Topic: 71 CB500 Master Cylinder aggrevation

[Goofaroo]

It is always the little things that can drive you out of your mind and waste a good portion of your time. I have the master cylinder in stripped down and all I need to do is pull the circlip and take the internals out. I even managed to get the boot off without tearing it. After cleaning the 40 years of crud off of the circlip and the bore I have full access to the clip. The problem is that the holes in the clip are just barely (and I mean just barely) visible. Obviously this has proven to be a challenge in removing the clip. I have so tried grinding and bending an awl down to the point I could grab the ring with no luck. I'm still working on it but any ideas might same my family from a few choice words. A 15 minute clean and replace routine has so far turned into an hour long ordeal with no fresh ides to throw at it.

[Mainerider]

save yourself some incredible aggravation and buy Motion Pro's version of Honda's MBC snap ring pliers.About $35 with shipping but worth every penny when it comes to removing or installing the piston retaining internal circlip. And no  you can't get a similar  one at AutoZone for $8  It is a task-specific tool. I can tell you from experience that you will have the clip on and off in about 8 seconds flat using these.


http://www.motionpro.com/motorcycle/partno/08-0279

[Goofaroo]

I finally managed to get the clip out. Then I tried to pull the shaft out with no luck so I put the cap back on and hit it with about 120 lbs. of air pressure and still nothing. It moves freely in the bore but refuses to pop out even with the clip removed. Time for the kids to put on some earmuffs.

[ksmith0034]

+1 million on buying some good pliers.  I bought the cheap HF ones and they SUCK!!!  But since I bought a rebuild kit I didn't need to keep the original circlip.  I used an old pointy tool that looks kind of like a dental tool on steroids (for auto body work) and just torqued it out of there.  The rest was cake!

[Goofaroo]

Here is my nemesis.  It looks innocent enough.

[Mainerider]

I finally managed to get the clip out. Then I tried to pull the shaft out with no luck so I put the cap back on and hit it with about 120 lbs. of air pressure and still nothing. It moves freely in the bore but refuses to pop out even with the clip removed. Time for the kids to put on some earmuffs.

Sorry, my friend; as bad as getting the C clip off was, wait until you go to reinstall it.  5x more aggravating because the plunger is in the way. Is the washer below the clip also out now?  You shouldnt even need the air to remove piston componenets.  Try "punching"  a screwdriver or similar through the banjo bolt hole; it should push the piston out through the other end.

[ksmith0034]

When you put the new circlip in, use a deep well socket to gently tap it down into place.  I just did this last week and that made it EASY to put the clip back in!

[Goofaroo]

I was hesitant to run a small drift through from the brake hose side but I guess I'll give it a try. As for another ring or collar behind the clip I have no idea what else lurks in there but nothing has fallen out.

[Goofaroo]

Pounding on it from the hose side didn't help. I have given it some pretty heavy whacks and it is like hitting an anvil. I looked at an exploded view of the entire assembly and there is a washer shown behind the circlip. That must be what's holding up my progress but I find it hard to imagine that it is that firmly attached to the cylinder wall. I've got it soaking in some PB Blaster and beer in hand. I'm going to try to scrape around it's perimeter with a pick and see if I can free the washer and the plunger from Satan's grasp.

[ksmith0034]

Is the washer catching in the circlip groove?

[Goofaroo]

I had the same but I can't tell. Looking down in there it just looks like a shoulder. I find it hard to believe that the washer is catching enough of an edge that it is causing this but at this point I haven't ruled out anything. A little more time to let it soak and I'm headed back into battle.

[Mainerider]

You said initially that this was a routine cleaning so I assume it was working reasonably well before. If that is the case, then something is definitely holding it in.  I'm not familiar with your specific MBC but there should be just the C clip and then the washer retaining the piston assembly.  If the C clip is out but the washer has not fallen out freely, perhaps it is rusted solidly in place.  Can you see rust in the recess where the washer rides?  Better yet, do you see the washer itself?  BTW, how long since the last teardown (that you know of)?

[Goofaroo]

Actually by "routine" I meant routine for taking a bike that has sat for god knows how long and is new to me and trying undo years of neglect. I have started this bike but never ridden it. 
The good news is that after I had a beer and a couple of sandwiches, I went out there and armed with new found determination gave it a couple of whacks and the plunger popped out. The washer was pretty corroded but it cleaned up okay. The bore looks great, rubber is good and all is well. Thanks for all the ideas and replies.