Author Topic: Disc brake proportioning valve  (Read 3108 times)

Terry69RSZ28

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Disc brake proportioning valve
« on: November 03, 2016, 03:39:06 AM »
Hi Everyone,
Do 69 disc brake proportioning valves have any numbers or date codes on them?
Thanks for your expertise, Terry

69Z28-RS

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Re: Disc brake proportioning valve
« Reply #1 on: November 03, 2016, 04:06:57 AM »
Yes, see photo...  I believe the date code is encoded as:   julian date - Yr .. (mine is '154 - 9')  for the 154th day of 1969...  Also  'K-H' for Kelsey Hayes  and an 'R' for ...??.. rear?
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

BULLITT65

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Re: Disc brake proportioning valve
« Reply #2 on: November 03, 2016, 04:59:42 AM »
great pic Gary. Now you just gave me something to want to look at next time I am in front of my own..... :D
1969 garnet red Z/28 46k mile unrestored X77
-Looking for 3192477 (front) spiral shocks 3192851 (rear)
-Looking for an original LOF soft ray windshield
-Looking for original Delco side post negative battery cable part # 6297651AV

ZLP955

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Re: Disc brake proportioning valve
« Reply #3 on: November 03, 2016, 09:23:39 AM »
Great article on brake valves right here: http://www.camaros.org/brakevalve.shtml
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

Terry69RSZ28

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Re: Disc brake proportioning valve
« Reply #4 on: November 03, 2016, 01:50:17 PM »
Thank you very much for clarifying my question!
Much appreciated, Terry

69Z28-RS

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Re: Disc brake proportioning valve
« Reply #5 on: November 03, 2016, 01:50:40 PM »
Absolutely ZLP...  JohnZ's article is great and I refer to it often myself.   (I should have remembered to refer to that in answering the OP's question)...  :)
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

jdv69z

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Re: Disc brake proportioning valve
« Reply #6 on: November 03, 2016, 08:29:05 PM »
So I have a question regarding the distribution block that turns the brake light on if there is a pressure differential between the 2 sides. Can this only occur when the brakes are applied? That is, can there be a pressure differential when the brake pedal is not being depressed? My brake light stays on whenever the distribution block wire is connected, and the ignition is on.. And I know that wire goes to ground. As if the internal spool which moves is permanently stuck somehow or touching gound?
Jimmy V.

ZLP955

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Re: Disc brake proportioning valve
« Reply #7 on: November 04, 2016, 02:49:40 AM »
Can't answer your question Jimmy, but if it turns out your switch needs a rebuild, here's a great tech procedure from Muscle Car Research: https://www.musclecarresearch.com/gm-3956727-rebuild
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

jdv69z

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Re: Disc brake proportioning valve
« Reply #8 on: November 04, 2016, 02:34:09 PM »
Thanks, I appreciate the info!!  :D
Jimmy V.

 

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