Adjustable Proportioning Valve
Thread Starter
Melting Slicks
Joined: Dec 2015
Posts: 3,181
Likes: 732
From: Texas City, TX Texas
Adjustable Proportioning Valve
I am planning to swap out the power brakes on my '74 small block 4 speed to manual. I understand a different bracket is needed for the brake light switch. I see in the Eckler's catalog an adjustable proportioning valve with a switch on it. Has anyone used this product? I am refurbishing the entire brake system, lines, master cylinder, calipers, and rotors if they need it.
https://www.ecklerscorvette.com/prop...IaAntAEALw_wcB
https://www.ecklerscorvette.com/prop...IaAntAEALw_wcB
Old Pro Solo Guy
Joined: Dec 2017
Posts: 8,095
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From: Marlton NJ
I have used an adjustable proportioning valve before, but that was on a race car.. With twice as sticky as stock tires it tended to lockup the rear tires under 1.2G braking. There was so much front weight transfer that the rear would unweight so much it would skid.
On a street car just use the original type part.
On a street car just use the original type part.
Last edited by leigh1322; Mar 11, 2021 at 06:25 PM.
Thread Starter
Melting Slicks
Joined: Dec 2015
Posts: 3,181
Likes: 732
From: Texas City, TX Texas
I was thinking this would be easier than fabbing up the bracket for the switch, apparently they don't make them, plus the adjustability, while maybe not necessary, wouldn't hurt?
Le Mans Master
Joined: Aug 2017
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From: Cool Northern Michigan
I agree with leigh. Nothing wrong with the GM PV.
Usually an adjustable unit is for different types of brakes front to rear. Such as disc / drum because those require different pressure rates.
Usually an adjustable unit is for different types of brakes front to rear. Such as disc / drum because those require different pressure rates.
Thread Starter
Melting Slicks
Joined: Dec 2015
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From: Texas City, TX Texas
I think y'all are missing the point of my question. I need a different brake light switch, and this seems like a good way to get that, and adjustment to boot. For a hundred bucks, can it hurt to try it?
NCM Grand Opening Veteran
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From: South of giving a damn
St. Jude Donor '11, '17
I fail to see why the brake pedal mounted switch would be any different for power brakes or std brakes. If the pedal itself is different then I'd just fab a new bracket and not fool with the proportioning valve.
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Le Mans Master
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From: Watkinsville, GA and Glen Cove, NY
The brake light switch is on the pedal assembly and there are two different brackets depending on power or manual brakes, but they use the same switch, so your switch is still good. The manual bracket is longer since you have to use the top hole on the pedal for correct pedal ratio. The switch on the distribution block/proportioning valve is for the warning light. The different pedal brackets are readily available.
Last edited by 69ttop502; Mar 12, 2021 at 07:13 AM.
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Le Mans Master
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From: Fernandina Beach FL
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The OEM proportion valve has the "BRAKE" warning light indicator in the tach ( wired in parallel with the emergency brake)
The actual switch that turns on the rear brake lights is mounted on the pedal- and is the same for for power and manual.
**********************Missed your post Bill********************************
Here's the differences-
A picture is worth a thousands words...and it's a lot faster than I can type!!!
manual(unrestored) -power is the restored one
The actual switch that turns on the rear brake lights is mounted on the pedal- and is the same for for power and manual.
**********************Missed your post Bill********************************
Here's the differences-
A picture is worth a thousands words...and it's a lot faster than I can type!!!
manual(unrestored) -power is the restored one
Last edited by Richard454; Mar 12, 2021 at 07:51 AM.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
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From: New Braunfels Texas
I have used those low pressure brake light switches on Street Rods for years........my advice? Keep a spare in the glove tray as they are about as reliable as a 19 year old showing up for work.
I would somehow make your electric switch work.......
Jebby
I would somehow make your electric switch work.......
Jebby
Thread Starter
Melting Slicks
Joined: Dec 2015
Posts: 3,181
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From: Texas City, TX Texas
The brake light switch is on the pedal assembly and there are two different brackets depending on power or manual brakes, but they use the same switch, so your switch is still good. The manual bracket is longer since you have to use the top hole on the pedal for correct pedal ratio. The switch on the distribution block/proportioning valve is for the warning light. The different pedal brackets are readily available.
Richard, thanks for the pics.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
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From: New Braunfels Texas
That was my understanding, except I was under the impression the bracket for the brake light switch was hard to come by. You don't happen to have a part number? I also now understand the switch on the valve is for the dashboard warning light, not the brake lights in the rear bumper. Thanks guys for clearing that up for me.
Richard, thanks for the pics.
Richard, thanks for the pics.
Jebby
Dr. Detroit
Joined: Mar 2012
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From: New Braunfels Texas
Old Pro Solo Guy
Joined: Dec 2017
Posts: 8,095
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From: Marlton NJ
IIRC one pedal mounted brake light switch bracket is re-popped and not the other. Don't remember which MB/PB.
Looks like the PB one is available.
https://www.paragoncorvette.com/p-36...h-striker.aspx
Looks like the PB one is available.
https://www.paragoncorvette.com/p-36...h-striker.aspx