Brake Pedal/Master Cyliner Assembly

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  #1  
Old 11-16-04, 10:42 PM
nosubstitute959
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Brake Pedal/Master Cyliner Assembly

I'm working with a team to build a small off-road vehicle. I'm responsible for the braking system and I have been trying to learn how everything functions and could use some help. Anyway.....one of the rules says the car has to have 2 independent hydraulic systems operated by one pedal. My understanding of this is that there should be a fork in the pedal where each branch goes into a separate single-piston master cylinder. Am I correct? Now I need to place those cylinders a small distance away from the pedal. Is this uncommon? If no, then what ways are there to transmit the pedal force to the cylinders?

I know this isn't even clear to me as I read over it, so I expect questions asking me to clarify what I mean.
 
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  #2  
Old 11-17-04, 01:33 AM
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Could you use a

regular master cylinder from a car? My understanding is that it already has two independant braking systems. This may make your life a lot simpler.

I'm not sure about the rest of the system though, hopefully you'll get more suggestions.
 
  #3  
Old 11-17-04, 03:24 AM
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What your looking for is common to race cars. Two seperate systems with a brake "bias" control to adjust more or less force on each system.

Any place that sells race car parts would have every thing that you need.
 
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Old 11-17-04, 09:16 AM
nosubstitute959
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I don't understand how there could be a "bias" when you're using the same pedal force. Unless I pick different bores for both cylinders, how could the pressure in each line be different. Could you please explain that briefly?
 
  #5  
Old 11-17-04, 09:35 AM
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They have different systems, one I believe adjusting the rods creates different pressures.
 
  #6  
Old 11-17-04, 11:12 AM
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There is also a setup where the two masters are seperate and both connect to the pedal assy with a "U" shaped bracket.

Then the rear line will have an ajustable "bias" valve to regulate rear pressure. This will be in reach of the driver to adjust as needed during a race. It will have a knob or lever to adjust it.
 
  #7  
Old 11-20-04, 08:40 AM
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Originally Posted by nosubstitute959
I don't understand how there could be a "bias" when you're using the same pedal force. Unless I pick different bores for both cylinders, how could the pressure in each line be different. Could you please explain that briefly?
The problem is exactly that, they will have the same pressures. But you will want to have the pressure going to the rear wheels to be less than the pressure going to the front wheels. Otherwise the rear wheels will lock up before the fronts and you wont achieve maximum braking power and control. The amount af bias will vary by vehicle and driving conditions. And as toyotaman said, the control knob is mounted within arms reach so the driver can adjust as driving conditions change.
 
  #8  
Old 11-20-04, 10:29 AM
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Sometimes that is exactly what is done
Unless I pick different bores for both cylinders
Then it is fine tuned with a bias valve installed in the rear line.
 
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Old 11-20-04, 01:50 PM
nosubstitute959
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I see. We'll I try to see what exactly I need and I'm sure I'll be asking you guys more questions when it's time to select the parts.
 
  #10  
Old 11-21-04, 10:13 PM
nosubstitute959
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Are there any online sites that sell brake parts that you don't have to select by car brand? Does anyone of you know of a certain brand or site that sells cheaper than the rest? How about catalogs of calipers, brake lines, single piston master cylinders, boots, push-rods, pedal assemblies...etc? How can I get catalogs to look at? I'd appreciate that info.
 
  #11  
Old 11-21-04, 10:16 PM
nosubstitute959
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Also, what's meant by straight-bore master cylinders? Is that the same thing as single-piston? Or does that mean no power assist?
 
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