proportioning valve - faulty
Pro
Joined: Jun 2008
Posts: 674
Likes: 235
From: Louisville Kentucky
2023 C4 of the Year Finalist - Unmodified
2022 C3 of the Year Finalist - Unmodified
2021 C4 of the Year - Unmodified Finalist
2018 C4 of Year Finalist
2015 C4 of the Year Finalist
Is the "BRAKE" light illuminated on the dash?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
There is no "proportional" valve in any C3 (unless installed by an owner). It is a distribution block which sends brake fluid pressure to either the front wheel calipers, the rear wheel calipers or to both. The system is designed so that a leak in either the front or rear caliper set will cause a shuttle valve [inside that block] to shift such that the leaking side will be blocked from receiving pressurized brake fluid. If that occurs, the "BRAKE" warning light on the dash cluster should inform the driver of a problem with the brake system.
The ratio of braking power from front to back is incorporated into the design of the braking system and is NOT a function of the distribution block.
The ratio of braking power from front to back is incorporated into the design of the braking system and is NOT a function of the distribution block.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
If you are not getting enough fluid pressure to the fronts, maybe the front rubber hoses are at fault.
Not sure where your question is going here.
Pro
Joined: Jun 2008
Posts: 674
Likes: 235
From: Louisville Kentucky
2023 C4 of the Year Finalist - Unmodified
2022 C3 of the Year Finalist - Unmodified
2021 C4 of the Year - Unmodified Finalist
2018 C4 of Year Finalist
2015 C4 of the Year Finalist
The Proportioning Valve seldom goes bad. Usually if anything, the rear brakes are proportioned of fluid due to a leak downstream, getting less fluid when pedal is applied.
If you are not getting enough fluid pressure to the fronts, maybe the front rubber hoses are at fault.
Not sure where your question is going here.
If you are not getting enough fluid pressure to the fronts, maybe the front rubber hoses are at fault.
Not sure where your question is going here.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
I just removed my valve, ran the rear brake line to the rear section of the master cyl.....which is aluminum BTW, and hydro boost......and put a splitter/coupler in the front brake lines that runs to the front/forward of the m/cylinder.....solid as a rock for some 20 years.....and before the FIX was done, it was nothing but weird/spongy brake action....DOT 5 fluid too BTW......
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I just removed my valve, ran the rear brake line to the rear section of the master cyl.....which is aluminum BTW, and hydro boost......and put a splitter/coupler in the front brake lines that runs to the front/forward of the m/cylinder.....solid as a rock for some 20 years.....and before the FIX was done, it was nothing but weird/spongy brake action....DOT 5 fluid too BTW......
This is the real fix. I was installing the front brake line lock for drag racing and decided that a simple splitter/coupler was the best fix when rerouting my brake lines. One for the front and one for the back. It also seemed to me that the stock spliter valve was right next to my headers. Not a good thing either. My headers are glowing on long periods of WOT. Hot enough that I melted Energy Suspension poly locking red motor mounts. Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Instructor
Joined: Dec 2003
Posts: 167
Likes: 8
From: Blythewood S.C.
St. Jude Donor '14
Someone mentioned "rubber hoses" may be at fault. Just an interesting note about something I found on one of my vehicles that could apply to vettes also. I replaced the brake rubber hoses on my truck recently because when the brakes were applied, the truck would pull to the left or right. I found that the old hoses (2001 year model original hoses) were all but completely stopped up. The hoses incorporated some metal brackets for mounting to the "A" arm and the metal over the years had actually rusted causing the rubber hoses to be squeezed almost shut. After removing the old hoses, I could not blow compressed air through it. Cut the hose apart to verify what was happening. After the new hoses, the truck stopped straight, no pulling at all. Just a thought.
