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  1. #1

    Default What Brake System Do I Have? '89

    Looking on the Autozone site for calipers since the two bleeder screws are pretty rusted / fused into the caliper I am given a JB7, JD7 or a JB5, JD5 system. Any idea on how I can find out which system I have? Thanks

  2. #2
    Master Mechanic BurbanMan's Avatar
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    Quote Originally Posted by Fine Burban View Post
    Looking on the Autozone site for calipers since the two bleeder screws are pretty rusted / fused into the caliper I am given a JB7, JD7 or a JB5, JD5 system. Any idea on how I can find out which system I have? Thanks
    I don't remember how to tell, but You went to the wrong parts house for brake parts. Unless you want to change them again in 6mo. Get them from napa. You'll pay a little more, but they last.
    Chuckie!!!


  3. #3

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    In GM vehicles, those 3 digit alphanumeric codes are called RPO (Regular Production Option) codes. There should be a list glued to the inside of the glovebox with the RPO codes for the options that were factory installed in your vehicle.
    '98 K1500 Suburban LS 5.7 L 4L60E NV246 ARB
    '92 Ford Explorer XLT 4x4 4.0 L A4LD BW13-54 Trac-loc rear
    "My toys were the greasy cogs and springs and pistons that lay around all over the place, and these, I can promise you, were far more fun to play with than most of the plastic rubbish children are given nowadays." Danny in Roald Dahl's Danny The Champion of the World

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  5. #4

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    Is there a source to get copies? The one in my '94 Suburban is faded beyond reading.

  6. #5

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    Like Shorty asked, is there any other way to get a copy OR can you figure it via VIN? Thanks for that info though.

  7. #6

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    In short, the RPO codes for brakes correspond to whether the brake system is vacuum-boosted or hydroboosted, and what the GVWR of the vehicle is. So, if you can't read your RPO sticker anymore, but the sticker in your doorjamb that has all the weight ratings is, you can figure it out from there. Here's the list of brake systems with a vacuum booster:

    JB5 BRAKE POWER, DISC/DRUM, 6,400 LBS
    JB6 BRAKE POWER, DISC/DRUM, 7,200 LBS
    JB7 BRAKE POWER, DISC/DRUM, 8,400 LBS
    JB8 BRAKE POWER, DISC/DRUM, 10,000 LBS

    Similarly, here's the list of brake systems that used the hydroboost:

    JD5 BRAKE DUAL POWER, DISC/DRUM, 6,400 LBS
    JD6 BRAKE HYD POWER, DISC/DRUM, 7,200 LBS
    JD7 BRAKE HYD POWER, DISC/DRUM, 8,400 LBS

    Keep in mind that the weight ratings in the RPO codes reflect the GVWR and not the GAWR, GCWR, or any other rating. I hope this helps.
    Christopher

    1991 Chevy Suburban 1/2 ton 2WD w/ chevy SBC 350-3/4 ton drivetrain upgrade w/4.10 gears 200K miles
    2005 Saturn ION-2 Stock 265K miles
    1982 Bronco, 1993 Bronco (sold), 1971 M35A2 Deuce and a Half



    There are 10 kinds of people, those who understand binary, and those who dont...

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  9. #7

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    Is there a source to get copies? The one in my '94 Suburban is faded beyond reading.
    I believe that GM, either through dealerships or through some other customer service source can look up the original RPO codes if you give them your VIN #. The one thing I would worry about is how far back they maintain those records -- 10 model years? 20 model years? I don't know.
    '98 K1500 Suburban LS 5.7 L 4L60E NV246 ARB
    '92 Ford Explorer XLT 4x4 4.0 L A4LD BW13-54 Trac-loc rear
    "My toys were the greasy cogs and springs and pistons that lay around all over the place, and these, I can promise you, were far more fun to play with than most of the plastic rubbish children are given nowadays." Danny in Roald Dahl's Danny The Champion of the World

  10. #8

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    Quote Originally Posted by MrShorty View Post
    I believe that GM, either through dealerships or through some other customer service source can look up the original RPO codes if you give them your VIN #. The one thing I would worry about is how far back they maintain those records -- 10 model years? 20 model years? I don't know.
    They keep it for about 10-15 model years depending on vehicle type. For the trucks its only 10 because of the large volume that are built. I learned this talking to a GM rep who tried to find information on my truck but said that its too old to retrieve info on.

    1996 Chevy Tahoe LT 5.7L V8 4X4 205,000+ miles. Built proudly at Janesville Assembly in Janesville, Wisconsin
    Basic mods: Lights all over, bunch of electrical work, and a couple cooling mods.

    Check out my other mods in My Garage: http://www.gmtruckclub.com/forum/sho...t-Tahoe-4-Door

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