I need tips on bleeding Formula K24 brakes please- Mtbr.com
Results 1 to 10 of 10
  1. #1
    Nat
    Nat is offline
    mtbr member
    Reputation: Nat's Avatar
    Join Date
    Dec 2003
    Posts
    13,174

    I need tips on bleeding Formula K24 brakes please

    After trying some five or six times to get air out of the line on my rear K24, I still have air in the line. I laid the bike flat on its right side so the caliper was horizontal and angled the lever to vertical at about the same height off the floor as the caliper. I did not see any air in the line as I withdrew the syringe plunger, or when I cycled the DOT fluid back and forth. Can you guys give me any hints?

    Also, you know that teeny-tiny microscopic o-ring under the grub screw? That thing's a dick!

  2. #2
    banned
    Reputation: Jerk_Chicken's Avatar
    Join Date
    Oct 2005
    Posts
    16,457
    You don't want the lever and caliper at the same height. That would likely cause an occlusion of the air in the lines. You want the air bubbles to move to one end or the other via buoyancy, as well as force.

    Don't forget to tap and tip the caliper, as it's got an annoying pocket where bubbles like to stick.

  3. #3
    Nat
    Nat is offline
    mtbr member
    Reputation: Nat's Avatar
    Join Date
    Dec 2003
    Posts
    13,174
    Quote Originally Posted by Jerk_Chicken
    You don't want the lever and caliper at the same height. That would likely cause an occlusion of the air in the lines. You want the air bubbles to move to one end or the other via buoyancy, as well as force.

    Don't forget to tap and tip the caliper, as it's got an annoying pocket where bubbles like to stick.
    Thanks. I'll mount the lever higher up than the caliper next bleed. Tip the caliper which way?

  4. #4
    banned
    Reputation: Jerk_Chicken's Avatar
    Join Date
    Oct 2005
    Posts
    16,457
    With the line fitting a slight bit up towards the ceiling to get the bubble out of the pocket, then up into the line. I learned this on the Avid Juicy, which was designed and originally manufactured by Formula as well. The Oro has a similar pocket in my experience.

  5. #5
    Nat
    Nat is offline
    mtbr member
    Reputation: Nat's Avatar
    Join Date
    Dec 2003
    Posts
    13,174
    Quote Originally Posted by Jerk_Chicken
    With the line fitting a slight bit up towards the ceiling to get the bubble out of the pocket, then up into the line. I learned this on the Avid Juicy, which was designed and originally manufactured by Formula as well. The Oro has a similar pocket in my experience.
    Cool, I'll try it.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    13

    More ORO K24 bleed questions

    The front brake is working superb...

    However, I too have had problems bleeding my rear K24. I have noticed the bleed instructions I got with the brake are slightly different to those on the US website.

    Does it matter what position the FCS lever is in during the bleed?
    During the suction phase is it easy to suck air back in to the system?

    I tried tapping the caliper. Would it be best to take the whole brake off the brake so I can get the hose vertical with the caliper at the bottom and the lever at the top?

    Any more tips would be superb.

    cheers

  7. #7
    Nat
    Nat is offline
    mtbr member
    Reputation: Nat's Avatar
    Join Date
    Dec 2003
    Posts
    13,174
    Quote Originally Posted by dannyboy
    The front brake is working superb...

    However, I too have had problems bleeding my rear K24. I have noticed the bleed instructions I got with the brake are slightly different to those on the US website.

    Does it matter what position the FCS lever is in during the bleed?
    During the suction phase is it easy to suck air back in to the system?

    I tried tapping the caliper. Would it be best to take the whole brake off the brake so I can get the hose vertical with the caliper at the bottom and the lever at the top?

    Any more tips would be superb.

    cheers
    I also noted the two sets of bleeding instructions.

    During suction phase I did not get air bubbles once I removed the teeny-tiny grub screw o-ring and tightened the metal chucks (things at the end of the syringe hose) to the system.

    Did you lose your teeny-tiny grub screw o-ring?

    I laid my bike horizontal and mounted the handlebar vertically in the workstand. I then just tilted the frame up towards the ceiling to tap on the caliper. I think I got it this time (finally).

  8. #8
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    13
    The T10 'grub screw' on the lever had the o-ring attatched to the screw. The o-ring at the caliper I never removed. I just removed the little T10 'plug' and just screwed the bleed adapter in on top. I didnt actually see the o-ring located here but presume it is in place. Was this my mistake?

    Thanks

  9. #9
    Nat
    Nat is offline
    mtbr member
    Reputation: Nat's Avatar
    Join Date
    Dec 2003
    Posts
    13,174
    Quote Originally Posted by dannyboy
    The T10 'grub screw' on the lever had the o-ring attatched to the screw. The o-ring at the caliper I never removed. I just removed the little T10 'plug' and just screwed the bleed adapter in on top. I didnt actually see the o-ring located here but presume it is in place. Was this my mistake?

    Thanks
    The teeny-tiny o-ring at the caliper grub screw is freely-floating and displaces easily. Mine fell out onto the garage floor three times and by some miracle I found it each time. I don't think there's supposed to be an o-ring at the lever end other than the one attached to the T10 screw.

    I think you have to use both syringes at either end of the system to bleed the brakes. Using both syringes lets you push fluid through the system, otherwise with one end closed fluid isn't going to flow anywhere. Look at me, talking like a Formula brake expert now that I've fumbled through it a couple of times. Can any real experts confirm?

  10. #10
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    13
    Took some advice from a friend who knows motorbikes and tied a zip tie around the bar and brake lever and left overnight tightened up. Dont know how but seems to have made the brake less spongy.

Members who have read this thread: 0

Posting Permissions

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

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.