clutch master & slave bleeding question, how did GM do it ?
05-31-2013, 01:24 PM
#1
clutch master & slave bleeding question, how did GM do it ? been reading the clutch horror stories and i am curious about a few things.
1) after the transmission gets removed from the engine, do you also need to support the rear of the motor?
2) does anyone know the distance how far the pressure plate fingers need to be depressed in order to properly release the clutch? I assume this distance would vary for different make clutches? does this info come with a new clutch? trying to understand what causes clutch pedal and release problems with various new clutch installs, most of which are not exact oem replacements.
3) i can't fathom union auto workers on the gm assembly line working in tandem bleeding a clutch setup for every car built making a mess. Isn't it the purpose of the quick disconnect line from the clutch master cylinder to allow you to fully bleed it on a bench then install? Then the only concern is air in the slave in the transmission so how is that handled? Wouldn't that also be bled by the supplier or prior to being installed in the transmission on the assembly line? When you got a new f-body, there was not a line of brake fluid inside the bellhousing or down the outside of it from having been bled was there? So my thought is how did they do it to allow install of the transmission, plug in the quick disconnect, and done?
You could not fully fill the slave with fluid and bleed it because then it would be locked fully out and not let you install the trans. so what if you did fill and bleed it, then with bleeder open compressed the slave either all the way or a preset known amount then closed the bleeder? this would ensure no air in the slave and allow you install the trans. then when you connect the quick disconnect line, clutch fluid would fill the slave from the master the remaining amount since the spring will have pushed the slave cylinder out to meet the pressure plate, but that extra space in the slave would be a void not air.
1) after the transmission gets removed from the engine, do you also need to support the rear of the motor?
2) does anyone know the distance how far the pressure plate fingers need to be depressed in order to properly release the clutch? I assume this distance would vary for different make clutches? does this info come with a new clutch? trying to understand what causes clutch pedal and release problems with various new clutch installs, most of which are not exact oem replacements.
3) i can't fathom union auto workers on the gm assembly line working in tandem bleeding a clutch setup for every car built making a mess. Isn't it the purpose of the quick disconnect line from the clutch master cylinder to allow you to fully bleed it on a bench then install? Then the only concern is air in the slave in the transmission so how is that handled? Wouldn't that also be bled by the supplier or prior to being installed in the transmission on the assembly line? When you got a new f-body, there was not a line of brake fluid inside the bellhousing or down the outside of it from having been bled was there? So my thought is how did they do it to allow install of the transmission, plug in the quick disconnect, and done?
You could not fully fill the slave with fluid and bleed it because then it would be locked fully out and not let you install the trans. so what if you did fill and bleed it, then with bleeder open compressed the slave either all the way or a preset known amount then closed the bleeder? this would ensure no air in the slave and allow you install the trans. then when you connect the quick disconnect line, clutch fluid would fill the slave from the master the remaining amount since the spring will have pushed the slave cylinder out to meet the pressure plate, but that extra space in the slave would be a void not air.
05-31-2013, 02:15 PM
#2
4) other thing i wanted to ask which is related to #2 above, is about matching master cylinder and slave combination with a given clutch. For example on my 2002 which is original- it has whatever part # master cylinder and slave. From what i could measure and find on the web, the master has about an inch or 26mm of piston travel when you push the clutch down. I found on the web that the master cylinder bore is 1.9 cm, don't know if that's accurate. With the oem slave I don't know what the bore area of that is but if you did then you would know the maximum travel potential of the slave and what your pedal effort would be. this would be hydraulics 101. with everything oem, it works and clutch engages around 1/2 way off the floor and has no problem disengaging under normal driving conditions. so...
the ls7 clutch package is recommended here, but what clutch master cylinder was used with it? is it the same size as what was is in my 2002? because if it isn't, and i'm sure the part numbers are different, then you have to account for that and verify that what slave throw out distance you do get is sufficient to operate the LS7 pressure plate right? how much distance to the fingers on the LS7 pressure plate require being depressed to operate properly? I think I basically asked this in #2, my concern is say I get an aftermarket clutch once you start changing out slave cylinders (or even if you don't) then don't know need to verify the amount of throw the slave gets from a clutch pedal being depressed is sufficient to operate the pressure plate? Because it seems like everyone gets a new clutch, different than oem, but then has problems and the solution is to get "an adjustable master cylinder" which is also has a larger bore which means it will give you more slave throw out distance. but if this is the case then it's not that the oem master/slave is the problem of too short a throw out distance, it's the new clutch pressure plate not operating the same as oem which really means it's not a direct fit your the application or it requires other modifications to work, no ?
the ls7 clutch package is recommended here, but what clutch master cylinder was used with it? is it the same size as what was is in my 2002? because if it isn't, and i'm sure the part numbers are different, then you have to account for that and verify that what slave throw out distance you do get is sufficient to operate the LS7 pressure plate right? how much distance to the fingers on the LS7 pressure plate require being depressed to operate properly? I think I basically asked this in #2, my concern is say I get an aftermarket clutch once you start changing out slave cylinders (or even if you don't) then don't know need to verify the amount of throw the slave gets from a clutch pedal being depressed is sufficient to operate the pressure plate? Because it seems like everyone gets a new clutch, different than oem, but then has problems and the solution is to get "an adjustable master cylinder" which is also has a larger bore which means it will give you more slave throw out distance. but if this is the case then it's not that the oem master/slave is the problem of too short a throw out distance, it's the new clutch pressure plate not operating the same as oem which really means it's not a direct fit your the application or it requires other modifications to work, no ?
02-14-2015, 11:31 AM
#6
1. you can use a floor jack under engine pan to support motor (I use a folded towel to cushion it). some people just let motor hang but I find jack helps to move motor up/down while stabbing the tranny. helps align engine & trans
2. you measure "stack height" of the clutch assembly to determine if a shim is needed behind the slave. some aftermarket clutches come with them.
contact a company like Monster Clutch with ?'s
2. you measure "stack height" of the clutch assembly to determine if a shim is needed behind the slave. some aftermarket clutches come with them.
contact a company like Monster Clutch with ?'s
