[yardc28]

The brakes on my '03 Shadow ACE were a little sticky. Tried lubing up the pivot and any contact points which helped but didn't resolve the issue. I bought the bike used last year so I'm not sure what maintenance it's had on it. Clearly it had no maintenance on the MC.

The rebuild kit came today so I decided to give it a shot (I'm no mechanic but I can hold my own). Drained the fluid, which needed changing anyway, and tore apart the MC. Sure enough, the piston was grainy and the cups were worn down. I cleaned out the bore and installed the new piston with new cups, spring, washer, snap ring, and boot. I did not change the banjo bolt or its washers.

Got everything back together, topped off the fluid, and went to bleed it. I must have refilled the reservoir three times and never got any pressure in the brakes. I bled it a couple times out of the banjo. I'm noticing tiny bubbles coming out into the reservoir any time I pull the handle. I can only imagine there is a leak in there somewhere. My current thoughts:

The banjo washers: didn't replace, torqued the thing to hell to recrush them but maybe that's not good enough?

The cups: service manual says do not let cups turn inside out when sliding back into bore. I noticed the cups were slightly larger than the bore. It took a good amount of playing around to get the piston in. I was unable to see if the cups were inside out.

Any other thoughts? I just ordered some new OEM washers; they should be here next week so I can try them out.

Cheers

 

[cmonSTART]

How are you bleeding the master cylinder exactly? They can sometimes be a pain to bleed!

I bench bleed mine. Put it in a vice, no banjo bolt. Work the handle and cover the banjo hole with my thumb, then release. Remove thumb, work handle. Replace thumb, release. Etc.. Once I feel things working I plug the banjo hole with an earplug so I can bolt it back on the bike, then bleed normally.

You're positive everything is in the right place? Cup isn't backwards?

Good luck!

 

[Eye_m_no_angel]

"The banjo washers: didn't replace, torqued the thing to hell to recrush them but maybe that's not good enough?"

It's a good practice to replace them. (Don't over-torque stuff. It can cause cracks and failures in a part.)

C'monStart gives good advice on bench bleeding to get the air out of the MC. Just a small bubble trapped in there can cause all sorts of issues and push up tiny bubbles into the reservoir for days.

Sticking can also be a sign of the quad type seal on the caliper piston failing, or some other issue with the caliper.

Your tiny bubbles mean that there's air in the system somewhere, and it can get in anywhere. Start at the top, with your banjo washers, and work your way down. If you didn't hack at the lines any, then the next logical place to look is your bleed screws on the caliper. They can get worn out and leak air.

Work from the MC back to the wheel caliper, and work way more carefully then you thought you were before.

 

[yardc28]

Cheers guys. I hadn't heard of bench bleeding till I got the thing back together and started searching for people with similar issues. I will definitely do that next time.

To bleed the MC I just cracked the seal a bit and followed the same procedure as if I were bleeding from the caliper. Man did that make a mess, so I know the MC is good. I even took it off and covered the output with my finger to make sure there was pressure building.

Good call on the bleed screw, too. I'm definitely going to tape the threads up with teflon tape next time. Guess those tips in the service manual are there for a reason!

Thanks for the tips...the washers are coming in via snail mail (forgot what its like shipping with Amazon Prime) so I'll update when I get them

 

[yahmyxs]

did the brake work some before you worked the master cyl over?

master cyl usually don't go bad. What does happen, when a bike sits for a while, even a few months, is that the brake cylinder seal in the caliper freezes up. If they go dry, or get hard from sitting, you need to take the cylinder out...
hard sometimes. so take the entire caliper over to the vice and clamp the caliper cylinder in the vice, try no to marr it up.
slowly apply pressure to the caliper body until the cyl turns a little, them turn it back and forth until it begins to free...
I have done this a few times with frozen calipers and it saves alot of money. The key here is steady strong pressure, and if it is so stuck that it won't turn, you would have had to replace the caliper anyway... this way you know for sure. remember they were built to take apart and rebuild. like I said, if the master cyl worked a little bit, its not the master cyl.

 

[Unkle Krusty]

Calipers and things.

Today I took apart three calipers and a master cylinder. The master cylinder at the rear was still pumping, so with the caliper off, I pumped out the piston.

The front master cylinder was stuck, contrary to another opinion. So I could not pump out the front calipers. Instead I used air pressure, and that popped both of them out. Meanwhile the MC is soaking in some liquid wrench. I will probably need a new snap ring remover for the small snap ring.

One of the calipers had a gooey water mix in it, along with the brake fluid.
Sometimes they take forever to bleed. I have found that the proper grease ( green stuff ) for the caliper seal works better than other stuff. The piston should push in fairly easily. If it gets stuck, it is hitting the edge where the seal sits. Take it out and try again.

There are complete made in Taiwan master cylinders. Cost about $100-

Unkle Crusty*

 

[yardc28]

The brakes were working OK before I rebuilt the MC, aside from some stickiness - I would push it in and instead of being smooth it would kind of click. I found out this was due to the old piston wearing down: the thing was covered in tiny bits of metal. Fortunately it didn't look like it damaged the bore, though it is a possibility. The piston slides nice and smooth now, albeit with no pressure behind it.

From your suggestions I think I'll take the caliper off as well and make sure everything looks good there. I've even seen some people suggest hanging the caliper above the MC so that all the air travels up to the bleed valve.

Still waiting on those washers to come in; hopefully they'll be here for some weekend warrior work.

 

[Eye_m_no_angel]

I've even seen some people suggest hanging the caliper above the MC so that all the air travels up to the bleed valve.

I doubt you'll find a professional tech suggesting that. If you bleed the system properly you won't need to do that, and on most systems it wouldn't work anyway. There's too many places for an air bubble to get trapped, so it would have to be bled anyway.

 

[Williamdcollins]

Honda Shadow 2003 600 50000

Here is my two cents.

Bleeding can be a nightmare. The guys are so right. That said, I purchased a bleed kit from Harbor Freight that I use every year to pull from the bleed valve(ioosen) and at the same time keep adding fluid to the reservoir. In your case everything is empty to start so even harder. My brakes work fine but recently started to pulse a little but over winter will have my rotors resurfaced and rebuild my calipers. Can't remember the place to cut them but have it written down. I gave them my measurements so they could know if they could resurface it.

 

[yardc28]

Washers should be here today. I know that there needs to be one on either side of the bolt. I noticed that there is a ring around the old washers, I'm assuming this is the part that gets crushed. Is there an orientation that these need to be put on? I'm assuming the raised side would sit against the bolt. Or should the flat side be against the bolt?

Cheers

 

[Eye_m_no_angel]

If they're the kind with the rubber ring in the middle, it doesn't matter which way they face.

 

[yardc28]

We've got pressure! Turns out they weren't rings on the washer; they were actually created from getting torqued against a small flange on the bolt. I bet I put it on backwards last time and it allowed a small lead.

Either way, took the MC apart again, verified the piston and cups looked good, bench bled it, put her back on with the new washers, aaaand nothing. I must have bled it for about 15 minutes with hardly anything coming out before I decided to try a reverse bleed.

The reverse bleed worked like a charm. It must have gotten all those hard to reach bubbles out because I couldn't believe how much air was coming out of the reservoir. It still took a while but the second I felt a little pressure on the handle, man was I happy. At this point I bled it normally, each time getting a little more pressure.

Thanks for all the tips guys, unfortunately we're in the middle of a Nor'Easter right now so I can't take it for a test spin.