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MG Midget and Sprite Technical - Does the pipe sixe affect the clutch movement?

Good morning Gentlemen
Just a thought. As the title say, will fitting of a 3/16 in stead of the standard 1/4" pipe between the clutch master and slave affect the clutch movement when engaged?
What I suspect is, that the larger pipe can absorb more fluid than a 3/16" pipe and I suspect the throw to be increased with the smaller diameter pipe.
But I'm not sure if is like that......
Jan
Jan Kruber

No Jan. The pipe size is irrelevant. The movement at the slave is dependant on how much fluid is moved by the master cylinder. The connecting pipework is already full of hydraulic fluid (assuming no air bubbles) so whatever gets pushed in one end is displaced out of the other.
A very thin pipe might make the pedal harder to press because of the restriction,but the movement and distance of the slave will still be the same.
GuyW

There may be an issue with the speed the clutch engages if the flow of fluid back to the master cylinder is restricted.

I’m assuming they fitted that size pipe for a good reason.
Dave O'Neill 2

Guy
What I have considered too, but why did they fit 1/4" ?
As you state, Dave, "I’m assuming they fitted that size pipe for a good reason"
Thats why I'm alert, because all other pipework is 3/16"
Jan Kruber

Jan,
It doesn't effect the clutch movement - meaning the pedal stroke and clutch throw will be the same. - which is what you asked about.
But a narrow pipe will provide more resistance to the flow rate through it which will make the pedal seem harder to press.

With much longer pipe runs on braking systems, the relatively small amount of fluid actually being moved through the pipes is of less importance. What is happening with a braking system is the transfer of the pressure rather than the fluid movement which is important. Though they are of course related.
GuyW

As Guy says the movement of the slave is governed by the bore size of the master and slave cylinder.
Bob Beaumont

Most important is, that the movement of the clutch will not increase. A harder pedal is no problem, but maybe the new concentric slave will compensate for the narrow pipe, since there a fewer moving parts / joints.
I will do a bench test with hydraulics fitted to see the full movement of the clutch before installing the lump into the car.
Jan Kruber

This thread was discussed between 06/03/2019 and 07/03/2019

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