Proportioning Valve Removal
Thread Starter
Drifting
Joined: May 2004
Posts: 1,258
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From: Huntsville Alabama
Proportioning Valve Removal
Ok well I know this has been discussed before, but since I can not search the archives to find the threads I am going to ask. Who has removed the proportioning valve. Mine has decided it wants to leak and thats the last of the brake puzzle that has not been replaced. My car is a 75. As I understand it 75 up has a valve on the back of the brass block. If this brake system has been the same since 63 when the technology was introduced in the c2 then can I remove the proportioning valve all together and the brakes still work. Also for those that have done it besides some unions, T's and brake line what else is needed. Thanks
Melting Slicks
Joined: Aug 2001
Posts: 3,050
Likes: 124
From: Wichita KS
Ok well I know this has been discussed before, but since I can not search the archives to find the threads I am going to ask. Who has removed the proportioning valve. Mine has decided it wants to leak and thats the last of the brake puzzle that has not been replaced. My car is a 75. As I understand it 75 up has a valve on the back of the brass block. If this brake system has been the same since 63 when the technology was introduced in the c2 then can I remove the proportioning valve all together and the brakes still work. Also for those that have done it besides some unions, T's and brake line what else is needed. Thanks
(Weight transfer to the front during rapid deceleration reduces rear traction and can result in rear wheel skid. The proportioner part of the combination valve reduces the rear brake pressure and delays rear wheel skid.)
Thread Starter
Drifting
Joined: May 2004
Posts: 1,258
Likes: 0
From: Huntsville Alabama
thanks. I do not have any warning lights. Took out all the factory stuff and have autometer guages and custom made turn signal and high beam indicators. So no idiot lights for my car. With that said 120 plus shipping is ridiculous for this part.
Melting Slicks
Joined: Aug 2001
Posts: 3,050
Likes: 124
From: Wichita KS
The problem IS NOT the warning lights. The problem is regulating brake line pressure to the rear brakes. Without some means of proportioning (reducing) rear brake pressure, the rear brakes will lock up and skid. The proportioning valve is to delay the onset of rear brake lockup.
Last edited by mapman; Dec 29, 2011 at 09:17 PM.
Thread Starter
Drifting
Joined: May 2004
Posts: 1,258
Likes: 0
From: Huntsville Alabama
would this one work http://www.summitracing.com/parts/CLP-PV-2/ it looks the same as the one on the vette.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Only 2 places they can leak, the switch oring and the proportioning valve relief.
You can unscrew the proportioning valve from the differential valve and then gut the prop valve inside. Then you must put a pipe plug in the hole on the side. Cost is about an hour and less than a buck for the allen pipe plug.
This will essentially give you the same valve as an earlier C3 or C2 and the front/rear will still be separate circuits for safety.
You can unscrew the proportioning valve from the differential valve and then gut the prop valve inside. Then you must put a pipe plug in the hole on the side. Cost is about an hour and less than a buck for the allen pipe plug.
This will essentially give you the same valve as an earlier C3 or C2 and the front/rear will still be separate circuits for safety.
Thread Starter
Drifting
Joined: May 2004
Posts: 1,258
Likes: 0
From: Huntsville Alabama
Only 2 places they can leak, the switch oring and the proportioning valve relief.
You can unscrew the proportioning valve from the differential valve and then gut the prop valve inside. Then you must put a pipe plug in the hole on the side. Cost is about an hour and less than a buck for the allen pipe plug.
This will essentially give you the same valve as an earlier C3 or C2 and the front/rear will still be separate circuits for safety.
You can unscrew the proportioning valve from the differential valve and then gut the prop valve inside. Then you must put a pipe plug in the hole on the side. Cost is about an hour and less than a buck for the allen pipe plug.
This will essentially give you the same valve as an earlier C3 or C2 and the front/rear will still be separate circuits for safety.
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Thread Starter
Drifting
Joined: May 2004
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From: Huntsville Alabama
Yup and I did what noonie suggested. I don't feel the need to get raped by the vendors just because it is a corvette and pay a premium. Its that same in the musical instrument world you pay for the name.
Race Director
Joined: Jul 2001
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The problem IS NOT the warning lights. The problem is regulating brake line pressure to the rear brakes. Without some means of proportioning (reducing) rear brake pressure, the rear brakes will lock up and skid. The proportioning valve is to delay the onset of rear brake lockup.
Melting Slicks
Joined: Jan 2003
Posts: 2,713
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From: Shreveport LA
LA Events Coordinator
Nope, I'm having a new proportioning valve replaced right now, on my 75 Vert. Bought it from Zip Products for $99.95. I thought about going through Summit Racing to get a universal valve, for about $45.00, I figure....to go FAST is one thing, but to SAFELY STOP is FAR MORE important....so the brakes is one area I don't monkey with...if it calls for a certain part, I get that part...$100 is pretty cheap insurance compared to a life of paralysis, or lawsuits out the ying-yang...just because something failed in my braking system because I used a "non stock" or universal part....Just my opinion.... 
Last edited by vetteguy75; Dec 30, 2011 at 02:45 PM.
Team Owner
Joined: Aug 1999
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From: Ontario
Actually the 1974 does have a proportioning valve.
https://www.paragoncorvette.com/p-35...ing-valve.aspx
Race Director
Joined: Jul 2001
Posts: 15,892
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Many vendors use incorrect and misleading terminology for this part- including Paragon. Here's the valve for '70-'73 cars that most certainly has no 'proportioning' capabilities.
https://www.paragoncorvette.com/p-35...ing-valve.aspx
https://www.paragoncorvette.com/p-35...ing-valve.aspx
Drifting
Joined: Jul 2002
Posts: 1,944
Likes: 20
From: The only Corvettes in Highett Victoria
Ooops!!!
Many vendors use incorrect and misleading terminology for this part- including Paragon. Here's the valve for '70-'73 cars that most certainly has no 'proportioning' capabilities.
https://www.paragoncorvette.com/p-35...ing-valve.aspx
https://www.paragoncorvette.com/p-35...ing-valve.aspx
I now think that you're correct. It looks like my cars have the distribution block with the warning light switch down on the chassis, not sure now if it's a prop. valve or not.
My apologies.
Regards from Down Under.
aussiejohn