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Old 08-13-2022, 12:30 PM   #1
Minkota
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Proportioning valve line adapter

I just purchases this proportioning valve and went to install on my 67 PU. The lines on the truck are different than the ports on the valve. Does anyone know what adapters I need to order? The lines on the truck appear to be original.
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Old 08-13-2022, 01:27 PM   #2
72SB
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Re: Proportioning valve line adapter

I guess 67 is different than 72 as I have the CCP PV and my lines connected directly

Maybe if you search for replacement brake lines for your truck it will nte the fitting sizes and then you get that size adapter to the sizes noted on your new PV 411

I had to do the same thing on my 67 Camaro for a Right Stuff power disc kit I put on
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Old 08-13-2022, 02:39 PM   #3
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Re: Proportioning valve line adapter

The front port on the valve is too small and the rear port on the valve is too big. Both lines going down to the brakes are the same size.

Nobody locally has anything that will fit so I am hoping someone can tell me the correct fittings to order.
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Old 08-13-2022, 03:58 PM   #4
jocko
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Re: Proportioning valve line adapter

The inlet and outlet sizes are listed in the notes of the ad you posted - that might help you find what you need, but you need to know the size you are adapting from/to from MC and to brake lines. Having said that, the fittings are always a pain no matter what you do. I'd recommend taking the prop valve and your lines from your mc down to the parts store and do a little trial and error - I've had to do that every time. But the sizes listed in the settings will help you narrow down candidate adapters pretty quickly once you're there, if they are labeled.

The prop valve pictured is for a disk/drum setup, aka 71+ (or older trucks with a disk/drum conversion). Disk & drum lines are 3/16" & 1/4", respectively. Your 67's would have been all 1/4" originally. I can't tell from the pic, but are ALL the lines that came with your valve the same size? If they are all 1/4", then it should be correct for a drum/drum system. If one line is smaller, that should be for the disk system. Did you convert to disk/drum or are you still all drums? If you converted to disk/drum, are you switching out the original front system 1/4" lines for 3/16" replacements?

Lastly, is your truck a 1/2 or 3/4 ton? That matters from the perspective of the master cylinder. on 3/4+, the front res is for the rear brakes (and generally connects to the rear system on the prop valve). For a 1/2 ton, it's much more intuitive - front res, front system connections on prop valve, front brakes).
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Old 08-13-2022, 04:05 PM   #5
pontiacvince
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Re: Proportioning valve line adapter

What Jocko said.
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Old 08-13-2022, 04:12 PM   #6
Minkota
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Re: Proportioning valve line adapter

Quote:
Originally Posted by jocko View Post
The inlet and outlet sizes are listed in the notes of the ad you posted - that might help you find what you need, but you need to know the size you are adapting from/to from MC and to brake lines. Having said that, the fittings are always a pain no matter what you do. I'd recommend taking the prop valve and your lines from your mc down to the parts store and do a little trial and error - I've had to do that every time. But the sizes listed in the settings will help you narrow down candidate adapters pretty quickly once you're there, if they are labeled.

The prop valve pictured is for a disk/drum setup, aka 71+ (or older trucks with a disk/drum conversion). Disk & drum lines are 3/16" & 1/4", respectively. Your 67's would have been all 1/4" originally. I can't tell from the pic, but are ALL the lines that came with your valve the same size? If they are all 1/4", then it should be correct for a drum/drum system. If one line is smaller, that should be for the disk system. Did you convert to disk/drum or are you still all drums? If you converted to disk/drum, are you switching out the original front system 1/4" lines for 3/16" replacements?

Lastly, is your truck a 1/2 or 3/4 ton? That matters from the perspective of the master cylinder. on 3/4+, the front res is for the rear brakes (and generally connects to the rear system on the prop valve). For a 1/2 ton, it's much more intuitive - front res, front system connections on prop valve, front brakes).
I took it all down to several parts stores (advanced, orielys, auto zone Napa, and Home Depot) nobody local has the fittings I need.

I do have disc/drums, both lines coming from the brakes are the same size. Proportioning valve to master lines came with the valve and they fit perfectly. It’s connecting to the lines going out to the brakes that I am having trouble finding.
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Old 08-13-2022, 04:22 PM   #7
70STOVEBOLT
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Re: Proportioning valve line adapter

I will try to remember to look at mine when I get home and let you know. My truck has 1/4 lines and discs but with a stock 71-72 prop valve.
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Old 08-13-2022, 04:38 PM   #8
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Re: Proportioning valve line adapter

FWIW once I did find what my line size was (fittings) I bought my adapters from Amazon. They were from Inline Tube. $4-$5 each. That was for my 67 Camaro, not a C10, which was a drum/drum car I converted to disc/drum

OP, IDK what your front line fitting size is but my 67 Camaro I needed these:

One stock front line needed a 1/2-20 F to 3/8-24 M inverted flare
Rear line needed a 9/16-18 M to 7/16-24F inverted flare
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Old 08-13-2022, 05:16 PM   #9
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Re: Proportioning valve line adapter

Once you figure out the fittings, keep an eye on that front metering valve...those CPP combo valves are well known for leaking.
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