simple clutch bleed question

[1fast97gsx]

Does it matter where the adjustment rod on the master cylinder is set when you are bleeding the clutch? I have it backed all the way out and can't seem to get all the air out.

 

[fastezz]

same here same exact situation, im taking these steps tommorow though http://www.dsmtuners.com/forums/showthread.php?t=60319 I was also using brake fluid that is kinda old.
Ryan

 

[1fast97gsx]

yea I read that too and I know the actual process, but I've never seen a write up that said if the pushrod on the master cylinder needs to be at any certain spot. Also I read it's a good idea to bleed just the master first, then do the line and the slave. I will be doing this tomorrow.

 

[1fast97gsx]

I just blead it some more with the master cylinder rod screwed into the pedal bracket about 1/2". I had the cruise cut switch backed out 90% of the way. Is this correct?

 

[fastezz]

I have no idea, I have a worn down pedal assembly, I bled it about when it was maxed out and its not going in gear, its stiff as hell though like its suppose to be.
Ryan

 

[1fast97gsx]

where did you have the pushrod set on the master when you bled it? How long did it take you to get all the air out?

 

[fastezz]

I had the pushrod maxed out adjusted as long as it can go, it didnt take to long to get all the air bubbles out.
Ryan

 

[Morphius]

I have it backed all the way out and can't seem to get all the air out.

Backed out? Do you mean the pushrod is nearly screwed out of the clevis? If this is the case, it would explain why you can't get the air out.

The master cylinder is comprised of a piston and compenstion valve. The compensation port is closed off by the compensation valve in the first 5mm of pedal travel. It blocks off the fluid in bore of the master cylinder (M/C) from the fluid in the reservoir. By adjusting the input rod of the M/C nearly all the way out of the clevis that attaches to the pedal blade, the pedal could be 'preloaded' causing the M/C to close the comp port.

The result is that when you release the clutch, the hydraulic system can't compensate for tolerances in the system (ie clutch wear) The end result is, each time you push the pedal, you are simply pushing a 'column of fluid' that is sealed between the M/C and the slave cylinder. It can't release fluid in or out of the reservior. Each time you stroke the pedal, you aren't drawing in fresh fluid on the return stroke when you bleed it. And you won't be pushing any fluid out, moving the air closer to the slave cylinder.

I'd suggest keeping the input rod in a centered position in the clevis. Bleed the system. Then adjust the pedal height per the instructions in your service manual, by adjusting the input rod in the clevis.

 

[1fast97gsx]

alright, thank you that helped a lot. I blead it with it pretty much in the middle and once I was done I then backed it out a little bit out of the clevis. I think I got it right now.

 

[1fast97gsx]

just to follow up on this ...

The clutch feels fine on warm days or if I park it in a heated garage. If I leave the car outside in the cold for a while and get in and start it the clutch will feel really soft for the first 1/2 or so still and then stiffen up. I blead the system again today with the rod right in the middle, but no air came out so I think I got it all last time. Once I started driving it the pedal stiffened up again to how it should feel, but I have a feeling if I park it outside overnight it won't feel right again in the morning. What would cause this!?

 

[Defiant]

http://www.roadraceengineering.com/clutchandflywheeltech.htm

 

[1fast97gsx]

Yea I read that link from rre a few times but still can't quite figure out my problem. My flywheel step is correct, no more air is in the lines, and I think I adjusted it properly. All I can think is that I need to try the longer slave cylinder rod. Installing a longer slave rod will give me more room for adjustment on the master cylinder rod correct?