times in 2,005 Posts

    Default Re: DOT 5 Brake Fluid



    I ran DOT5 / Silicone in my 68 Ford Ranch wagon - after I replaced all four wheel cylinders (and maybe the master cylinder) - the whole system was flushed and contained only DOT 5 when it was ready for use.

    The two highlights is that (I think) it has a higher boiling temp (good for racing - not so much of a need on a station wagon [though it was heavy]) and it is not ?hydro-scopic? which means "attracts water".

    It's the issue of not attracting water and thus a reduction of having rust form in the wheel cylinder walls / pistons and having a smoothly operating brake system was my goal.

    Yes, it can't be mixed with DOT 3 / 4 (at least not when I had the car in the 80's/90's) and the fluid came with a large "STOP" sticker to be placed near the master cylinder so that DOT 3/4 would not be added on a top-off.

    Not damaging paint was a plus, but not an important one. There was one time I spilled a bit on the fender so I simply wiped it all over the fender top - it made the old, flat, weathered paint shine nicely - and never damaged it.

    I sold the car and never had any wheel cyl issues - but perhaps I didn't have it long enough that I'd have issues anyway.

  5. #5
    Join Date
    Aug 2012
    Member
    #1076
    Last Online
    June 28th, 2022
    Location
    Thornton
    4x4
    1999 XJ, 1999 F 250
    Posts
    1,141
    User Name
    carpenle
    Real Name
    Levi
    Thanks Given
    276
    Thanked 125 Times in 107 Posts

    Default Re: DOT 5 Brake Fluid



    I have used dot 5 on motorcycles.

Similar Threads

  1. B&M Fluid Coolers
    By Serious Offroad in forum Vendors
    Replies: 4
    Last Post: February 26th, 2014, 07:02 PM
  2. Replies: 0
    Last Post: January 4th, 2012, 07:42 AM
  3. Home Brew Fluid Filter
    By Cr33p3r in forum Tech How To
    Replies: 2
    Last Post: December 2nd, 2011, 09:06 PM
  4. Homemade Penetrating Fluid
    By Brody in forum Tech How To
    Replies: 0
    Last Post: May 27th, 2010, 09:14 AM
  5. Manual Trans Fluid
    By KnuckleHead in forum General 4x4 Tech Topics
    Replies: 9
    Last Post: November 7th, 2009, 05:38 AM

Posting Permissions

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