Results 1 to 9 of 9
  1. #1
    mtbr member
    Reputation: 3fast3furious's Avatar
    Join Date
    Dec 2010
    Posts
    448

    Brake fluid question

    What's the difference between the various DOT fluids? I know that Avid suggests DOT 4 or 5.1 to bleed my Elixirs. But in my haste at the hardware store, I grabbed DOT 3. Is this a huge difference? Are my brakes gonna start on fire? I was hoping to get them done tonight, since I don't have any time over the weekend to go back to the store. Is the DOT 3 fluid acceptable or should I wait and get the right stuff?

  2. #2
    Uphill? What's that
    Reputation: Rob-Bob's Avatar
    Join Date
    Jun 2004
    Posts
    551
    I would get the right fluid.. I think the wrong dot fluid can damage the sills in your cylinders. That would be bad.

  3. #3
    mtbr member
    Reputation: mitzikatzi's Avatar
    Join Date
    Sep 2008
    Posts
    1,811
    DOT 3 was used in older cars etc. 4 just has a higher boiling point and lasts longer. 5.1 was designed for modern cars with ABS it is higher performance than 4 but adsorbs water quicker. Provided your not doing extreme downhill or anything 3 should be OK but I would change to 4 when I can. Of course I may have it all wrong.
    Duct tape iz like teh Force. It has a Lite side and a Dark side and it holdz the Universe together.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    291
    Yeah they are all based on polyethylene-glycol and the significant difference is their boiling points. I would put in dot 5.1 bc there is less chance you will roast you brake fluid. but yes technically dot 3 will work just poorly

  5. #5
    mtbr member
    Reputation: onegymrat's Avatar
    Join Date
    May 2006
    Posts
    932
    I somewhat understand the differences between DOT 4 and DOT 5.1, as the others have noted, and both will work fine with your Avid brakes. But I think the key here is that Avid specifically states it's either one of those, not DOT 3 (nor 5.0), so I would wait and get the proper fluid.

  6. #6
    mtbr member
    Reputation: 3fast3furious's Avatar
    Join Date
    Dec 2010
    Posts
    448
    Quote Originally Posted by onegymrat
    I somewhat understand the differences between DOT 4 and DOT 5.1, as the others have noted, and both will work fine with your Avid brakes. But I think the key here is that Avid specifically states it's either one of those, not DOT 3 (nor 5.0), so I would wait and get the proper fluid.

    Well, I did some research on it. Dot 3 is the same stuff, just formulated with a lower boiling point. In a pinch it will work but not recommended and will most likely burn up. DOT 5 is a big no no since it is a different substance entirely. I believe it's silicone based. But, for the record, I did wait and found DOT 4 at NAPA and grabbed that. So I'm all good

  7. #7
    mtbr member
    Reputation: Ferdball's Avatar
    Join Date
    Jan 2008
    Posts
    179
    I have Juicy 5 brakes which specify DOT 5.1. I grabbed some DOT 5 fluid at the auto parts store.

    The 5.1 is carmel in color, and the 5 is purple. The DOT 5 says that it can be added to fluid that is already there, but I added them in a bottle, and they don't seem to mix. The carmel stays at the bottom and the purple is at the top.

    Should I just go back and find some SRAM DOT 5.1?
    Don't forget to unswerve!

  8. #8
    mtbr member
    Reputation: 3fast3furious's Avatar
    Join Date
    Dec 2010
    Posts
    448
    Quote Originally Posted by Ferdball
    I have Juicy 5 brakes which specify DOT 5.1. I grabbed some DOT 5 fluid at the auto parts store.

    The 5.1 is carmel in color, and the 5 is purple. The DOT 5 says that it can be added to fluid that is already there, but I added them in a bottle, and they don't seem to mix. The carmel stays at the bottom and the purple is at the top.

    Should I just go back and find some SRAM DOT 5.1?
    Yes sir. Do not put that in your lines. Dot 5 and Dot 5.1 are way different. You would think that they would not name them so alike with the major differences. I would think Dot 4.1 would make more sense since it is the same stuff just with a different boiling point. The DOT 5 is silicone based and the DOT 5.1 is polyethylene-glycol. Not the same stuff.

  9. #9
    mtbr member
    Reputation: Ferdball's Avatar
    Join Date
    Jan 2008
    Posts
    179
    Quote Originally Posted by 3fast3furious
    Yes sir. Do not put that in your lines. Dot 5 and Dot 5.1 are way different. You would think that they would not name them so alike with the major differences. I would think Dot 4.1 would make more sense since it is the same stuff just with a different boiling point. The DOT 5 is silicone based and the DOT 5.1 is polyethylene-glycol. Not the same stuff.
    Whew! Thanks for your reply. I have sone 5.1 from Finish Line on order.
    Don't forget to unswerve!

Posting Permissions

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