CRG Discussion Forum
Camaro Research Group Discussion => Decoding/Numbers => Topic started by: 67 BB on November 01, 2011, 11:28:21 PM
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Is the J56 metallic disk brake front end w/ rear metallic drum brakes a z28 option only or could bigblock cars also in 67 order this option? thx
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It is Z28 only.
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thx
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Here it is with more info:
http://www.camaros.org/suspen.shtml#Brakes
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You could only get J65 all metal drums front/rear if you had a ss or J52 disc brake non metal w/ non metal posi. But a z28 could get J56 metal disk and metal rear. Interesting...
Could you combine 2 Rpo's and order J65 and J52 and have non metal disks and a metal drum rear as a result? thx
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J56 was a heavy duty brake package available only on the Z28 in '67 and while that included metallic lining for the rear drums it did not include metallic brake pads for the front calipers. What was special about the J56 front calipers was the fact that they had heat insulators on the brake pistons. This kept the brake fluid from boiling under extreme braking conditions such as those experienced in Trans-Am road racing.
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So they weren't a dual pin like the J56 Vette components?
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The RPO J56 caliper as used on 205 of the 602 Z-28s built in '67 was a single pin design and externally looked no different than any other 4-piston disc brake caliper used on a '67 production line Camaro. When you removed the disc brake pads, then you could observe the heat insulators on the brake pistons. With that being said, there was an over-the-counter service part available that was a heavier duty verison of this caliper. It had the same heat insulators but the boss for the single pin was machined off and the opening for the disc brake pads was enlarged to accept the twin-pin metallic brake pads used for Corvette racing applications (also denoted as J56). The inner and outer casting halves of the Camaro caliper were drilled to accept the two cotter pins which located these Corvette pads in the Camaro caliper. Extremely rare pieces.
As noted in the '68 Z/28 brochure and a few other places, these are for the 11" rotors (J52 disc/drum), not the 4-wheel disc brake 11.75" rotors.
P/N 5468886 Caliper Assy, Front Disc Brake L.H. (special design)
P/N 5468887 Caliper Assy, Front Disc Brake R.H. (special design)
P/N 5468882 Pads, Caliper (for above) (special material)
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So if I take my calipers off and pull the pads I can check out the pistons but what does the insulators look like ? Do you have a pic. thx. I was just curious why big blocks couldn't order the option if they expected to drag race them and would also undergo heavy braking.
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Attached are two photos, one showing the standard J52 disc brake caliper and the other shows what a heat insulator and piston from a J56 disc brake caliper looks like (but with some damage from being over 40 years old). What you would see in an assembled caliper is the face of the black insulator with the phillips head screw in the middle.
I can't answer why it was only available on the Z. Maybe they were so limited because the supplier could only guarantee the availability of "X" amount of pieces.
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Jon,
Didn't your mountain green car have J56?
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Yes, it is a documented J56 car.
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John,
Thanks for clarifying the J56 option . When I was doing my 67 Z I asked about the insulators when I had the calipers rebuilt. Lone Star said that they had never seen a Camaro caliper with the insulators and wanted to know if I wanted them put back on. Good move at the time. Now I know that they are correct for my car a it is an original J56 car. Thanks again. Bill
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Bill,
I remember hearing that story about your calipers, probably from Jerry. When Fred Hucke and I had J56 calipers done by Lonestar about a year ago they recounted that they had only seen 1 set of these before and I immediately knew whose calipers they were talking about.