The International CBX Owners Association

I am bleeding the front brakes on my 80 but no matter what I do the right caliper continues to pump a very fine mist of air when I squeeze the brake lever. I have tried Teflon tape around the bleed screw to no avail. The brake lever does firm up and I can squeeze it to about an inch from the bar but it is not as firm as my 79. Also when I take it for a ride and do some hard braking the temperature of the right disc (85 degrees) is far lower than the left (135 degrees). This seems to suggest I still have air in the right caliper but I can't seem to get it out or know where air might be entering the system. I fitted new piston seals and tightened up the brake lines as hard as I dare. Any suggestions?
Thanks
Ross

Ross:

Seems like some air is still trapped - maybe in the splitter. I only use a Mity-Vac so what I suggest might not be applicable. I've described this before, but anyway, I remove the calipers and splitter intact, remove the right headlight bolt and fish the upper line and all out in front of the bike in a horizontal-as-I-can-get position. I prop everything up on saw horses and blocks. Then I can rotate the calipers and splitter as the Mity-Vac sucks fluid out of each caliper. You'd be amazed at how much air comes out as you rotate and wiggle the calipers and splitter. I then pump the pistons out farther than necessary, then push them back by hand just enough to fit over the discs, then reinstall the whole system. Takes about 10 or 15 minutes and you're done. You do need to thread tape and possibly grease the bleeder threads so you don't suck air.

Dave

My advice is to let gravity do its thing,try using two small bottles for clear plastic tubing from bleeders down to bottles on the floor,I put two small clean small coke bottles in a box behind front wheel,fluid will flow add fluid at master cylinder it will take a while ,tap all joints ,calipers with a soft mallet to jar air bubbles,pump up get a little pressure ,open up bleeders let it flow somemore and you'll soon have a decent brake ,not rock hard like current sportbikes thou!

I am with Dave, here. Applying suction to the bleed screws is the way to go. I installed steel braided brake lines on my Pro-link and had the front bled in 10 minutes by applying vacuum to the bleeders.

+2 agreeing with Dave. But, if you don't have a vacumm bleeding system, tie the brake lever about half way back to the grip. A zip tie, piece of electrical tape, anything will do. What this does is expose the return port in the master cylinder. Now you can take your time and let gravity do it's deed. A gentle bump on the lines or splitter, a little "tickle" of the lever, will release a bunch of little bubbles from return port. Turn the bars a bit left or right to get the bubbles headed up hill. Be careful not to slop any of the fresh DOT "X" fluid where you don't want it.

Bleed at the top banjo too Ross, although it sounds like the trouble is at the caliper. Where is this fine mist ejecting? Possible your bleed screw isn't sealing? Definitely wrap those with Teflon tape.

I might offer this for those who are needing to bleed the 'old fashioned way'; i.e., pump the lever and open/close the bleeder. Be certain that, as you slowly squeeze the lever, you close the bleeder BEFORE you reach the end of travel. That assures no air gets back into the caliper. Might seem to take a little longer; but, you only do it once this way. Just holding the lever at full travel while closing the bleeder doesn't prevent air from getting back into the caliper.

Thanks for all the tips. Lever is now as firm as I have ever had it so once it warms up down here I'll take it for a spin and see how it does.

I have one remaining issue and that's that the Shim Pad on the right caliper is very worn and when I pull the lever the caliper makes a slight clanking noise. If I take out the Shim Pad there is no noise. Is there a simple fix for this or do I need a new Shim? If so where can I find one as I have looked on many sites and the Honda 45116-371-006 SHIM B, PAD seems to be obsolete.
Thanks
Ross

Ross:

I have lots of those shims - right or left? The only other thing I've run into with brake bleeding is a partially plugged line or splitter. I always spray brake cleaner, followed by compressed air, through each line when I rebuild brakes, whether the lines are new or used. I've found lots of crud in both new and used lines.

Dave

Dave
It's the right one and I have to admit I did not think of blowing compressed air down the lines. They are 3 year old braided lines covered in shrink wrap black tube to look like the OEM lines. If I have issues tomorrow I'll blow the lines but right now I'm confident the brakes will be good.......famous last words!
Ross

Beautiful bike Ross!

Dave

Holy $hit Ross, the bike looks UNBELIEVABLE!

Better than showroom, Ross. Great work!

Took the 80 out yesterday and the front brake was terrific. Also the temperature readings on both discs were within 10 degrees of each other after some braking so it seems the problem is fixed.
Thanks for the comments on the bike. It was all done with help from many of you on this forum and at particularly tricky times with phones calls to Dave who was patient enough to walk me through different options to get the bike looking good and running well.
Ross

ajs350 wrote:...It was all done with help from many of you on this forum and at particularly tricky times with phones calls to Dave who was patient enough to walk me through different options to get the bike looking good and running well.
Ross

He did the same for me. Dave kicks ass.

Great job Ross, looks perfect.