Brakes Looking to upgrade or get the most out of what you have stock? All brake discussions go here!

Proportioning Valves

Old 01-23-2011, 06:52 PM
  #1  
Senior Member
Thread Starter
iTrader: (2)
 
383 Power's Avatar
 
Join Date: Jul 2010
Location: Shreveport, LA
Posts: 500
Likes: 0
Received 1 Like on 1 Post
Car: 1982 SC/1984 Z28
Engine: 305 4BBL/305 4BBL H.O.
Transmission: 700R4/700R4
Axle/Gears: 4th Gen 3.23 Posi/3.73 10 Bolt
Proportioning Valves

I have a 3rd Gen Proportioning Valve off of a 1985 Firebird with Disc Brakes. It's rear was a Borg-Warner. I'm going to use a Rear out of a 4th gen and the disc brakes are larger. Could i use the Valve out of the 85, or do i have to purchase a special valve? My Car is a 1982.

Since i'm Replacing all of the Brake Lines, Cables, and Calipers, should i also replace the Dampeners, or are those a non-wearing item?
Old 01-23-2011, 07:15 PM
  #2  
Member

iTrader: (7)
 
chevysquid's Avatar
 
Join Date: Sep 2003
Location: Coupeville, Washington
Posts: 267
Likes: 0
Received 0 Likes on 0 Posts
Car: 1986 IROC T-TOP
Engine: 350
Transmission: 700-R4
Re: Proportioning Valves

Some of the earlier models had different threading on the lines going to the proportioning valve. Coincidently, I do have one of the earlier model cast iron valves if you need to find one.
Old 01-23-2011, 07:18 PM
  #3  
Senior Member
Thread Starter
iTrader: (2)
 
383 Power's Avatar
 
Join Date: Jul 2010
Location: Shreveport, LA
Posts: 500
Likes: 0
Received 1 Like on 1 Post
Car: 1982 SC/1984 Z28
Engine: 305 4BBL/305 4BBL H.O.
Transmission: 700R4/700R4
Axle/Gears: 4th Gen 3.23 Posi/3.73 10 Bolt
Re: Proportioning Valves

No, i have the early version for disc brakes, but i didn't know if it would work with 1994 Disc Brakes.

Thank you for the offer though
Old 01-23-2011, 07:39 PM
  #4  
Member

iTrader: (7)
 
chevysquid's Avatar
 
Join Date: Sep 2003
Location: Coupeville, Washington
Posts: 267
Likes: 0
Received 0 Likes on 0 Posts
Car: 1986 IROC T-TOP
Engine: 350
Transmission: 700-R4
Re: Proportioning Valves

I think it was that the earlier ones were SAE threaded and everything else after is metric. From what I've read either one would work though.
Old 01-23-2011, 08:37 PM
  #5  
Moderator

iTrader: (5)
 
JamesC's Avatar
 
Join Date: Aug 1999
Location: Lawrence, KS
Posts: 19,282
Received 93 Likes on 68 Posts
Car: Met. Silver 85 IROC/Sold
Engine: 350 HO Deluxe (350ci/330hp)
Transmission: T-5 (Non-WC)
Axle/Gears: Limited Slip 3.23's
Re: Proportioning Valves

I discussed some of this with you in the thread to follow:

https://www.thirdgen.org/forums/susp...list-find.html

To perhaps better clarify: As I understand it, the following valves increase in bias from first to last:
Disc/drum
Disc/disc (10.5" rotors with Delco-Moraine calipers)
Disc/disc (11.7" rotor with PBR's, the so-called 1LE, or in your case the LT1, 93-97)

So you need either a 1LE combination valve or an adjustable for best braking performance.

Check the following link for more about master cylinders, combination valves, speedo gears and parking break cables (the braking systems are the same for the 9- and 10-bolt):

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

Last edited by JamesC; 01-23-2011 at 08:48 PM.
Old 01-23-2011, 11:25 PM
  #6  
Senior Member
Thread Starter
iTrader: (2)
 
383 Power's Avatar
 
Join Date: Jul 2010
Location: Shreveport, LA
Posts: 500
Likes: 0
Received 1 Like on 1 Post
Car: 1982 SC/1984 Z28
Engine: 305 4BBL/305 4BBL H.O.
Transmission: 700R4/700R4
Axle/Gears: 4th Gen 3.23 Posi/3.73 10 Bolt
Re: Proportioning Valves

Thank you! THAT was the information that i was seeking. I'm sorry to ask so many questions, but since i've never done anything like this before, I want to leave nothing to chance. The more i do, the more questions i have, and you guys are a wonderful resource to tap. I have to say that I'm not looking forward to plumbing in a new Proportioning valve. I would just get the 4th Gen's Master Cylinder too, but i guess the hoses running from the body would be a different size too. There just seems to be no way around this. I was planning on making the swap on Thursday. It seems i'll have to delay until next week.
Old 01-24-2011, 12:02 AM
  #7  
Supreme Member
iTrader: (7)
 
ebmiller88's Avatar
 
Join Date: Mar 2001
Location: Fort Mill, SC, USA
Posts: 6,420
Likes: 0
Received 4 Likes on 4 Posts
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
Re: Proportioning Valves

James, you are a true benefit to the Forum. Your knowledge base, research, and support to the site is greatly appreciated.

Ed Miller
Old 01-24-2011, 12:09 AM
  #8  
Senior Member
Thread Starter
iTrader: (2)
 
383 Power's Avatar
 
Join Date: Jul 2010
Location: Shreveport, LA
Posts: 500
Likes: 0
Received 1 Like on 1 Post
Car: 1982 SC/1984 Z28
Engine: 305 4BBL/305 4BBL H.O.
Transmission: 700R4/700R4
Axle/Gears: 4th Gen 3.23 Posi/3.73 10 Bolt
Re: Proportioning Valves

Originally Posted by ebmiller88
James, you are a true benefit to the Forum. Your knowledge base, research, and support to the site is greatly appreciated.

Ed Miller
Agreed......... The Link was AWESOME! This is making me feel better about this swap. He's done it now though. I'll probably bug the hell out of the guy from now on. I'll try not to be too much of a Pain though.
Old 01-24-2011, 12:19 AM
  #9  
Senior Member
Thread Starter
iTrader: (2)
 
383 Power's Avatar
 
Join Date: Jul 2010
Location: Shreveport, LA
Posts: 500
Likes: 0
Received 1 Like on 1 Post
Car: 1982 SC/1984 Z28
Engine: 305 4BBL/305 4BBL H.O.
Transmission: 700R4/700R4
Axle/Gears: 4th Gen 3.23 Posi/3.73 10 Bolt
Re: Proportioning Valves

Here is the Valve i Ordered:

http://www.summitracing.com/parts/WIL-260-11179/

It has 2 Inlets, and 3 Outlets just like the original. It even looks like it will fit on the bracket the same way and the threads appear to be SAE.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
SPEEDY Z28
Brakes
16
04-18-2016 02:46 PM
sleprock
Power Adders
9
09-24-2015 04:33 PM
HikoriYami
Transmissions and Drivetrain
2
09-21-2015 07:11 PM
355tpipickup
Tech / General Engine
9
09-13-2015 11:35 PM
sandman92084
Tech / General Engine
13
09-12-2015 10:27 PM


Thread Tools
Search this Thread
Quick Reply: Proportioning Valves



All times are GMT -5. The time now is 06:49 PM.