6 replies to this topic

[driftz]

Quick clutch bleeding question.

 

Do you bleed the clutch after setting the mechanical freeplay on the bolt and big nut, or before. My thinking being, that if the mechanical freeplay is all backed off when bleeding, you can get the full motion of the hydraulics, without them being impeded by the stoppers. However, with the stopper set first, you have a finite amount of play to work within to get the air out.

 

thoughts?

[littlewimp]

i dont think that the travel would make any difference to the bleeding operation because you will still push the same ammount of fluid through the system via the master cylinder.

[sledgehammer]

as above - you are just trying to remove the air when bleeding - not move the arm

 

some (non automotive) hydraulic set up's will need the piston / ram moving to expose the bleed nipple channel (I work on hydraulic machinery)

 

but on most hyd clutches I have worked on - no movement is necessary & bleed is usually uppermost in the cylinder

 

but bleed before adjustment anyway

 

 

 

edit one place on a mini where the bleed is at the bottom of the cylinder - is on the rear brake cylinders

 

they can sometimes can be a pig if the pistons are out a bit - they can trap air

Edited by sledgehammer, 13 November 2015 - 10:27 PM.

[peter-b]

If you're doing it on your own the free play helps. You pump up as much as possible, wait a minute, then push the slave cylinder in. Pushes air up and out M/C. Then adjust free play.

[driftz]

as above - you are just trying to remove the air when bleeding - not move the arm

 

some (non automotive) hydraulic set up's will need the piston / ram moving to expose the bleed nipple channel (I work on hydraulic machinery)

 

but on most hyd clutches I have worked on - no movement is necessary & bleed is usually uppermost in the cylinder

 

but bleed before adjustment anyway

 

 

 

edit one place on a mini where the bleed is at the bottom of the cylinder - is on the rear brake cylinders

 

they can sometimes can be a pig if the pistons are out a bit - they can trap air

 

This makes me think that the most efficient way of bleeding would be to remove the slave push rod from the clutch arm and pull it out to its furthest point of its extension. Then just bleed as if there was no moving parts in the slave. This might make less places for air to hide in the slave? hmm...

[Blatherskite]

as above - you are just trying to remove the air when bleeding - not move the arm
 
some (non automotive) hydraulic set up's will need the piston / ram moving to expose the bleed nipple channel (I work on hydraulic machinery)
 
but on most hyd clutches I have worked on - no movement is necessary & bleed is usually uppermost in the cylinder
 
but bleed before adjustment anyway
 
 
 
edit one place on a mini where the bleed is at the bottom of the cylinder - is on the rear brake cylinders
 
they can sometimes can be a pig if the pistons are out a bit - they can trap air

 
This makes me think that the most efficient way of bleeding would be to remove the slave push rod from the clutch arm and pull it out to its furthest point of its extension. Then just bleed as if there was no moving parts in the slave. This might make less places for air to hide in the slave? hmm...

Very easy to fire out the slave piston doing that. Then start all over again...

[driftz]

 

 

as above - you are just trying to remove the air when bleeding - not move the arm
 
some (non automotive) hydraulic set up's will need the piston / ram moving to expose the bleed nipple channel (I work on hydraulic machinery)
 
but on most hyd clutches I have worked on - no movement is necessary & bleed is usually uppermost in the cylinder
 
but bleed before adjustment anyway
 
 
 
edit one place on a mini where the bleed is at the bottom of the cylinder - is on the rear brake cylinders
 
they can sometimes can be a pig if the pistons are out a bit - they can trap air

 
This makes me think that the most efficient way of bleeding would be to remove the slave push rod from the clutch arm and pull it out to its furthest point of its extension. Then just bleed as if there was no moving parts in the slave. This might make less places for air to hide in the slave? hmm...

Very easy to fire out the slave piston doing that. Then start all over again...

 

 

on my slave at least there is a locking circlip that keeps it from popping out.