Front Brake Caliper 1977 CB550F

[LukeM]

The bleeder valve is very stuck on my son's CB550F, and I'm hunting down another front brake caliper for his bike.  On the off chance you might have one or know someone who's got one, I would welcome any information.  I've seen some on EBay, but you never know what kind of shape they're in. I also recommended to my son that he rebuild the caliper and the master cylinder since the system is apart anyhow.  It'll build character.

Feel free to message me here if you can help.  I thank you in advance.
Luke M

[vern401]

Have you tried soaking it in PB blaster?
if he is going to rebuild it anyway try this.
1. remove the caliper from the bike.
2. use the brake to push the piston out or carefuly use compressed air if the master cylendar does not work
3. spray the inside and outside with some penetrating oil like PB Blaster where the bleed valve is. let soak in repeat spray 1-2 times per day for about 3 days.
4. try turning it out. if it moves only a little soak some more inside and out. Turn out and in to work it out.
5. If no movement remove the seals. use brake cleaner to remove the oil and let dry.
6. Not realy best way but here it goes. use a propane torch to heat the bleeder only. try to keep the caliper cool. this expands the bleeder some. try turning again but is best to let it cool first. repeat 3&4

[LukeM]

We've been dousing the bleeder screw in some good penetrating oil, and it's really on there.  Even tried some light tapping with a small hammer to get the oil to work in better.  The 550 manual says to use a 10mm wrench to loosen it, and it's so rounded over an 8mm won't close down on what's left.  Seems the previous owner tried to loosen it with a wrench or vise grip.

Thanks for the suggestion, but I think it's a goner.  I saw one on EBay for about 30 US + shipping.  A rebuild kit and brake pads for the caliper and the master cylinder and his bike will be braking for a LONG time.

Luke M

[vern401]

Not a bad price for Ebay. if you know someone with an easy out and a drill bit for it you may be able to get it out that way if you want. Does the piston move in and out easily? If it does and it's not leaking the seals are probably still good. I took one that did not want to move back in and cleaned it out with Pine-Sol and a tooth brush. Now it is working just fine. It had a build up of old fluid in there that was stopping it from moving freely. This also worked with the master cylendar on the same bike. It had sat for years. If you do it right you realy dont need a bleeder to bleed the caliper but it takes longer to do it. For $30 I'd do just what your talking about doing. My 78 750F has a bad bleeder on the rear but the caliper works just fine so I am not going to mess with it until it needs it.
Enjoy the bike and ride safe.
Vern