Question about brake fluid

Discussion in 'Tech Forum' started by Jgelack, Mar 16, 2020.

  1. Jgelack

    Jgelack New Member

    I try to change my brake fluid every spring. Since I'm planning on taking my bike to the track this year, Ive been trying to decide if I should change to another brand. I've been running Amsoil for a couple of years, but have considered switching over to Maxima Racing fluid or the Motul rbf600. My question is, which is more important, the dry or wet boiling point of the brake fluid? Thanks!
  2. tdelegram

    tdelegram Control Rider

    Run the rbf, it’s great stuff and I have seen more people running it over any other brand, just in case you need some at the track!
  3. bmart

    bmart Control Rider

    I have been running regular old Valvoline for decades and have never had any issues of any kind. And it is very cheap and available. I change mine just before the season, and again in the middle of the season.
  4. HondaGalToo

    HondaGalToo Control Rider

    Another vote for the Motul RFB600. Been running it for years. It has a higher boiling point than other DOT 4s.
    When you're looking at different brake fluids, I'd imaging the boiling point on the container is the dry boiling point, so I guess I'd go by that when selecting which fluid, as on the track, I'd want one with a higher boiling point.

    Agree with bmart - change beginning of the season, then halfway through. Well, the front brakes anyway, lol. I think I still have the original rear pads.
  5. bmart

    bmart Control Rider

    Pads are another story. I (sadly) fun my fronts until they stop working (no pad left on the first of four), or darn close. I have enough miles to know when that is, so it is never a surprise.
    HondaGalToo likes this.
  6. vinny337

    vinny337 Vin is in...Beastmode! Control Rider

    I've used Valvoline, Maxima Racing fluid and I currently use Motul RBF600, they'll all work for you. The one thing I do is bleed my brakes and clean my caliper pistons before each race/trackday weekend.
  7. bmart

    bmart Control Rider

    :like: Cleaning the pistons and ensuring free movement is critical. Without that, all of the brake bleeding in the word won't help.
    vinny337 likes this.
  8. 2blueyam

    2blueyam New Member

    Since I got my Magura MC, I change fluid annually and have not needed to bleed mid season on my 2003!R1. Rock solid lever the whole time. I clean the pistons annually.

    My newer to me 2004 SV650 is proving to be more of a pain, even with a Magura. Might have to bleed it each weekend or get some adaptors and 4 pot calipers.

    RBF660 for me. Yeah, it costs more, but that cost is lost in the noise for a track day budget.
  9. Jgelack

    Jgelack New Member

    Thanks for all the great advice! Looks like I’m going to try the Motul RBF 600. The Maxima has a slightly higher dry boil temp, and the Amsoil has a slightly higher wet boil temp. But the Motul has a TON of good reviews, so it seems most people are happy with it. The one thing I heard was that it tends to absorb moisture and turn dark quicker than other brands. Have you guys that use the Motul find this to be true?
  10. Jgelack

    Jgelack New Member

    To clean the caliper/piston, are you just removing the caliper/pads and spraying everything down with brake cleaner, then just reassembling?
  11. bmart

    bmart Control Rider

    Motul makes great products. I'd challenge that reviews of "I love my brake fluid" aren't the same as it actually working better. Social media and voting has really put a crimp in the world of facts. :) (off soap box)

    Quick note: With regard to maintenance of the braking system. Think about it like this, you have the fluid system, which you'll be flushing to remove debris and air, and you have the mechanics of the system.

    The mechanics are things like the pivot at the lever, which should be clean and lightly lubed to work freely. The piston in the master should move easily and smoothly.

    The pads should have enough pad on them and should be clean of debris and fluids. I clean mine with the brass brush to make them look like new before reinstalling. The calipers themselves are primarily a metal hollow to hold fluid as the brake caliper pistons and pads move in and out. The pistons should be clean as should the O-rings. An easy way to do this is to but a "pad replacement" where the pads go. That can be old pads or a piece of wood that won't damage anything.

    Cycle the brakes so that the pistons move in around the "pad replacement." Note that you don't want air in the system from the top (don't overflow as you'll be pushing all of that fluid back up at the end). Be sure that the pistons don't pop out, or you'll be bleeding a dry system and cleaning up a mess. With the pistons pushed out, you'll see all of the crud on the pistons and the O-ring.

    Use something rubber friendly to clean all of that with a toothbrush. I use Simple Green, at the suggestion of a world renowned expert, but like anything, you'll find people on their soap boxes about how bad that is. Use what you're comfy with. Rinse with water or brake clean.

    Once done with that step, the pistons should move freely with one finger. That is how you know you've got it right. Note that pushing them in can overflow the reservoir. From there, reinstall pads/pins/locks and flush the system. The test. Id you've never done it, you'll likely discover a night-day difference.
  12. vinny337

    vinny337 Vin is in...Beastmode! Control Rider

    I only do the complete disassemble of the calipers/pistons/pads over the winter. During the season before each weekend I use a soft toothbrush with dish detergent, remove my brake pads, clean my pistons and bleed them to ensure I have no air bubbles. To each its own but I don't use brake cleaner because they are tough on your seals.
  13. vinny337

    vinny337 Vin is in...Beastmode! Control Rider

    Yes, I experience that with all the brake fluids I've used. For me its cheap insurance when you bleed more often, also you use up the fluid sitting on your shelf that you should dump after a year.
  14. tdelegram

    tdelegram Control Rider

    Simple green is a good alternative to brake parts cleaner, it’s not hard on seals, cheap, and get the job done.
    vinny337 likes this.

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