Which Proportioning valve for 4 Wheel Discs?

Posted By: edco440

Which Proportioning valve for 4 Wheel Discs? - 08/19/13 10:59 PM

I have a 4 wheel disc brake system installed, fronts are Viper rears are Cobra. I have what appears to be a drum brake distribution block/proportioning valve according to Inline tube. I am confused as what I should get/have for a distribution block. I am going to install a Wilwood rear brake adjustable Prop.Valve at the Master Cylinder which is a new Plastic/aluminum MoPar Perf. unit from Dr. Diff. Can anyone explain exactly what I need?

Thanks,,,,Eddie

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Posted By: Lefty

Re: Which Proportioning valve for 4 Wheel Discs? - 08/19/13 11:54 PM

Quote:

Can anyone explain exactly what I need?

Get rid of that valve in the picture! One of the advantages of 4 wheel disc is the lack of the need for valves. You may not even need the Wilwood adjustable if the rear piston size and pad compound give you the brake balance you want.

Start with no valve at all, then on a wet/damp WIDE stretch of road or better a big parking lot - do panic brake stops at 50 mph. If the rear of the car consistently wants to break loose and come around on you add the Wilwood valve and adjust it till the car stops trying to swap ends. Don't go too tight or the car will not want to turn because the rear is acting like an anchor. Great for trailer brakes, bad for performance handling.

Posted By: AndyF

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 12:21 AM

The prop valve is needed when you have disc up front and drums in the rear. The drum brakes self energize so you need a valve to "blow off" the pressure. Otherwise the rear drums will always lock up during a hard stop.

With discs on all four corners you don't really need a prop valve since everything is linear. But you can get into a problem if you change the weight distribution or drive in different weather conditions.

Best thing to do is to set up the brakes so you're starting off with the correct proportions front to rear. Typically you want the rears to do 1/3 of the braking. So you set the rear up to have 1/2 the brake force of the front brakes. That rule of thumb works for most nose heavy muscle cars.

Posted By: edco440

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 12:22 AM

Thanks Lefty! Appreciate it! I have a complete set of new lines,,got em a few days ago from inline tube. How do I use these lines that go to some sort of Prop. valve/distribution block. Do I just get a set of "adaptors or joints" to extend the lines to each wheel? Thanks for the input!

BTW,, I called Inline tube,,they wont take the lines back,,said it's their policy,,therefore the question. Also last but not least,,can you or anyone suggest a stainless steel brake line flaring tool? The Napa tool is just not rigid enough, and most I seen on Amazon or other brake tool suppliers are the same flimsy tool and is not for stainless. I don't mind spending good money for proper high quality tooling.

Posted By: edco440

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 12:31 AM

Quote:

The prop valve is needed when you have disc up front and drums in the rear. The drum brakes self energize so you need a valve to "blow off" the pressure. Otherwise the rear drums will always lock up during a hard stop.

With discs on all four corners you don't really need a prop valve since everything is linear. But you can get into a problem if you change the weight distribution or drive in different weather conditions. Thanks Andy! The info I have which is gleaned from your B-Body Book shows the 2004 Viper Calipers as 5.480 inches of Piston area. The rear Cobra Calipers are approx. 2.25 according to my Calc. this should be close to 1/3 the braking force as the fronts. But I did not Calc. the rotor size so it's a "guess",, 13x1.250 fronts 11.7 X 1" rears,,, the book really helped me,,thanks!!
Best thing to do is to set up the brakes so you're starting off with the correct proportions front to rear. Typically you want the rears to do 1/3 of the braking. So you set the rear up to have 1/2 the brake force of the front brakes. That rule of thumb works for most nose heavy muscle cars.

Posted By: edco440

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 12:51 AM

Thank You Andy!

Posted By: Lefty

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 01:01 AM

Quote:

I called Inline tube,,they wont take the lines back,,said it's their policy,,therefore the question. Also last but not least,,can you or anyone suggest a stainless steel brake line flaring tool? The Napa tool is just not rigid enough, and most I seen on Amazon or other brake tool suppliers are the same flimsy tool and is not for stainless. I don't mind spending good money for proper high quality tooling.

You can get 3/16 female/female junctions to connect the lines. Or you could go ahead and plumb in the Wilwood adjustable and leave it wide open until you can test for brake balance.

Stainless steel lines are tough to double flair. Speedway has a tool they "say" will do stainless, but I'll believe it when I see it.

I bought a really nice Mastercool flaring tool and ruined the 3/16 die doing double flairs on SS even after annealing the ends before flaring. I switched to the 90/10 copper/nickel brake line and never looked back. It double flairs like butter and the nickel finish is nice.

Posted By: edco440

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 02:37 AM

Quote:

Quote:

I called Inline tube,,they wont take the lines back,,said it's their policy,,therefore the question. Also last but not least,,can you or anyone suggest a stainless steel brake line flaring tool? The Napa tool is just not rigid enough, and most I seen on Amazon or other brake tool suppliers are the same flimsy tool and is not for stainless. I don't mind spending good money for proper high quality tooling.

You can get 3/16 female/female junctions to connect the lines. Or you could go ahead and plumb in the Wilwood adjustable and leave it wide open until you can test for brake balance.

Stainless steel lines are tough to double flair. Speedway has a tool they "say" will do stainless, but I'll believe it when I see it.

I bought a really nice Mastercool flaring tool and ruined the 3/16 die doing double flairs on SS even after annealing the ends before flaring. I switched to the 90/10 copper/nickel brake line and never looked back. It double flairs like butter and the nickel finish is nice.

