Brake issues
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Brake issues
Hey guys. I've got an 84 F100 4.9 manual. I was driving to work this morning and my brakes started giving me issues. It took a long time to stop and the pedal lost its firmness and it hissed when I press it down. I'm guessing it's my brake booster? I've still got plenty of fluid and I haven't been losing any. Anything I can do to narrow down the problem? Thanks!
More Turbo
Joined: Oct 2009
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From: Jonesborough, TN
It could be the booster. If pushing the pedal harder when stopped, elicits a hiss than that would be my guess. Failure of the master cylinder gives a soft, spongy pedal with no hissing. Eventually, it will just fail. You will have to disconnect the master cylinder to replace the booster, although you don't have to remove brake lines, so you won't need to rebleed the system when done. Personally, though, if you haven't replaced the master cylinder lately, you might want to replace both.
Good luck.
Good luck.
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Joined: Jan 2012
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From: Richmond
I'm of the school of thought to do both. From my own experience and seeing it on other cars a lot of times a master cylinder will leak back out into the inside of the booster, killing it. First time I lost brakes on a car I got a pair of pants ruined from brake fluid pouring onto my right foot haha.
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I ended up replacing both. Once I pulled them off it was pretty obvious they were both in need of replacing. The only thing is, I'm still having an issue with the booster killing the engine. I wrapped up the whole process, bled the brakes and everything felt good. I drove it around the block and it was fine, but then after I tried adjusting the pressure switch (which didn't turn off my dash brake light) I couldn't get out of my drive way without killing the engine. The booster was remanufactured...so could it still be bad? Or am I having a vacuum issue somewhere else?
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So, you stepped real hard on the brake pedal, right? I think that's how one resets that switch but it's been a while.
Please be clear, it helps people help you. Give exact descriptions telling us exactly what you did and how the engine reacted, what have you done to diagnose it, when the problem began and what you changed that may (or may not) have caused it.
Nobody here is going to be able to look into a crystal ball and help you based only on a description of killing the engine getting out of the driveway, that is WAY too vague.
BTW I don't generally consider "resetting" and "adjusting" the same thing.
Please be clear, it helps people help you. Give exact descriptions telling us exactly what you did and how the engine reacted, what have you done to diagnose it, when the problem began and what you changed that may (or may not) have caused it.
Nobody here is going to be able to look into a crystal ball and help you based only on a description of killing the engine getting out of the driveway, that is WAY too vague.
BTW I don't generally consider "resetting" and "adjusting" the same thing.
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That's the opposite of how you reset it. You open a line on the master cylinder and gently press until the light goes off. And if that doesn't work you open the other line and try again. Mine didn't reset either way so I'm assuming it needs to be replaced. I'm less concerned about that. I'm wondering why my engine dies at random. I replaced the booster and the master cylinder. That's it. When I put my truck in gear and try to drive all the air gets sucked out and the engine dies. I'd love to be more specific but I don't get why its happening.
It seems like you like trolling people on here more than helping.
It seems like you like trolling people on here more than helping.
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Joined: Jul 2010
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From: Northeast, OK
That's the opposite of how you reset it. You open a line on the master cylinder and gently press until the light goes off. And if that doesn't work you open the other line and try again. Mine didn't reset either way so I'm assuming it needs to be replaced. I'm less concerned about that. I'm wondering why my engine dies at random. I replaced the booster and the master cylinder. That's it. When I put my truck in gear and try to drive all the air gets sucked out and the engine dies. I'd love to be more specific but I don't get why its happening.
It seems like you like trolling people on here more than helping.
It seems like you like trolling people on here more than helping.
If you don't care to be accurate or are offended if people ask you to document what you are saying then maybe this isn't the place for you. On the other hand, if you truly want help and don't make bold statements that you can't back up then we have time for you. Your call.
More Turbo
Joined: Oct 2009
Posts: 731
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From: Jonesborough, TN
Hey ATXF100,
Chris (ctubutis) and Gary are two of the most helpful guys, among many, on this list. Specifics are necessary to narrow down the problem. That's all they, and most of us, ask. Without specifics, it sounds like a vacuum problem, like Chris eluded to. Wow, that narrows it down to the engine compartment. See what I mean. But as Chris said, I would unplug and cap the brake booster vacuum hose, and try driving it, carefully, and if it doesn't die, then you've narrowed your problem down to the booster. Good Luck.
Chris (ctubutis) and Gary are two of the most helpful guys, among many, on this list. Specifics are necessary to narrow down the problem. That's all they, and most of us, ask. Without specifics, it sounds like a vacuum problem, like Chris eluded to. Wow, that narrows it down to the engine compartment. See what I mean. But as Chris said, I would unplug and cap the brake booster vacuum hose, and try driving it, carefully, and if it doesn't die, then you've narrowed your problem down to the booster. Good Luck.