# Adjustable Proportioning Valve for Mk1 (question)



## hoooboy (Jul 7, 2006)

I have :
G60 Front Disk Brake
Rear Scirocco Disk Brake
Dont know what's the brake booster but I have a 21mm master cylinder!
Everything is okay but I need to put proportioning valve! I don't have this on my car!!!
I want to buy wilwood adjustable prop. valve!
I need one or two???
Does it have a way to put just one prop. valve??
If yes...is it good or I should buy two prop. valves???
If I have to buy 2 prop. valves... 
I probably should buy wilwood lever because those with the knob will be a little difficult to adjust???
Please help me!


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## spitpilot (Feb 14, 2000)

*Re: Adjustable Proportioning Valve for Mk1 (hoooboy)*

The ol VW';s I've worked on all had only one brake line goin back to rear brakes...and only one proportioning valve in it!


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## Anson86-8v (Feb 17, 2003)

*Re: Adjustable Proportioning Valve for Mk1 (hoooboy)*

A proportioning valve is nothing more than a variable orifice which means it can't control line pressure, only flow rate. A dual master cylinder setup with an adjustable balance bar is the only way I know of to adjust line pressures properly.


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## hoooboy (Jul 7, 2006)

*Re: Adjustable Proportioning Valve for Mk1 (Anson86-8v)*

sooo...


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## atarasi (Nov 26, 2004)

*Re: Adjustable Proportioning Valve for Mk1 (Anson86-8v)*

Here's some good reading...
http://www.babcox.com/editorial/bf/bf50014.htm
Sounds like a proportioning valve is only going to prevent rear lock up, not regulate pressure between the front and rear if I glanced at that article slow enough!


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## hoooboy (Jul 7, 2006)

*Re: Adjustable Proportioning Valve for Mk1 (atarasi)*

I crashed my car because the rear wheels locks...so this is the reason why I want proportioning valves...
So I want to know If I had to buy one or two adjustable prop. valves!!


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## atarasi (Nov 26, 2004)

*Re: Adjustable Proportioning Valve for Mk1 (hoooboy)*


_Quote, originally posted by *hoooboy* »_
So I want to know If I had to buy one or two adjustable prop. valves!!


I would direct your question to Wilwood. Are there two lines going in to the Wilwood valve and two out?


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## hoooboy (Jul 7, 2006)

*Re: Adjustable Proportioning Valve for Mk1 (atarasi)*

just one inlet and outlet


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## atarasi (Nov 26, 2004)

*Re: Adjustable Proportioning Valve for Mk1 (hoooboy)*

VWs have two diagonal circuits so you're going to need two anyway. Even with drums in the rear, one can lock up and not the other.


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## o2bad455 (Aug 22, 2003)

*Re: Adjustable Proportioning Valve for Mk1 (atarasi)*

For racing, especially with the dial type adjustable brake proportioning valve, we often switch the stock dual-diagonal to a front/rear split system (by moving both front brake lines to one end of the MC, and running just one rear line from the other end of the MC). Then both rear brakes can be run from a T fitting with just one proportioning valve. When doing this, you must watch for MC capacity since one circuit (usually the fronts) may need more capacity than the current MC might provide. RACE ONLY!
If this is a street car and you want to keep the inherent safety feature of a dual diagonal system, the only way that I've seen it done with adjustable proportioning valves is to use 2 of the lever type valves since they can be adjusted to match fairly easily. I think the Tilton lever type (TIL-90-1003) comes with 10mmx1mm fittings, so you wouldn't have to worry about NPT to IFF adapters when using stock VW brake tube fittings. 


_Modified by o2bad455 at 12:38 PM 1-17-2008_


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