Does anyone have a picture or know exactly which connections are made to the 4040 prop valve? I,m putting one in my 92 accord because of rear disc swap. There is no non abs prop valve.

 

ok not to thread jack..sorry op...but i thought proportioning valve were for rear drum brakes. and metering valves were for front disc brakes,
i asked my instructor what everyone was talking about when they did a rear disc swap and added a prop valve and he looked at me like i was the stupid kid he had seen in years...please clear this up for me why is the prop valve needed in the rear???????????
once again im sorry to thread jack but its bothering me.

 

here.
http://www.crxcommunity.com/viewtopic.php?f=3&t=26420\


freeagent, sounds like a difference of technical semantics. for a honda, its still a prop valve regardless of drums or disc.

btw, abs systems dont have prop valves. the system itself does the proportioning and is in place of the prop valve. just fyi.

 

thanks man thats what my teacher told me he siad hondas just might be te black sheeps or somethin..
thanks for clearin that up for me ...and once again sorry to thread jack

 

Thank you Tyson you made my day!

 

Ben, This belongs in the Accord forum. Not in the ef/crx forum. Sorry.
And by the way, I found a WORKING tranny.

 

I guess the link to other thread showing the 4040 connections was already posted above, however I wanted to quote some info I found online about brake metering and proportioning valves. I think many will find it very helpful and informative.
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Proportioning Valve FAQ
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What does a proportioning valve do?

A proportioning valve is used in the rear to decrease the rate of pressure rise to the drums relative to the pedal force as weight is shifted to the front during braking. This prevents the rear from locking up under hard braking conditions.
What are the symptoms of a bad proportioning valve?

If your prop valve has gone bad your rear wheels will lock up easily, especially on wet surfaces.

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What does a metering valve do?

A metering valve or "hold off valve" is used in the disc portion of a disc/drum system to hold off the application of the front discs slightly allowing the slower reacting rears to catch up. This provides rear stability on wet surfaces and reduces excessive pad wear.
What are the symptoms of a bad metering valve?

Your car will nose dive and the front pads will wear too fast.

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What does a residual valve do?

There are two different uses for residual valves. The 10 lb valve is used to hold a residual pressure to the drum brakes to give a higher firmer pedal. The 2 lb valve is used in the disc when the master cylinder is lower than the calipers to prevent back siphoning of the fluid from the master.
What are the symptoms of a bad residual valve?

The brakes will be very spongy and you will need to pump the pedal to get good brakes.

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What is a combination valve?

A combination valve incorporates metering and proportioning into one valve providing all necessary valving for disc/drum systems. See below

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Should I use an adjustable proportioning valve?

Not if you can help it. The adjustable valve will only provide the proportioning function and not the metering that is needed.

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VALVE TYPES & DESCRIPTIONS

Metering
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The metering or hold off valve is used in the brake system to better balance the front to rear brakes. The valve does not allow the pressure to rise at the front disc brakes until the pressure at the rear drums has risen sufficiently to overcome the brake shoe springs. At this point the valve opens to allow full pressure to build at the front brakes.

Proportioning
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The proportioning valve modulates the pressure to the rear brakes. The modulation is necessary to minimize rear wheel lock up found in heavy braking and to compensate for the differences in braking conditions in front disc / rear drum systems. As pressure is applied to the system full pressure is allowed to the rear drums up to a certain point. Beyond that point the pressure to the rear is reduced preventing rear brake lock up.

Residual
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There are two different residual valves. A ten pound residual valve will maintain a line pressure to the rear to keep the drum brake shoes out close to the drums giving a higher firmer pedal. Without a ten pound residual pressure to the rear you will experience a spongy pedal. A two pound residual valve is required whenever the master cylinder is lower than the calipers to prevent backflow of fluid from the calipers to the master.

Combination
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A combination valve incorporates metering and proportioning into one valve. These are available for disc/drum or drum/drum systems.

Adjustable Prop. Valve
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The adjustable proportioning valve is used when you have a special rear condition that requires higher or lower pressure than a normal condition. You sould always use a metering valve to the front when using the adjustable

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My opinion is there are so many variables from one setup to the next. Changing the brake disc sizes, pad friction material, tire and wheel size, rubber compounds, airflow to the brakes, shock damping, spring rates(front vs rear) and vehicle weight distribution, and so on, will all cause different effects on the brake system performance and response.

For example, if you increased the rate of your springs, I would expect less nose dive (weight transfer to the front) under braking and therefore, the back brakes could effectively receive more braking force without locking up the rear wheels. I think that a fixed design oem valve like a 4030 or 4040 are not able to adjust or compensate for such changes.

In a case such as this, an adjustable valve would allow the driver to tune the brake proportioning for maximum braking for a cars particular setup. Later on, if you change other things on your setup, like spring rates, and shock tuning, or tire size or compound, then you can easily adjust the proportioning to maximize braking performance in response to those changes.

 

^^ i like this information.

the residual is a very important and largely unknown characteristic of even the stock prop valves and is why the 4040, 3030, 2017 numbers are hard to simply breakdown into a simple "proportion" or fraction, which is why its absolutely incorrect to call them "40/40" valves.