Front Brake Prop Valve

sixty8 · 03-21-2010, 02:36 PM

I am installing a proportioning valve for my front brakes. The car is a 68 Camaro that came with factory front disks and the stock system includes a proportioning valve. I have my line-lock installed between the factory prop valve and distribution block. Should I install the new prop valve between the line-lock and distribution block? Does it matter if it is before or after the line-lock?

magnumv8 · 03-21-2010, 05:17 PM

The line loc MUST be installed after the prop valve....this ensures that when you take your foot off the brake pedal that brake pressure is relieved from both sides of the valve to prevent it from "sensing" a pressure "leak" which would make it transfer all braking power over to the front brakes...if the valve would then stick in this position you may not notice it til you hit the brakes at the top end of the run which could lead to a catastrophic accident due to only having front brakes.....

the NHRA rulebook also tells you that the line loc must be installed AFTER the prop valve......

now if you are talking about an adjustable prop valve for additional front brake control (too much brake pressure) as long as the line loc is in the correct location there should be no problems with this valve plumbed in before or after the line loc as long as it also is plumbed in after the factory prop valve.....

D L RAMBO.....

sixty8 · 03-21-2010, 10:15 PM

I am installing it for additional front brake control. I have a Strange front brake kit and they suggest running an adjustable valve and setting the caliper pressure between 650-700 psi. I think that I may replace the original prop valve with the Wilwood valve rather than running 2 prop valves. Thanks for the reply.

Billy Nees · 03-22-2010, 06:56 AM

Quote:

Originally Posted by sixty8

I am installing it for additional front brake control. I have a Strange front brake kit and they suggest running an adjustable valve and setting the caliper pressure between 650-700 psi. I think that I may replace the original prop valve with the Wilwood valve rather than running 2 prop valves. Thanks for the reply.

What you are calling an "original prop valve" is only a distribution block with a check valve in it. In case the front or rear brakes fail the valve will switch to one side or the other so you would have some brake.

03-21-2010, 02:36 PM	#1
sixty8 Junior Member Join Date: Sep 2007 Posts: 14 Likes: 0 Liked 0 Times in 0 Posts	Front Brake Prop Valve I am installing a proportioning valve for my front brakes. The car is a 68 Camaro that came with factory front disks and the stock system includes a proportioning valve. I have my line-lock installed between the factory prop valve and distribution block. Should I install the new prop valve between the line-lock and distribution block? Does it matter if it is before or after the line-lock?

03-21-2010, 05:17 PM	#2
magnumv8 Member Join Date: Feb 2009 Location: Coraopolis, Pa. Posts: 172 Likes: 0 Liked 0 Times in 0 Posts	Re: Front Brake Prop Valve The line loc MUST be installed after the prop valve....this ensures that when you take your foot off the brake pedal that brake pressure is relieved from both sides of the valve to prevent it from "sensing" a pressure "leak" which would make it transfer all braking power over to the front brakes...if the valve would then stick in this position you may not notice it til you hit the brakes at the top end of the run which could lead to a catastrophic accident due to only having front brakes..... the NHRA rulebook also tells you that the line loc must be installed AFTER the prop valve...... now if you are talking about an adjustable prop valve for additional front brake control (too much brake pressure) as long as the line loc is in the correct location there should be no problems with this valve plumbed in before or after the line loc as long as it also is plumbed in after the factory prop valve..... D L RAMBO..... Last edited by magnumv8; 03-21-2010 at 05:29 PM. Reason: additional info

03-21-2010, 10:15 PM	#3
sixty8 Junior Member Join Date: Sep 2007 Posts: 14 Likes: 0 Liked 0 Times in 0 Posts	Re: Front Brake Prop Valve I am installing it for additional front brake control. I have a Strange front brake kit and they suggest running an adjustable valve and setting the caliper pressure between 650-700 psi. I think that I may replace the original prop valve with the Wilwood valve rather than running 2 prop valves. Thanks for the reply.