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brake booster

Discussion in '40- & 55-Series Tech' started by bad_religion_au, Aug 7, 2003.

  1. bad_religion_au

    bad_religion_au

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    since i've redone my hj45 brakes, i've noticed that my pedal on the 76 fj40 is solid as :eek: without the retardation you'd expect for the force put in. i also notice the pedal drop i notice on the hj at startup is absent from the fj, is this a booster problem. how do i trouble shoot this. could it just be lack of vacume, or a shot booster, or am i out of my tree?
     
  2. s79bj40

    s79bj40

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    yes its a booster problem, your missing vacuum at some point. The petrol doesn't have the same vacuum pump as the hj, so just check all the pipes going in and out of the booster and the vacuum tank. But to sort it properly, you will have to have a good play with some light pressure to find where the problem really is.

    sam
     
  3. bad_religion_au

    bad_religion_au

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    how much vacum are we talking about here. if i was to say, remove the vacume hose from the booster and put my finger over the end to test if the hose has vacume pressure, would i expect to get the skin removed from my finger tip?
     
  4. woody

    woody Internet Fireman Staff Member

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    the vacuum is direct from the manifold, should be in the 16" range...get a vacuum gauge, $10 and worth it.

    you'll keep the skin, but you won't have to worry about blackheads...hehehe
     
  5. bad_religion_au

    bad_religion_au

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    i suspect it is the booster itself. which means finding somewhere to repair/ replace, if my Hj (actually technically my little bro's) is back on the road after this inspection, the Fj is having a holiday.

    i read that vacuum leaks can result in valve damage. is this true?
     
  6. woody

    woody Internet Fireman Staff Member

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    [quote author=bad_religion_au link=board=1;threadid=4167;start=0#msg31018 date=1060348326]
    i read that vacuum leaks can result in valve damage. is this true?
    [/quote]

    yes...it can burn up valves on #5/#6...definitely a bad thing.