Rear brake M/cyl sticking

[Tx Bohemian]

I replaced the rear wheel bearings on my '99 standard which included pulling the brake pads apart and when I reassembled and attempted to pump up the brakes the pedal pushed down all the way one time and now there is no resistance when I try to pump them up, nor do I have rear brakes.
I suspect the M/cyl is stuck because before I bought this bike it sat up for over 2-1/2 years.  As I was driving it home I applied the rear brake and it wouldn't release completely(noticible drag).  As I was pulling over to see what I could do, it released and worked ever since, till now.

It seems I saw a post about a sticking master cylinder but I can't seem to find any.  (I'm not the best "search" person around)

Anyone know where I can find it or any information about this situation?

I called the local Honda place to see how much a rebuild kit or complete M/cyl is and the parts guy couldn't find any, he said we will have to piece it together.  Is there a place I can get a kit or comlete cyl?

[AussieValk]

I had trouble when I did mine also. The pistons in the caliper were sticking so I blew them out and cleaned them up for reuse. I should've replaced the seals as well but impatience and not having any meant they were checked, cleaned and reused as well. The problem was bleeding the air out of the line again. I did it the conventional way using the speedbleeder nipple and found that it used a hell of a lot of fluid to flush the air out. When you're pumping the pedal make sure it doesn't go down all the way to the stop. all the seals and parts are available from HDL but you have to buy individually.

[Ricky-D]

More that likely the crud that collects in the brake fluid reservoir has now been pumped down into the master cylinder and it is causing the cup to allow fluid to bypass making "no pedal". It's the same scenario with the pedal not returning to the stop position, except this is from the rear cup crudding up.

The first thing I would suggest is to access the reservoir and pour out the fluid that is present. It's easy because of the flexible connection between it and the master cylinder. Take it loose and bend it upside down.

Now refill the reservoir and with gentle pumping strokes try bleeding the system through the rear caliper.  Be sure to read this post completely before starting the repair!

Continue doing this (pumping) until such time as you have regained the full pedal stroke (you can actually feel the fluid pumping through the complete pedal stroke) accompanied with a good solid fluid flow at the bleed valve on the rear caliper.

it may take a full can of new fluid to achieve a good result. Bleeding and refilling the reservoir many times. What you are trying to achieve is to get all the crud out of the master cylinder and thru the piping into the caliper and out the bleed valve.

At first it may seem like you're getting no results but don't despair yet.  Don't use full strokes but rather short gentle strokes trying to get the cups inside the master cylinder to start sealing and pushing brake fluid. You will be able to feel this effect starting to happen.

Remember that with every push of the pedal there needs to be a release of the bleed valve on the caliper. Failure to do this simple little step will result in nothing but continuous failure.

A tip here is that after refilling the reservoir tap the hose connecting the two assemblies a few times to release any air bubbles that may have gotten stuck within the tube.  You want to insure you will not pump any air into the system. Air in the master cylinder can cause additional difficulty for this repair.

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[Tx Bohemian]

Thanks for the info fellas, valuable stuff.

I was able to secure a new complete cyl from a place in Pasadina with help from Wizard (Thanks!)

With the history of trouble I've had with this rear brake system (and the bike itself) I felt this is the best thing to do and I won't have to worry with this for a long time, if ever again.

Plus currently it has a braided line on it which doesn't fit properly and turned a nasty yellow color. I got an original hose/tube assy I bought soon after I got this bike ready to install.  This will be a good opportunity to put it on.

Again, thanks for the responses.