Motorcycle Repair: getting air out of the master cylinder & slave cyl, clutch master cylinder, clutch slave cylinder

Question
Hey Chris,

Have 1982 V45 Magna VF 750 that I am trying to restore, bought a new clutch master cylinder and a new clutch slave cylinder for the bike from a dealer who bought it from Honda.
I installed both new units but I cannot get the pressure to build up on the cylinders to release the clutch do you have any ideas on getting the air out?  I have done everything the manual has told me step by step but with no luck.

Thank You,

Judy Evans
mamawjke@netzero.net

Answer
Hi Judy.
 This is a common problem with all Magnas for both the clutch and front brakes, including my own.  The problem stems from the configuration of the master cylinder on this particular bike, which is that the connection to the hydraulic line at the master cylinder creates a pocket that air bubbles like to hide in (this is called a reverse trap) and the method for bleeding that section is a little tricky if you've never done this before.

 Here's the proceedure;

1) Bleed the clutch/brake line like normal.

2) Put a wrench on the banjo fitting and squeeze the lever.


3) (NOTE: Use a box end wrench for this) While holding the clutch/brake lever in, crack loose the fitting and reclose it quickly. Have a rag over the fitting connection that you are working on because it will spit at you as pressure expells the air and a little fluid.
IMPORTANT NOTE: Do not release pressure on the lever till the fitting is tightened back up or you will suck air back into the line.

4) Test the clutch/brake again.  If done correctly, you will have pressure near the beginning of the lever movement rather than at the end.

5) repeat as needed, but should not need more than 2-3 times.

Good luck.
FALCON