'76 CB750 front brake issues

legitmw

Been Around the Block
I recently bought my bike and when I got it there was no brake fluid in the line. I just filled the master cylinder and bled all the air out of the line so now the line and cylinder are filled with new fluid, but when I pull the handle the brake doesn't apply the brake. Not really sure what I should do next.
 
Get a manual?

Maybe you didn't bleed it right? After you were done did you have functioning brakes that then didn't work the next day? Or did you just bleed and bleed and never get good brakes?
Do you see fluid leaking out?
Sure the piston is moving in the caliper?
Might want to think about investing in a master and caliper rebuild kit.
Do yourself a favor and only buy them from Honda. They have them. The K&l or other aftermarket kits are junk and not worth the few dollar savings. Might want to think about new pads(don't care if they have meat on them) and some SS lines to give everything an overhaul
 
I'm pretty sure I bled it right. I had the nipple valve open and filled the master cylinder, when I pulled the brake handle, fluid would shoot out the nipple. When I had all the air out of the line I closed the nipple and topped off the master cylinder. My brake never functioned. No fluid is leaking out. I don't think the piston is moving. Before I did anything, when I pulled the brake lever it would come all the way to the handle with no resistance. Now it feels normal where I can only pull it in partially and it has resistance, the brake just does not move.
 
That will be my last resort. The bike was sitting for a while so it could just be stuck. I'll see how far I can take it apart and see what everything looks like
 
You need a special snap ring plier to rebuild the master.
I have done it without that tool, but much easier with it.
 
You may have air trapped in the lines still if you haven't properly bled the system.
With a length of hose going from the nipple to a bottle with an inch of brake fluid in the bottom and the nipple closed pump and hold the brake lever, open the nipple, fluid will flow out, tighten nipple, pump and hold lever again, open the nipple, fluid will flow out. Keep doing this until no more air bubbles come out in the fluid from the nipple
Youtube will show you how
 
keep bleeding. it can take up to 10 minutes of continous bleeding. pump, open valve, close valve, release pump. pump, open valve, close valve, release pump.. you get the idea. If fluid drops @ master resevoir, its going somewhere. If you have no leaks, the piston inside the caliper has to move.

take the caliper of the bike and bleed it till you pump the piston out. replace the o-ring and give the piston and housing a LIGHT AND DELICATE rub with a brillo-pad. apply brake grease and new o-ring. should be ok.

if you can not build up pressure, your master is shot. replace it with OEM kit, or find a replacement (OEM or nonOEM does not matter) on ebay
 
Finally got it fixed! Well not fixed yet but I got the piston out of the caliper. It was so rusted in place. I filled a grease gun with brake fluid and screwed it where the brake line would go (thank God it fit perfectly) and started pumping away, and the piston popped right out. A little rusty though!

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Piston is shot and you should replace it.
SS ones are available as are phenolic. Check out sohc4.net
 
Yea it has a lot of pitting. I looked there, but didn't find any place to buy new ones. I can't find any pistons online that are for my bike. Most are for 80's CB's.
 
Member of that board makes them so I know they are there.
If not many online aftermarket options, Honda might even have them.
 
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