Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: caliper piston movement!!!..........Help

  
  1. #1
    Status
    Offline
    KevT.'s Avatar
    Yorkshire RO
    Join Date
    Jul 2005
    Location
    Bradford
    Posts
    9,218
    Mentioned in
    7 Post(s)
    Quoted
    15 Post(s)

    caliper piston movement!!!..........Help

    hi
    Tomorrow i am changing disks and pads on my dads astra mk4 and i was just wondering if it is ok to winde the pistons in the caliber back slowly and just let the brake fluid go back to the resevoir or if you need touse the bleed nipple?

    I know on the mk3 astras you have to open the nipple otherwise you fold the seals in the master cylinder as i did that on my last car.....oops

    Any help will be most apprichiated thanx

    AOC top 15 car at PVS 2009 & 2010
    313.7bhp/343Ibft


  2. #2
    Status
    Offline
    Ffoeg's Avatar
    2170:01:06
    Join Date
    Jun 2003
    Posts
    34,591
    Mentioned in
    2 Post(s)
    Quoted
    0 Post(s)
    It's a better option to undo the bleed nipple to let the excess fluid out as you wind them back, as it can force the seal in the master cylinder to flip over if you don't.

    Plus you'll be expelling and deteriorated fluid out form near the caliper

  3. #3
    Status
    Offline
    KevT.'s Avatar
    Yorkshire RO
    Join Date
    Jul 2005
    Location
    Bradford
    Posts
    9,218
    Mentioned in
    7 Post(s)
    Quoted
    15 Post(s)
    will i need a special tool to clamp the brake hose or will some vise grips do it?

    if so is there any chance of me nackering the brake hose?

    cheers

    AOC top 15 car at PVS 2009 & 2010
    313.7bhp/343Ibft


  4. #4
    Status
    Offline
    pardoe16V's Avatar
    AOC Obsessed
    Join Date
    Apr 2005
    Posts
    3,223
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    best useing the pinch tool if youve got one, but your not taking the brake hose off are you????

    MK4 1.8 16V Sport and MK5 CDTi Estate




  5. #5
    Status
    Offline
    Ffoeg's Avatar
    2170:01:06
    Join Date
    Jun 2003
    Posts
    34,591
    Mentioned in
    2 Post(s)
    Quoted
    0 Post(s)
    You shouldn't need to clamp the hose at all, as you're not disconnecting it.

    Just get an old jam jar with some clean brake fluid in it (just a few inches), and a length of clear tube to reach from the nipple to the bottom of the jar. As you wind the caliper back the fluid will go down the tube. Make sure the end off the tube is under the surface of the fluid at all time

    But remember to bleed them again when it's all back together just in case any air got sucked back in

  6. #6
    Status
    Offline
    KevT.'s Avatar
    Yorkshire RO
    Join Date
    Jul 2005
    Location
    Bradford
    Posts
    9,218
    Mentioned in
    7 Post(s)
    Quoted
    15 Post(s)
    so no brake fluid will come out of the nipple from the hose when you open the nipple as long as the footbrake is not pressed?

    what is the brake system like to bleed as i know the mk3 was a pain in the ass!

    cheers

    AOC top 15 car at PVS 2009 & 2010
    313.7bhp/343Ibft


  7. #7
    Status
    Offline
    Ffoeg's Avatar
    2170:01:06
    Join Date
    Jun 2003
    Posts
    34,591
    Mentioned in
    2 Post(s)
    Quoted
    0 Post(s)
    You'll get a slight dribble when you first open the nipple, but not a great gush.

    But the idea is to force the fluid down the hose into the jar, rather than back up the system towards the master cylinder, as you wind the piston back - this will happen anyway as the it's the path of least resistance. Just open the nipple as you start winding and close it as soon as you've done.

    That's why the tube is needed to stop air getting sucked back into the caliper.

    As for the bleeding method - it's not really changed since hydraulic brakes were invented, but using a one-man kit like Gunson's Ezeebleed makes it a doddle.

    But you need to bleed them in the following order...

    Left rear
    right rear
    Left front
    Right front

  8. #8
    Status
    Offline
    KevT.'s Avatar
    Yorkshire RO
    Join Date
    Jul 2005
    Location
    Bradford
    Posts
    9,218
    Mentioned in
    7 Post(s)
    Quoted
    15 Post(s)
    ok thanx for the info mate i will have a go tomorrow and hope that i dont need to bleed the system will let know what happens well if my dad aint killed me if it goes wrong!

    AOC top 15 car at PVS 2009 & 2010
    313.7bhp/343Ibft


  9. #9
    Status
    Offline
    KevT.'s Avatar
    Yorkshire RO
    Join Date
    Jul 2005
    Location
    Bradford
    Posts
    9,218
    Mentioned in
    7 Post(s)
    Quoted
    15 Post(s)
    hi people just to let you know the disks and pad went well it took just over an hour and that is with tiding up after which i dont normaly do

    Thank you for all your help

    AOC top 15 car at PVS 2009 & 2010
    313.7bhp/343Ibft


  10. #10
    Status
    Offline
    Ffoeg's Avatar
    2170:01:06
    Join Date
    Jun 2003
    Posts
    34,591
    Mentioned in
    2 Post(s)
    Quoted
    0 Post(s)
    Glad you got it sorted and that everyone's still alive

Page 1 of 2 12 LastLast

Similar Threads

  1. Caliper piston rewind help!
    By Dan. in forum Chassis
    Replies: 4
    Last Post: 27-03-2013, 23:21
  2. rear caliper piston
    By astrasximan in forum Astra Discussion & Chat
    Replies: 18
    Last Post: 29-04-2012, 23:15
  3. caliper piston dust cover
    By mark_mr_x_ in forum Bodywork and Exterior
    Replies: 1
    Last Post: 30-11-2004, 19:11

Posting Permissions

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