brake/clutch hard line diameter differences?

[tyama]

Hiya, I am replacing the clutch hydraulics on my fj40 & i picked up a section of 3/16" hard line. I noticed that the factory hard line is 1/4". Anyone know if it makes any difference in pedal feel? I know that the smaller diameter should require more pressure as it moves less fluid, but it's only about a foot or so. I figured it should not really make a difference.

what say you guys?

Thanks! ty


p.s. any difference in using 1/4" vs 3/16" for brake lines?

 

[diogenese]

I can only see a problem with getting fittings that will fit the master and slave and suit the size of the pipe. Similarly for using 1/4 for brakes the pipe won't fit the tube nuts.

 

[Fast Eddy]

With the tiny volume of fluid that's moving back and forth it can't possibly make a difference, but why not just get the correct line?

 

[73FJ40]

The diameter of the hard line has no impact on pressure or the amount of fluid moved. X amount of travel on the clutch pedal will result in Y amount of travel on the slave cylinder, regardless of the size of the line.

Diogenese is right. Get the tubing that matches the fittings that connect to your M/C and flex hose.

 

[tyama]

Thanks! IIRC, both types of line from Napa auto had the 10mm metric male on either end so it would work either way. I was just thinking that a smaller diameter line would require more foot effort to move the slave piston the same distance.

best, ty

 

[73FJ40]

If the clutch M/C had a larger bore, that would mean harder pedal push but shorter throw. For what it's worth, the hard line could be 1/2" diameter tubing and it would have no effect on pedal effort.

Also note, there's another thread going on now (see below) that suggests that some early 70's had M11 fittings, which might be linked to the 1/4" tubing you mentioned.


Unobtainium (page 41, post 819)

 

[tyama]

thanks again. Yeah it does have m11. I forgot to mention I'm swapping the whole system out for a 75 & up clutch master & slave so it'll match what I have on the pig and I can just get parts for one setup. I now have to get a clutch/brake flex line with 10mm fittings as the old flex line is much too big. anyone need a used 11mm line for a spare?

best, ty