Topic: Need help with front brakes

[Cooper262]

I’ve got a 76 cb550 and i was working on the brakes today and bled the brakes and noticed on one side air kept coming out. after awhile of trying brake fluid stopped coming out but the reservoir was still full. And my brakes worked mostly fine before trying to bleed them. Im 90% sure i was bleeding them correct because i would open the bleed screw pull the lever back and close it again and then let go of the lever. So any help would be greatly appreciated!

Edit: I don’t think i made this too clear but it doesn’t seem to be pulling any break fluid from the MC but before i tried bleeding the brakes they worked fine for the most part just a bit spongy

[scunny]

Pump your brake lever slowly, while holding the lever in, open the bleed valve then tighten it. repeat till the brake works as it should.

[ekpent]

Yes do not open the bleed screw until you have gently pumped and pulled in the lever. Open when lever is pulled in and then close and release lever.

[BenelliSEI]

Honda recommends not pulling the lever right to the grip. Tape a piece of scrap wood about 3/8” thick to the grip to prevent too long a stroke and follow the directions above.

[scottly]

I’ve got a 76 cb550 and i was working on the brakes today and bled the brakes and noticed on one side air kept coming out. after awhile of trying brake fluid stopped coming out but the reservoir was still full.

I knew a guy that had the exact same symptoms once, and it turned out that he didn't know the master cylinder cap had a rubber cup/bladder/gasket thing that usually came out with the cap. His was stuck to the top of the MC reservoir, and since it was his first rodeo he filled the cup part with brake fluid, and then couldn't figure out why the MC wouldn't bleed, and the more he tried, the worse it got. Once he pulled the rubber part (and dumped out the brake fluid), filled the reservoir and bled the system, and reinstalled the rubber part over the fluid instead of under it, his problems were solved.

[Don R]

 ^ made me laugh!

[Stev-o]

^ made me laugh!

+1!  Now that is a rookie mistake!

[Bailgang]

^ made me laugh!

+1!  Now that is a rookie mistake!

Off topic but it reminds of the first time I bled the brakes on my 83 Goldwing. I bled the left front caliper and started bleeding the right front but nothing was happening when I'd crack the bleed screw open, not even the lever on the front MC was going down but I kept trying anyhow. I finally gave up figuring I must have a blocked brake line some where so I started tracing the right front caliper brake line only to find out it wasn't leading to the front MC at all. To put it simply I found out that 83 was the first year of GL's where the right front calipers were linked with the rear brake.

[Don R]

 The bookkeeper in our plumbing shop added ATF to his brake master cylinder. Realizing what he had done, he then took it to a dealership which promptly replaced everything brake related.   $$$ wow.
 
  Sorry for the hijack, let us know how it works out, I've had rusted closed bleeder screws too, they can be drilled open. I did buy the speed bleeders for my gl1000, the built-in check valve made it easier to bleed them. I forget the thread size, but they are available for cb's too.
 
   Another trick is pump up the brake then put a few rubber bands on the lever, thump the hoses slightly to release the surface tension on any air bubbles and leave it overnight, the air may float back up to the master cylinder and be released into the reservoir the next time you operate the lever. I saw a photo of Yoshimura doing that to a complete system on a bench. Good enough for them, good enough for me.
  There is also a tiny air return hole in the bottom of the m/c, it can become plugged and opened with a tiny wire.

[BenelliSEI]

Check th hole Don describes in his last sentence. Important.