adjustable brake proportioning valve
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Re: adjustable brake proportioning valve (70 LS1)
The OE distribution block is not adjustable. For adjustment, you will have to install a valve similar to those offered by Wilwood. I think this is generally done on the rear wheels to prevent the rears from locking up before the fronts.
I have read that the way to set them up is to go to a large parking lot with an observer and do several panic stops. Adjust the rears until the rears and fronts lock up at the same time.
[Modified by flynhi, 4:54 PM 6/27/2003]
I have read that the way to set them up is to go to a large parking lot with an observer and do several panic stops. Adjust the rears until the rears and fronts lock up at the same time.
[Modified by flynhi, 4:54 PM 6/27/2003]
Thread Starter
Melting Slicks
Joined: May 2001
Posts: 2,812
Likes: 4
From: Gig Harbor Wa
Re: adjustable brake proportioning valve (flynhi)
Does the adjustable one replace the stock one or is it used in conjunction with it?
As far as adjusting it, that's pretty much what I figured. I was hoping there was another way, though. I really don't want to lock up my new tires several times to get it right.
As far as adjusting it, that's pretty much what I figured. I was hoping there was another way, though. I really don't want to lock up my new tires several times to get it right.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Re: adjustable brake proportioning valve (70 LS1)
Just to set the record staight, the stock unit is not a proportioning valve at all. Simply a distribution block.
This is one of the myths that just won't die.
This is one of the myths that just won't die.
Thread Starter
Melting Slicks
Joined: May 2001
Posts: 2,812
Likes: 4
From: Gig Harbor Wa
Re: adjustable brake proportioning valve (Mike Ward)
So let me see if I got this right. The factory block just splits the fluid front and rear. No biasing.
The aftermarket adjustable block goes in the line running to the back of the car and allows you to adjust the front to rear bias to ensure the front and rear lock up at the same time making the car more controlable.
Is that it?
thanks for all your help.
The aftermarket adjustable block goes in the line running to the back of the car and allows you to adjust the front to rear bias to ensure the front and rear lock up at the same time making the car more controlable.
Is that it?
thanks for all your help.
Melting Slicks
Joined: Jul 2002
Posts: 3,128
Likes: 3
From: Deltona (son of Deland and DAYTONA) FL
Re: adjustable brake proportioning valve (70 LS1)
all that happens in that stock valve is that there is a little piston that slides to block off a hydraulic circuit (front or rear) that looses pressure. Once if blocks off the circuit with low pressure, all the braking power is diverted to the other circuit.
The problem arises when you bleed the brakes. If you try to bleed the rears, often that piston cuts off fluid to the rear because of a lack of fluid in those pipes. The way around that is to crack the front AND rear bleeders and push some fluid through so that the rear circuit has some fluid behind the valve. Then you can close off the front and follow the bleeding sequence.
The problem arises when you bleed the brakes. If you try to bleed the rears, often that piston cuts off fluid to the rear because of a lack of fluid in those pipes. The way around that is to crack the front AND rear bleeders and push some fluid through so that the rear circuit has some fluid behind the valve. Then you can close off the front and follow the bleeding sequence.
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: adjustable brake proportioning valve (Mike Ward)
Just to set the record staight, the stock unit is not a proportioning valve at all. Simply a distribution block.
This is one of the myths that just won't die.
This is one of the myths that just won't die.
http://forums.corvetteforum.com/zerothread?id=323871
