Topic: Cb550 caliper advice

[P.abrera]

Rehab'ing a mistreated cb550 front caliper. Needs a lotta love as you can see

[P.abrera]

Had a whoopsie with the bleeder, sheared off left half of itself stuck in there. Any suggestions on how to get it out?




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[P.abrera]

Will likely need a new piston too as this doesnt look like it'l clean up without some pitting.






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[calj737]

First off, you need to soak that whole caliper in rust penetrant. Then, you might be able to get the bleeder screw out with some needle nose, and lots of heat.

You'll likely have to resort to using a grease gun to pump grease into the caliper to remove the piston. Then, a new phenolic piston from Godferrey is highly recommended, with a new piston seal. Be 110% sure that the groove is perfectly clean! and shiny. Assemble using brake assembly lube.

Also, remove and lubricate the pivot bolt on the caliper mounting arm. On the caliper, there's a small hollow locating pin to hold the pad, replace or repair that as well. All the bodies of these parts are aluminum, so they'll clean up very nicely.

[Muckinfuss]

buy a replacement.  save the headaches.  If it was just one of those problems that you were fixing, that's one thing, but you're basically looking to re-manufacture a part with unknown results.  I've purchased just the 'working' part of the caliper for 70 bucks in nice shiny new condition.  Add a phenolic piston for 50 bucks with a new rubber and you're off an running.  You can also pay more for the whole assembly from David Silver.

[Tempast]

Sorry to derail, but aren't the 550 pistons stainless like the 750s?
What would be the purpose of using a phenolic piston? They're plastic and tend to seize and break on removal. I understand they can be significantly cheaper but the stainless ones should last almost forever if you don't leave the bike out and there's no water in the fluid.

[calj737]

Phenolic doesn't corrode, won't pit, weighs less, and are overall, a better material.

[DavePhipps]

550 pistons were not stainless. The are chromed steel and very prone to corrosion. Phenolic and stainless pistons are the way to go.

[Tempast]

Ah, that's what I was thinking of. My dad got a stainless one for his 750.

[Muckinfuss]

just to note: phenolic is used in most race applications, both cars and cycles.  Several US cars/trucks have them as OEM standard equipment for many years now.  It is superior to stainless....don't kid yourself, stainless will also rust if given the opportunity.