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Old 10-25-2018, 12:13 PM   #1
FickleFinn
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Proportioning Valve

Has anyone found a proportioning valve that works on an all drum power brake system?
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Old 10-25-2018, 12:25 PM   #2
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Re: Proportioning Valve

Other than the factory one? What are you looking to accomplish?
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Old 10-25-2018, 12:36 PM   #3
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Re: Proportioning Valve

I have added power brakes to my 69 c10 and have drums all around. I guess the question is: do I need a proportioning valve and if so is there an after market one that will work as I don't have a factory valve.
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Old 10-25-2018, 12:44 PM   #4
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Re: Proportioning Valve

Did you change the master cylinder bore size?
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Old 10-25-2018, 12:52 PM   #5
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Re: Proportioning Valve

I bought the booster and master cylinder as a unit, the master cylinder is larger than the original.
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Old 10-25-2018, 01:11 PM   #6
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Re: Proportioning Valve

The factory used the larger (1/4") line to the rear brakes as a way of slowing the application of the rear brakes. That should still work for you. The best thing at this point is to find a safe area to do some brake testing and do some hard stops and see if the rears lockup too easily. If so then adding a adjustable proportioning valve will allow you to slow the application of the rear brakes. Willwood makes good products and they have nice one piece units.

https://www.wilwood.com/MasterCylind...CylinderValves
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Old 10-25-2018, 04:28 PM   #7
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Re: Proportioning Valve

You shouldn’t “need” a proportioning valve in your setup. Factory only had a distribution block that was a safety feature (and is connected to your dash brake light). Proportioning, for lack of a better term, is done by the stock mc to some extent (and fine tuning the ol star wheels is a good idea as mentioned).
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Old 10-25-2018, 05:11 PM   #8
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Re: Proportioning Valve

Quote:
Originally Posted by jocko View Post
You shouldn’t “need” a proportioning valve in your setup. Factory only had a distribution block that was a safety feature (and is connected to your dash brake light). Proportioning, for lack of a better term, is done by the stock mc to some extent (and fine tuning the ol star wheels is a good idea as mentioned).
That's the answer you need.
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Old 10-26-2018, 07:44 AM   #9
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Thumbs up Re: Proportioning Valve

All 4 wheels are drum brakes you don't need a proportioning valve as stated they all work the same way. The proportioning valve was for disc brakes up front and drums in the rear.
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