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Thread: major vacuum leak

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    Default major vacuum leak

    My R/T has a vacuum leak. It's so bad that it throws a P0420 code. After a few minutes the brake pedal is hard as a rock. I've checked the easy places but I'm not familiar with where everything else is. I found the small shiny diaphragm next to the heater lower vent. Can anybody help? Thanks Ray

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    Hugh Jassole's Avatar
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    sounds like your brake booster might be going bad
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    yep That's a leaky booster, try rockauto Ray or local parts house not extremely hard to replace just a few nuts a clip and pin in pedal hardest thing will be working under the dashboard


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    got mine from rockauto the other month was half the price compared to advanveauto and other auto parts stores. check your master cylinder for leaks too. thats what usually causes the brake booster to fail. or it did for me atleast.
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    Thanks for the info guys. I'll check into the brake booster & the master cylinder.

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    I checked out the master cylinder. No leaks, under the hood or under the dash. I know this because I haven't added any brake fluid since I drained & refilled the system. I found the four nuts that hold the booster to the firewall. I was told that there are also some clips, but I don't know where they are or how to remove them. Any help will be appreciated. Ray

  7. #7

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    Quote Originally Posted by rayhandloser View Post
    I checked out the master cylinder. No leaks, under the hood or under the dash. I know this because I haven't added any brake fluid since I drained & refilled the system. I found the four nuts that hold the booster to the firewall. I was told that there are also some clips, but I don't know where they are or how to remove them. Any help will be appreciated. Ray
    Need to look over the brake pedal Ray; see how it attaches to the rod & the brake lite switch is there also...


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    Thanks. I'll look & even take a photo or two. Bad news....Chrysler no longer makes or has made brake boosters for 1998 Dakotas. So its off to NAPA in the morning. Ray

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