Author Topic: JL-8 Question  (Read 6848 times)

ZLP955

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JL-8 Question
« on: August 27, 2015, 09:43:04 AM »
If a car was optioned with JL-8 from the factory, but is now missing both the complete rear axle and the front brake calipers, is there anything about the various brake line brackets attached to the body that would still identify JL-8 as opposed to just power front discs?
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA.
AHRA Formula Stock at Lions Dragstrip, NHRA E/MP at Pomona Raceway

WorkinProgress

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Re: JL-8 Question
« Reply #1 on: August 27, 2015, 12:10:13 PM »
JL8 cars use front brake hose brackets that are the same on drum brake cars.

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KurtS

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Re: JL-8 Question
« Reply #2 on: August 27, 2015, 09:28:14 PM »
Nice!
That's why we keep Warren around. :)
Kurt S
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Bryan302

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Re: JL-8 Question
« Reply #3 on: August 28, 2015, 04:28:44 AM »
Tim,  Are ALL of the front brake components gone?  You mentioned just the calipers.  If the AB coded hub/spindles are there, they should be noticeably different, including the caliper mounting bracket, hub, steering arm, CX coded brake cyl., etc.  Some good reference photos are in John Hooper's book, page 121.  Hope you find a clue!

Bryan
Bryan S.
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1969 Z/28 X33, 05A, PNT 52 52, TR 719, endura bumper

ZLP955

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Re: JL-8 Question
« Reply #4 on: August 29, 2015, 09:56:50 AM »
In the original question, I was primarily thinking of the brackets on the rear body, and only made the comment about the missing front calipers because the car was drag raced at some point and whatever it left the factory with has long gone, replaced with front drums.
It sounds like the only way to ID it as it sits (missing those obvious parts) is by it being a model that would've been a mandatory J52 car, yet it having drum brake type front line brackets; in this case, even if it has them, no way to be certain the subframe is original to that vehicle and not from a donor base car.......therefore not really worth going back to the car to check.
Thanks everyone for your replies.
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA.
AHRA Formula Stock at Lions Dragstrip, NHRA E/MP at Pomona Raceway

JL8Jeff

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Re: JL-8 Question
« Reply #5 on: August 29, 2015, 02:39:51 PM »
If it originally had power disc brakes, the JL8 would not have the proportioning valve like the regular J52 would.  If it was originally drum brakes it would have a different master cylinder compared to the disc brakes.  If all the brake stuff was switched out for racing then it would be pretty tough to know for sure.  Does it have the disc brake brake pedal?
1969 Z28 JL8 4 wheel disc brakes, #'s match - being restored

firstgenaddict

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Re: JL-8 Question
« Reply #6 on: September 20, 2015, 03:09:42 AM »
JL8's don't have the holes(if they are there) in the upper a-arms threaded , the bolts are self tapping.
James
Collectin' Camaro's since "Only Rednecks drove them"
Current caretaker of 1971 LT1's - 11130 and 21783 Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
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ZLP955

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Re: JL-8 Question
« Reply #7 on: September 20, 2015, 09:58:57 AM »
Jeff, sorry I missed your question at the end of your reply when I originally read it. Yes, the car has the bright disc brake center to the brake pedal.
James, when I looked at the car the upper A-arms did have the holes on the trailing edge. Didn't take notice of them being threaded or not. Are you saying that if the holes are there, and have no thread, JL8 could still be a possibility, but if the holes have a thread, then not possible, it's a J52-equipped model?
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA.
AHRA Formula Stock at Lions Dragstrip, NHRA E/MP at Pomona Raceway

WorkinProgress

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Re: JL-8 Question
« Reply #8 on: September 20, 2015, 04:22:32 PM »
JL8 built cars have no holes in the upper A arm for brake hose retainer clip that is used on standard 11" front disc brakes . JL8 built cars use upper A arms that are the same as front drum brake cars.

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firstgenaddict

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Re: JL-8 Question
« Reply #9 on: September 20, 2015, 09:58:02 PM »
JL8 built cars have no holes in the upper A arm for brake hose retainer clip that is used on standard 11" front disc brakes . JL8 built cars use upper A arms that are the same as front drum brake cars.

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That's what I did not know... THANKS WARREN!!!   
in this case the holes in the subframe where the brackets would have been should have no threads, because the bolt cut the threads there as well..
James
Collectin' Camaro's since "Only Rednecks drove them"
Current caretaker of 1971 LT1's - 11130 and 21783 Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

WorkinProgress

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Re: JL-8 Question
« Reply #10 on: September 21, 2015, 12:46:08 AM »
Since I am not sure which brackets disc or drum you are referring to I will explain it both ways.

If you have a front drum brake car or JL8, it uses the same configuration meaning no holes in the side of upper A arm for brake hose retaining clip. Brake hose brackets will be on the outer side of each frame rail, and the pass top frame hole where a standard front 11" disc brake hose bracket would go will not be threaded.

If you have standard front 11" disc rotors the outer frame rails where the drum brake hose brackets go will not be threaded and the upper A arms should have two holes on the side for the brake hose retaining clip.

Also, some early built '69 Nova, and '69 Camaro front drum brake hose frame brackets are stamped JL8. In case someone sees them on a car does not mean it is a JL8 built car. All the original JL8 cars I have seen do not have JL8 stamped into the front brake hose brackets.

Hope I covered the brackets, threaded and unthreaded holes you were referring to......Warren

ZLP955

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Re: JL-8 Question
« Reply #11 on: September 21, 2015, 09:18:09 AM »
Thanks for a great explanation Warren, that couldn't be clearer.
So based on the brackets and holes I saw in the frame and upper A-arms, the subframe is from a front disc brake only car. There's doubt in my mind that the sub is original to the car it's in, so I think there is no way to know. I'll save myself a 20-hour round trip going back to check further :D
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA.
AHRA Formula Stock at Lions Dragstrip, NHRA E/MP at Pomona Raceway