Subaru Enthusiasts Car Club of the Sierras - View Single Post

ryan4601 · 2010-02-23, 11:05 AM

Scott is right on with his description, although I think it is for 03+ but don't quote me on that. Check valve is in place so that no matter if you dump the clutch or let it out slowly fluid will flow out of the clutch actuator back into the master cylinder at a consistent rate. (flow in disengages the clutch, flow out engages it). I didn't notice a life changing difference, but i feel that it made a positive change and it cleans up the system up quite a bit. It is also recommended by exedy for multi plate clutch systems. Many of the members on the BMW forums i looked at swear that the removal of the check valve is one of the best things they ever did to their cars.

According to the sources I found on NASIOC and IWSTI the big silver piece attached to the bottom of the clutch master cylinder and the "slave cylinder" attached to the clutch actuator are involved. The actual check valve is made up of a few springs and plastic pieces located in the clutch slave cylinder, but the silver piece also has some involvement according to others. I just replaced the silver piece with a plug and removed the clutch slave cylinder all together. If you are interested in doing this mod, there are good step by step instructions on IWSTI.com, search 'clutch delay valve'.
Ryan

2010-02-23, 11:05 AM	#17
ryan4601 EJ22 Join Date: Feb 2004 Posts: 244 Car: 2004 wrx	Scott is right on with his description, although I think it is for 03+ but don't quote me on that. Check valve is in place so that no matter if you dump the clutch or let it out slowly fluid will flow out of the clutch actuator back into the master cylinder at a consistent rate. (flow in disengages the clutch, flow out engages it). I didn't notice a life changing difference, but i feel that it made a positive change and it cleans up the system up quite a bit. It is also recommended by exedy for multi plate clutch systems. Many of the members on the BMW forums i looked at swear that the removal of the check valve is one of the best things they ever did to their cars. According to the sources I found on NASIOC and IWSTI the big silver piece attached to the bottom of the clutch master cylinder and the "slave cylinder" attached to the clutch actuator are involved. The actual check valve is made up of a few springs and plastic pieces located in the clutch slave cylinder, but the silver piece also has some involvement according to others. I just replaced the silver piece with a plug and removed the clutch slave cylinder all together. If you are interested in doing this mod, there are good step by step instructions on IWSTI.com, search 'clutch delay valve'. Ryan Last edited by ryan4601; 2010-02-23 at 11:27 AM.