SMG clutch bleed procedure 21532229082

On E36 M3 models with SMG transmission.  When replacing smg pump or servicing SMG system which could introduce air into system it is important to bleed clutch slave cylinder manually before performing software bleeding procedure.


1-Remove smg clutch slave cylinder from bell housing(do not remove or loosen fluid line, keep fluid line connected to slave cylinder at all times)

2-Compress slave cylinder push rod into clutch slave cylinder and hold it in position.(Special tool available bmw 21 5 030)

3-Fill main reservoir with Hydraulic fluid, Loosen bleeder screw on secondary reservoir and wait until fluid starts to escape from bleeder screw. Close bleeder screw and fill main reservoir.

4-Mount special tool to pressurize reservoir and pressurize to 2.5bar/36psi.(BMW or aftermarket tool will work but should be used only for SMG)

BMW tool #

  • 21 5 010(reservoir cap adaptor)
  • 17 0 002(pressure pump)

Warning!  Any tools(Cap adaptor/hoses) used for this bleeding procedure that contacts hydraulic fluid should not be used for other systems like brakes etc.  The fluid used in SMG system will damage any seal that is not designed to work with hydraulic fluid and lead to system damage or complete failure.

5-Connect(tool 21 5 020) bleeder hose and container to clutch slave bleeder screw. hold clutch slave in position where bleed screw is highest point and open bleeder screw. 

6-When bubble-free hydraulic fluid emerges, Start allowing push rod to extend slightly and return back to compressed position.

Warning! Do not allow slave cylinder push rod to be release from compression at any time. doing so will allow push rod to be ejected forcibly from clutch slave cylinder.

7-If no air bubbles escape, close bleeder glove.

Note: At this point Main reservoir might have to be topped up with fluid and re-pressurized to 2.5bar/36psi.

8-De-presurize and remove special tools from main reservoir.

9-Slowly allow slave cylinder push rod to extend and remove special tool.

10-Re-install slave cylinder back onto bell housing.

11-Check main reservoir fluid level is full.

12-Perform bleeding procedure with diagnostic tool.

Note: Monitor main reservoir for fluid top up as residual air will be pumped into reservoir during diagnostic bleeding.


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