Motorcycle Repair: Hydraulic clutch bleeding/filling, honda shadow 750, v65 magna

Question
Chris - Maybe you can help me.  I've recently bought a Honda sabre (85) and found that it was leaking brake fluid out of the clucth master cyclinder(it takes dot 3) So I emptied the system, cleand out the piston and cups and reinstalled everything. It was frustrating to build pressure up again in the system, but after a LONG time of pumping a way and bleeding air bubbles I got pressure.  I tried to help a friend do the same with his Honda Shadow 750 (1984) whcih had a lot of air in the system, but we could not get pressure to build up.  We tried taking the hose off of the cylinder and squirting dot3 in there with an oil can, and it filledd up the clutch chamber no problem with clean fluid comming out of the bleed valve.  We capped the system, bleed a little more, no bubblees come out but absoulutely no pressure either.  Any ideas?

Answer
Hi Dan.
 Bleeding brakes, as you know, is not a complicated thing and it works to get air bubbles out of the line.

But, here's the part they don't tell you;

Some bikes have an additional problem with both the clutch and front brakes, including my own on my V65 Magna.  The problem stems from the configuration of the master cylinder, 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 it 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 you should not need more than 2-3 times to get the system working correctly.

Good luck.
FALCON