Topic: How can one tell...
in Forum: C3 Engines, Driveline and Handling
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if the proportioning valve on the brake system is bad? I mean, what are the symptoms?
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if brakes are system is bled correctly and calipers are good (not sticking or hanging up) the proportioning valve is what makes the front and back brakes give equal pressure. with disc brakes all around the car should stop equally. if you feel either front or back brakes grabbing at big difference than could be a sign of a bad valve but you have to make sure everything else is right.
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The brake light will come on and stay on until you quickly hit the brake pedal, if it is sticking.
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Are you having problems with yours, Jim, or you just curious?
If the valve is stuck at one end or the other, the pedal will be "spongy", and either the front or rear brakes will not work. The car will still stop, tho, and the pedal will not continue to the floor, as it would if there was a leak.
(If you've ever driven anything with the "Hydro-boost" brake system, you'll know the feeling I'm describing. Some air brake systems feel like this, too.
)
If the valve is stuck at one end or the other, the pedal will be "spongy", and either the front or rear brakes will not work. The car will still stop, tho, and the pedal will not continue to the floor, as it would if there was a leak.
(If you've ever driven anything with the "Hydro-boost" brake system, you'll know the feeling I'm describing. Some air brake systems feel like this, too.
)Joel Adams
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I'm having trouble getting the front brakes to completely grab (Lock Up).
It's like driving an ABS car right now...which is kinda cool but....
It's like driving an ABS car right now...which is kinda cool but....
Lifetime Member #73
The Money Pit.... and my niece
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Duncanville, TX - USA
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
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#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
That could be the p-valve, or the master cyl. IF the seal for the front brake side of the mc is leaking, it could cause a "weak" front brake apply.
Joel Adams
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Damn, I just put in a new master cylinder....
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Jim,
Did you buy a bargain master cylinder, or something like a Raybestos?
I learned that in the brake dept, you definately get what you pay for.
Also, bleed them again, just to be sure.
Alan
I'll re-bleed. I'm unsure how the differences in master cylinders could be so drastic. Anyone care to expound?
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in Forum: C3 Engines, Driveline and Handling
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