[Spridgets] 3/4" v. 7/8" MC

[Kitterer Bob]

For my two cents I think there are several errors here.  Assuming the  
same size brake line, which for us is normal, the 7/8 piston is  
attempting to push more fluid through the line for an equal piston  
travel which I think means that the line pressure goes up - - - Frank  
locking up his rear wheels ? ? ?  The pedal pressure probably goes up  
for the same reason.  The salve piston is mechanically limited so its  
travel can not change, it just has more pressure being applied.


Bob Kitterer

1960 Austin Healey Sprite (Mk IV in disguise)
1966 Austin Healey Sprite Mk III (Trevor) - still in boxes
2000 Miata Special Edition



On Aug 13, 2008, at 3:26 PM, Billy Zoom wrote:

> I'm taking a survey.
> How many of you believe this to be true?
>> The area of the 7/8" piston is about 36% greater than the area of  
>> the 3/4"
>> piston. This means that the pedal effort required for clutch and  
>> brake
>> operation is 36% higher with the larger cylinder. It also means  
>> that clutch
>> slave piston travel is 36% greater. The increase in required pedal  
>> effort
>> constitutes a significant safety and drivability issue, and the  
>> increased
>> slave piston travel can cause mechanical problems with the clutch  
>> linkage.
>> www.brakecylinder.com/spridgetbrakes.htm