proportion valve
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Joined: Nov 2001
Posts: 143
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From: colorado springs, colorado, USA
Car: 83-84 camaro, 95 formula firehawk
Engine: 305, 305ho, 350tpi, 350 lt1, 383lt1
Transmission: 700r4, t-5, t56, m6
Axle/Gears: 3:90, 4:10, 3:50, and more
proportion valve
In my 83 z28, disk front and drum rear, somone who had the car before me tried to bleed the brakes and messed up the valve, i only have front brakes. I have talked to some people but they say i have to get a new valve, becasue you cant re-set them. This seems un-likly to me that GM would do that. Is there any way to re-set it, or do i have to buy a new one? If so, where can i get one, and also is the proporting valve from jegs (950-260-2220) leagel on a road car? or is it just for race use. Thanks in advance for the help.
Thread Starter
Member
Joined: Nov 2001
Posts: 143
Likes: 0
From: colorado springs, colorado, USA
Car: 83-84 camaro, 95 formula firehawk
Engine: 305, 305ho, 350tpi, 350 lt1, 383lt1
Transmission: 700r4, t-5, t56, m6
Axle/Gears: 3:90, 4:10, 3:50, and more
ok guys, be pals, send me some info.
Supreme Member
Joined: Mar 2000
Posts: 13,414
Likes: 6
From: Central NJ, USA
Car: 1986 Firebird
Engine: 2.8 V6
Transmission: 700R4
On a disk/drum (J50 option code) brake setup, the prop valve does have some kind of reset valve on it. It's covered up by a rubber plug. Don't ask me what to do with it, though!! 
But yeah they say that in some cases, "extreme" unbalanced brake pressure can force the internal valve to stick all the way to one side.
I'd just make sure that the rear is bled properly. If your pressure was that unbalanced, your "BRAKE" warning light should be lighting up on the dash...
You can buy a new prop valve from GM for $80 or so.
But yeah they say that in some cases, "extreme" unbalanced brake pressure can force the internal valve to stick all the way to one side.I'd just make sure that the rear is bled properly. If your pressure was that unbalanced, your "BRAKE" warning light should be lighting up on the dash...
You can buy a new prop valve from GM for $80 or so.
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Posts: 6,420
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From: Fort Mill, SC, USA
Car: '88 Iroc, '91 RS, and a '70 RS
Engine: 5.7 TPI; 5.0 TBI; ZZ4/T56 on the ag
Transmission: A4, A4, slated to be a T56
I got my GM prop valve from Dal for $55 shipped. Can't go wrong there. If I were you, I'd get a new one. That car is 20 yrs old now, no telling what's in there.
Ed
Ed
Thread Starter
Member
Joined: Nov 2001
Posts: 143
Likes: 0
From: colorado springs, colorado, USA
Car: 83-84 camaro, 95 formula firehawk
Engine: 305, 305ho, 350tpi, 350 lt1, 383lt1
Transmission: 700r4, t-5, t56, m6
Axle/Gears: 3:90, 4:10, 3:50, and more
does anyone know how to adjust the valve? i made sure it was bled right, and i now amm 100% sertin its the valve. If i replace itcan i use any aftermarket valve? if not, what does it require, and if i get an aftermarket valve will it still ba able to kick to one side if a line breaks?
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Joined: Jul 1999
Posts: 18,457
Likes: 16
From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
There's no "adjustment" as such.
What are the brakes doing that makes you think it needs replacement?
When you bled the brakes, did you bench bleed the master cyl, or only bleed it on the car? If you did it on the car, you accomplished nothing, since the lines aren't at the highest point of the actual cyls; you can bleed it that way for a week, and the air wll still stay trapped.
What are the brakes doing that makes you think it needs replacement?
When you bled the brakes, did you bench bleed the master cyl, or only bleed it on the car? If you did it on the car, you accomplished nothing, since the lines aren't at the highest point of the actual cyls; you can bleed it that way for a week, and the air wll still stay trapped.
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