Results 1 to 5 of 5

Thread: Brake MC - One way valve?

  1. #1
    Senior Member
    Join Date
    Jun 2009
    Name
    Alex
    State
    NSW
    Location
    Ryde
    Country
    Australia
    Posts
    144

    Default Brake MC - One way valve?

    Yo.

    Brake question.

    I've got a 1984 AE71. Bigport 4AGE, with silvertop quads and an adaptronic.

    Problem being is that i was just about to finish setting up my balance bar / vacuum manifold the other day, and was at Supercheap sourcing some bog standard vac hose, the same type i'd been using to run from each quad, fuel pressure regulator, map sensor etc... and the bloke at supercheap happened to ask what i was doing.

    I replied with, Oh, just finishing up a vacuum manifold, and i need a bigger diameter vac hose to run from the bigger nipple on the brake master cylinder to the vac manifold.

    He was like, "OH NO YOU CANT DO THAT! WHATS WRONG WITH YOU??!?!?
    The hose that runs from the stock car has a special one way valve in it, so that you don't lose pressure to your brakes when you're on throttle. You can't just use a standard bit of hose! What do you think'll happen when you jump on the throttle without a valve? No brakes!"

    Now to my mind, i've never heard of this theory. And the dude's name was Frank. An untrustworthy name, i've seen 'Catch Me If You Can'. But it does make some sense to regulate pressure. Although on inspection of my standard brake MC hose, i could blow air both ways through the length of pipe, and i couldn't feel and kind of bulges or sections that might give away the location of a valve. And i thought that to my mind, i wouldn't put a valve in a piece of pipe, i'd put in the actual brake MC. But just thought i'd check.

    Is he right? Is there a valve in brake MC hose?

    Or can i use a piece bog standard, no valve vac tubing with no worries?

    Thanks kids.
    http://img32.imageshack.us/img32/7938/therust.jpg

  2. #2
    Senior Member
    Join Date
    Jan 2009
    Name
    Mark
    State
    TAS
    Location
    Hobart
    Country
    Australia
    Posts
    783

    Default

    there is a one way valve in the hose from your vacuum source to you BRAKE BOOSTER. There should only be brake lines going into your master cylinder.
    With out the valve you with have no vacuum assist for your brakes. They'll work but you'll need to push them pretty hard.
    Unless you've changed the brake booster you should be able to use the original hose with the valve in it. If the hose bends the wrong way you can use the same size hose and just put the original valve in that line.
    Launceston = Home of the surprise sodomist!!

  3. #3
    Senior Member
    Join Date
    Jun 2009
    Name
    Alex
    State
    NSW
    Location
    Ryde
    Country
    Australia
    Posts
    144

    Default

    Apologies, why i said MC is anyone's guess.

    So there is truth to the theory? Wow, my money was on him being wrong.

    But where exactly is the valve? I felt all up and down the length of it and couldn't feel any telltale signs of something being inside the hose. And if there is a valve, why could i blow both ways through my original length of hose?
    http://img32.imageshack.us/img32/7938/therust.jpg

  4. #4
    Senior Member H8CHIR6KU's Avatar
    Join Date
    Dec 2008
    Name
    Aaron
    State
    WA
    Location
    Perth
    Country
    Australia
    Posts
    987

    Default

    you wont find the valve in the hose cause there isnt one, its external to the hose. on your standard booster just after a little bit of hose there is a little plastic thingy with an arrow on it. it should be bolted to your firewall. that is your valve. it plugs into the hose between manifold and booster

  5. #5
    Senior Member H8CHIR6KU's Avatar
    Join Date
    Dec 2008
    Name
    Aaron
    State
    WA
    Location
    Perth
    Country
    Australia
    Posts
    987

    Default

    just for you


Similar Threads

  1. Blocked brake proportional valve
    By BARWICK in forum Technical - Questions
    Replies: 2
    Last Post: 25th October 2011, 06:53 PM
  2. BRake Lines - Brake Booster One-Way valve
    By bigm in forum Cars or Parts Wanted
    Replies: 2
    Last Post: 29th January 2010, 06:56 AM
  3. Do I need to use my brake balance adjuster valve thingy yet?
    By Beck in forum Technical - Questions
    Replies: 10
    Last Post: 4th May 2009, 12:11 PM
  4. jdm brake proportion valve
    By quoccy in forum Cars or Parts Wanted
    Replies: 3
    Last Post: 22nd October 2007, 06:43 PM

Posting Permissions

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