Brake booster almost stalls '86 1.8 dual carb... Normal???

Discussion in 'General Motoring' started by Cory Dunkle, Oct 20, 2003.

  1. Cory Dunkle

    Cory Dunkle Guest

    I have an '86 Prelude with a 1.8 liter dual carb engine. When I press the
    brake pedal hard the engine RPM drops a bit then stabalizes. When releasing
    the brake pedal after pressing it hard/far the RPM drops to about 100-200
    and the engine almost stalls. Is this normal? I know the engine is tiny, but
    I would thnk Honda wouldn't make a brake booster so big that when vacuum is
    applied it leans out the mixture to the point that the engine almsot stalls.
    Perhaps there is a vacuum leak somewhere in the booster or lines connecting
    to it? Any thoughts/ideas? Thanks.

    Cory Dunkle, Oct 20, 2003
  2. You probably have a leak which is most likely in the booster.


    Grumpy au Contraire, Oct 21, 2003
  3. Try this test for the brake booster, it may help you.
    Start engine with the brake pedal depressed. If the pedal sinks
    slighty, the booster is working. If pedal height does not change,
    booster or check valve is faulty.
    Or, Depress the brake pedal w/ engine running, then stop the engine.
    Hold pedal down for 30 seconds. If pedal height does not change, the
    booster is OK. If the pedal rises, booster is faulty.
    Or, With engine off, depress the brake pedal several times. As you push
    the pedal the height of the pedal should rise. If it doesn't, the
    check valve may be faulty.
    Check valve test: Disconnect the vacume hose that runs from engine to
    the booster where it connects to booster. Start the engine. If you do
    not feel any vacuum, check valve is faulty. The valve is located in
    the vacuume hose you disconneted.
    I hope this helps. Unfortunatly, I do not know if you have a bad
    booster, that it will cause the problems you are having. Good Luck.
    William Burke, Oct 25, 2003
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.