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Proportion valve centering tool

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Old 06-28-2024, 01:54 PM
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Proportion valve centering tool

Since I've owned my car, I've always felt like the brakes were terrible, and that the rear brakes didn't do anything. I recently put on a second set of new hoses, and new (reman) rear calipers, and still no improvement. So then I started reading about the proportioning valve and how it has to stay centered to properly bleed the brakes, and found a tool on Amazon. I used it today and re-bled the brakes, and I finally have normal feeling brakes without a mushy pedal. Seems like most people don't know much about these, I know I certainly didn't.

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Old 06-28-2024, 02:07 PM
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Re: Proportion valve centering tool

Originally Posted by 80schild
Since I've owned my car, I've always felt like the brakes were terrible, and that the rear brakes didn't do anything. I recently put on a second set of new hoses, and new (reman) rear calipers, and still no improvement. So then I started reading about the proportioning valve and how it has to stay centered to properly bleed the brakes, and found a tool on Amazon. I used it today and re-bled the brakes, and I finally have normal feeling brakes without a mushy pedal. Seems like most people don't know much about these, I know I certainly didn't.

https://www.amazon.com/JEUCLEL-Propo...zcF9hdGY&psc=1

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Old 06-28-2024, 08:34 PM
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Re: Proportion valve centering tool

My issue was not being able to properly bleed the brakes. Everytime I would try, the darned valve would move blocking the flow. This little tool keeps it centered.
Old 06-29-2024, 06:42 AM
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Re: Proportion valve centering tool

Originally Posted by 80schild
My issue was not being able to properly bleed the brakes. Everytime I would try, the darned valve would move blocking the flow. This little tool keeps it centered.
Good find. I've never heard of that. A lot of our issues are just weak rear brakes in general. My rear tires would spin with my foot on the brakes waiting at a light. Especially if the road was a little oily. The spring upgrade made a world of difference. I can't overstate the effectiveness of that mod.
Old 06-29-2024, 09:01 AM
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Re: Proportion valve centering tool

Never heard of it either, what does it do? I've never had an issue with spongy brakes, seems like I've read around here that before the redesign, the old style rear disks didn't work so well, maybe you found the secret to getting them to work. GM redesigned them in 88 or 89 if I recall.
Old 06-29-2024, 11:21 AM
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Re: Proportion valve centering tool

Originally Posted by LiquidBlue
Never heard of it either, what does it do? I've never had an issue with spongy brakes, seems like I've read around here that before the redesign, the old style rear disks didn't work so well, maybe you found the secret to getting them to work. GM redesigned them in 88 or 89 if I recall.
You are correct. The brakes on the 87 were only there to hold the studs to bolt on the rear wheels.
Old 06-29-2024, 11:55 AM
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Re: Proportion valve centering tool


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Old 06-29-2024, 03:09 PM
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Re: Proportion valve centering tool

Originally Posted by LiquidBlue
Never heard of it either, what does it do? I've never had an issue with spongy brakes, seems like I've read around here that before the redesign, the old style rear disks didn't work so well, maybe you found the secret to getting them to work. GM redesigned them in 88 or 89 if I recall.
That valve is designed to cut off fluid from the brakes if it senses a ruptured hose or other fluid loss. So if it senses fluid loss to the rear, it cuts it off to preserve the brakes in the front. The problem is that this will also happen when you open the bleeder screw, because the valve can't tell the difference. This bleeder tool will keep the valve centered so that you can bleed them normally. And after you're done, you won't have to stomp on the pedal to try to center the valve again.
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