Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Brakes went to the floor (hydroboost)

Discussion in 'The Garage' started by mountainexplorer, Dec 6, 2005.

  1. mountainexplorer

    mountainexplorer 1/2 ton status

    Joined:
    Nov 14, 2001
    Posts:
    4,903
    Likes Received:
    0
    Location:
    Spokane, Wa./Ione, Wa
    I was just thinking about how good the brakes on my diesel were. The next day, they pretty much went to the floor. It has hydroboost, and the PS pump is fine, and it's not leaking fluid anywhere from any lines or seals.

    Anything different on a hydroboost system as far as why the pedal would start going to the floor? If I pump it, it seems to pump up and work up higher. Maybe it's just the master cylinder.
     
  2. mudjunkie 82

    mudjunkie 82 1 ton status GMOTM Winner

    Joined:
    Dec 27, 2002
    Posts:
    11,449
    Likes Received:
    0
    Location:
    Cleveland Ohio
    sounds like air in the system.
     
  3. darenofears

    darenofears Registered Member

    Joined:
    Jan 25, 2005
    Posts:
    47
    Likes Received:
    0
    Location:
    Indiana
    bleed mastercylinder and brakes
     
  4. mountainexplorer

    mountainexplorer 1/2 ton status

    Joined:
    Nov 14, 2001
    Posts:
    4,903
    Likes Received:
    0
    Location:
    Spokane, Wa./Ione, Wa
    Strange though how they've worked perfect since I've had the truck, and all of a sudden they get air in the lines?
     
  5. K10bolts

    K10bolts Registered Member

    Joined:
    Feb 8, 2005
    Posts:
    35
    Likes Received:
    0
    Location:
    Big Rapids, Michigan
    To test the master cylinder for an internal leak, pump up the brakes until the pedal is hard and hold. Let up a small amount while still holding pressure and watch to see if the pedal sinks.
     
  6. mouse

    mouse 1/2 ton status

    Joined:
    Nov 10, 2003
    Posts:
    1,448
    Likes Received:
    0
    Location:
    Great Falls Mt
    My bet is that you had a seal go bad in the master cylinder. I've seen it dozens of times on vac-boost cars. The master cylinder here works the same way.
     
  7. DieselDan

    DieselDan 1/2 ton status

    Joined:
    Jan 27, 2001
    Posts:
    1,056
    Likes Received:
    0
    Location:
    Vermont
    Ya, the problem is not in your hydraboost it's your mastercylinder.

    I've seen hydraboost units not work at all = hard push pedal (actual failure was the power steering pump) or the hydrabooster was actually applying/dragging the brakes :eek1:

    Kinda surprising that you lost both halfs of your master though. Was your pedal a little low? Most of your braking force comes of the front brakes. Unless you brake pretty hard you might never realize the rears are inop. The warning light and/or lower pedal height is your only clue. I did loose a brake line right close to a master once; it sucked air back into the master and neither side (dual diagonal master cylinder) worked in about three pedal pushes :eek:
     
  8. mouse

    mouse 1/2 ton status

    Joined:
    Nov 10, 2003
    Posts:
    1,448
    Likes Received:
    0
    Location:
    Great Falls Mt
    Chrysler product? I've worked on a few of those...
     
  9. kgblazerfive

    kgblazerfive keymaster Premium Member GMOTM Winner

    Joined:
    Dec 2, 2004
    Posts:
    10,620
    Likes Received:
    610
    Location:
    Hooper, Utah 84315
    Mine is doing the same thing when its cold or the first time I push on the brakes, which is always when I need them the most. I also just replaced my Hydro-boost
     
  10. DieselDan

    DieselDan 1/2 ton status

    Joined:
    Jan 27, 2001
    Posts:
    1,056
    Likes Received:
    0
    Location:
    Vermont
    Nope, VW. The kicker is the brake line was worn thru. Seems every time I put the car in reverse the linkage rubbed one of the lines. After ten years of this..... :doah:
     

Share This Page