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  1. #1
    Member JimBobC4's Avatar
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    Corvette(s)
    1995 Dark Red 6spd Convertible

    Default J55 Heavy Duty Brakes ?

    I have been researching the RPO codes for my 1995 convertable and have found my car has the

    J55Heavy Duty Brakes

    among a host of other high performance RPO codes. (3:45 6spd, etc )

    I have the front tires off and it looks like standard vette equipment to me.

    I have done a search on this site and a few others and have found conflicting information concerning the J55 option.

    What is it exactly ? Bigger rotors ? or different valving ? just a gimmick ?

    Any ideas ?
    Jimbobc4

  2. #2
    jrp
    Member jrp's Avatar
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    Polo Green LT4

    Default

    J55 is pretty much 13" rotors and the calipers/hardware to accommodate them. They became standard equipment in '95 or '96, but 12" rotors were standard before then.

    Other than that, appearances are quite similar.

  3. #3
    Member JimBobC4's Avatar
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    Corvette(s)
    1995 Dark Red 6spd Convertible

    Default

    Ok, after way too much research and in talking to the Autozone guy,
    the J55 option was actually for bigger brakes. 13 inch rotor as opposed to 12 inches. The rotors are unidirectional as well so a left and right side exist.
    Also the calipers are different.


    or ...


    what he said above it became standard on a 1996 model.

  4. #4
    Tuna's Avatar
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    '13 427 60th

    Default

    Corvette Black Book notes that the J55 "big brake" option became standard on all Corvettes in 1995.
    In 95 and 96, some Corvettes (Pace Car, ZR1, GS, Collectors Edition) got different calipers; but, the 'big' 13 inch rotors were standard and the capacity of the brakes were basically the same for all.
    Tuna
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  5. #5
    Moderator Toms01's Avatar
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    Corvette(s)
    2001 Magnetic Red Coupe

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    J55 was an option up to 1995 when the 13" front brakes became standard. I know that the Z07's (1991-1994) got the "big brakes" as part of the option package. Before then I'm not sure, maybe the Z51 equipped cars got them.

  6. #6
    Member JimBobC4's Avatar
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    Corvette(s)
    1995 Dark Red 6spd Convertible

    Default

    Quote Originally Posted by Tuna View Post
    Corvette Black Book notes that the J55 "big brake" option became standard on all Corvettes in 1995.
    In 95 and 96, some Corvettes (Pace Car, ZR1, GS, Collectors Edition) got different calipers; but, the 'big' 13 inch rotors were standard and the capacity of the brakes were basically the same for all.
    If the 13's are standard why are they listed as an RPO option ($$$) on my 1995 ?

    www.autozone.com had both JLE1 and J55 listed for 1995. Only J55 type for 1996.

    www.advancedautoparts.com also has two different rotors listed for 1995 as well.

    Also, Raybestos has two different rotors listed as well
    Raybestos Aimco-GS Brake Rotor Brake Rotor: Aimco-GS; Front; 12" Rotor Diameter; Except Heavy Duty Power Brakes; 2 Per Car 1995 Corvette Front

    Vehicle: 1995 CHEVROLET CORVETTEEngine: V8 5.7 Liter FIBrake Rotor: PG Plus; Front; Right; Heavy Duty Power Brakes; 13" Rotor Diameter; 1 Per Car

  7. #7
    Tuna's Avatar
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    GM uses the RPO codes to describe what components are on the car even if that particular RPO is standard. J55 is standard in '95 and '96 and J55 is listed on all '95 and '96 RPO code stickers. The cost of J55 was included in the base price of the 95/96 cars.

    Prior to that, J55 was not a stand-alone option so you could not order a standard car with the big brakes - J55 came with Z07 or ZR1.

    If autozone, Advanced, etc., want to list other brake options, that needs to be taken up with them.

    If you want to question the parts catalogs, even MidAmerica shows the 12" brake rotors as fitting 88-96 and that is obviously incorrect.

    Your '95 should have 13" rotors and the associated J55 components.
    Tuna
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  8. #8
    Member JimBobC4's Avatar
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    Corvette(s)
    1995 Dark Red 6spd Convertible

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    Interesting ! Thank you. I trust the forum and the black book more than Autozone .


    Thanks for the clarification.

  9. #9
    Member 85dougnash's Avatar
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    Corvette(s)
    1985 Doug Nash Coupe

    Default No J's

    Damn. I got no J's on my RPO sticker.

    Foy
    (no J's) in Las Vegas

  10. #10
    Tuna's Avatar
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    Quote Originally Posted by 85dougnash View Post
    Damn. I got no J's on my RPO sticker.

    Foy
    (no J's) in Las Vegas
    '85 came with 16" wheels so the 12" brakes were already as big as they got. The "big brake" package came with the introduction of 17" wheels in 1988.

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