Thanks Lefty,,I'll do just that. Yeah, Stainless is a tough metal to work with,,I really hate to waste the new lines,,guess I'll sell em and switch over to either OEM or CN 90/10, the only flaring tool I like is the Eastwood flaring tool that has a rigid set-up but man,,250 bucks! I'll get some male/female fittings, but 1 thing I just thought of Lefty,,if I don't use the Prop. Valve,,how would I activate the brake light warning switch/idiot light? Just Omit it? I have no problem with daily maintenance/brake system check,,leaks,,soft spongy pedal ect Thanks again for your time/advice

Eddie

Posted By: DoctorDiff

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 05:46 AM

You can install a simple drum brake distribution block in place of the factory prop valve.

Posted By: edco440

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 07:09 AM

Quote:

You can install a simple drum brake distribution block in place of the factory prop valve.

Thanks Cass, I saw that on Classic tubes web site but didn't realize that a drum brake DB would work,,nice tip! Thanks! I have a few buds with project Muscle cars and trucks,,so I ordered the Eastwood Pro-Flaring tool, I'm going to use the stainless lines. I'll post how it all worked out. If nothing else it should help my popularity

Posted By: dangina

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 02:19 PM

I as wondering if you just go from the rear brakes-->wilwood adjustable knob--->master cylinder

and for the front brakes just use a "Tee" to the front brakes to get rid of the propotioning valve altogether. I'm makining my own brake lines, I also bought the mastercool hydraulic brake line tool and its the cats meow

Posted By: John_Kunkel

Re: Which Proportioning valve for 4 Wheel Discs? - 08/20/13 06:57 PM

Quote:

I called Inline tube,,they wont take the lines back,,said it's their policy

If you want to make use of the lines you're stuck with, just remove the plug from the prop valve and remove the spring and valve; reinstall the plug and the prop valve becomes a distribution block.

I wouldn't consider putting a prop valve in a 4-wheel disc system until some road testing was done.

Posted By: BradD

Re: Which Proportioning valve for 4 Wheel Discs? - 08/23/13 02:14 AM

This is what I am going to do with a 66 Charger with 4W discs. Currently has the same Prop valve as the one pictured above. It doesn't stop worth a crap at this time. And it has stainless lines already installed(which are a pain to seal).

Posted By: DAYCLONA

Re: Which Proportioning valve for 4 Wheel Discs? - 08/23/13 05:00 AM

Quote:

I as wondering if you just go from the rear brakes-->wilwood adjustable knob--->master cylinder

and for the front brakes just use a "Tee" to the front brakes to get rid of the propotioning valve altogether. I'm makining my own brake lines, I also bought the mastercool hydraulic brake line tool and its the cats meow

Yes, this is what I do on all my 4 wheel disc applications, with no issues, no factory distribution blocks, or gutted PV's,...results in a cleaner line organization in the engine compartment, less connections, less potential for leaks/issues

Mike

Posted By: jcc

Re: Which Proportioning valve for 4 Wheel Discs? - 08/23/13 04:35 PM

Quote:

Quote:

I as wondering if you just go from the rear brakes-->wilwood adjustable knob--->master cylinder

and for the front brakes just use a "Tee" to the front brakes to get rid of the propotioning valve altogether. I'm makining my own brake lines, I also bought the mastercool hydraulic brake line tool and its the cats meow

Yes, this is what I do on all my 4 wheel disc applications, with no issues, no factory distribution blocks, or gutted PV's,...results in a cleaner line organization in the engine compartment, less connections, less potential for leaks/issues

Mike

Posted By: edco440

Re: Which Proportioning valve for 4 Wheel Discs? - 08/24/13 03:04 AM

Hey Guys,,thanks for the great ideas! I used a SSBC adj. Prop. valve/distribution block combo. It also has the G.M. style pressure activated sensor/switch that I am going to try and use instead of the mechanical switch on the brake arm. It's fairly compact, mounts in the stock location. I also bought the Eastwood Pro-Grade flaring tool and it made a perfect 45 deg. flare in 30 seconds in stainless steel!

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Posted By: edco440

Re: Which Proportioning valve for 4 Wheel Discs? - 08/24/13 03:13 AM

Posted By: edco440

Re: Which Proportioning valve for 4 Wheel Discs? - 08/24/13 03:16 AM

#3 I'll probably switch the Drivers side Frnt line to the end port, I have excess length on this line to work with. The other Front port is shown in the pic and the rear line is at the rear with plenty of clearance,(not shown in the pic), the Master lines are at the top.

I have decent success with sealing Stainless by tightening the flare, loosen it, repeat 5-6 times. This should wear mate the SS and get it to seal.

Attached picture 7825273-004.JPG

Posted By: dangina

Re: Which Proportioning valve for 4 Wheel Discs? - 08/24/13 04:36 AM

Quote:

Quote:

I as wondering if you just go from the rear brakes-->wilwood adjustable knob--->master cylinder

and for the front brakes just use a "Tee" to the front brakes to get rid of the propotioning valve altogether. I'm makining my own brake lines, I also bought the mastercool hydraulic brake line tool and its the cats meow

Yes, this is what I do on all my 4 wheel disc applications, with no issues, no factory distribution blocks, or gutted PV's,...results in a cleaner line organization in the engine compartment, less connections, less potential for leaks/issues

Mike

sweet thanks for replying, wasn't sure if this was the way to go