Topic: '75 CB550K1: The Driveway Shop

[ThelassianLupus]

Thought I'd share what I did today and start a thread for the ongoing maintenance of my CB550.
I'm not an experienced mechanic, but I was very eager to start learning when I got this bike. I bought it from a friend two years ago after taking a rider course and I've been riding and working on it ever since.

[ThelassianLupus]

One job I did last summer was a rebuild of the brake caliper. I think I did it poorly because the front wheel wouldn't turn freely and squeaked loudly at low speeds. So last week I decided to remedy that problem, while inspecting things I found that the brake hoses were cracked and needed to go.

[ThelassianLupus]

I took apart the master cylinder and caliper. All the rusty parts got an evaporust bath and cleanup while I waited for the new brake lines. Unfortunately this bike has a lot of rust I even found some on the tank and it looks to be under the paint in one spot. Underneath all the grease, grime, and rust I know there's a beautiful bike here!

[denward17]

Looks to have good bones, following on progress.

What's your plan for the bike?

I think I would address that tank so it won't rust any further and start leaking.

[HondaMan]

Removable rust, otherwise looks like a good starting point from here?
When you go to reassemble that brake caliper, install new rubber seal(s) on the piston in that caliper. They may be damaged from crud and are surely hard from age. The way the caliper retracts the puck is: when the brake is applied the puck slightly edges outward to make disc contact, and when released the rubber seals around that piston will pull the piston back when you release the brake lever. This is about 0.002" travel, typically: when the rubber is real old it no longer grips onto the puck so it slips out, and then it won't retract it, either. Then the pad drags, and squeaks.

And then, new rubber seals make it retract better again. It ain't much movement, but it's important!

[MauiK3]

Also check that all the moving parts on the support arm move freely. Fresh grease on the pin helps.

[ThelassianLupus]

Removable rust, otherwise looks like a good starting point from here?
When you go to reassemble that brake caliper, install new rubber seal(s) on the piston in that caliper. They may be damaged from crud and are surely hard from age. The way the caliper retracts the puck is: when the brake is applied the puck slightly edges outward to make disc contact, and when released the rubber seals around that piston will pull the piston back when you release the brake lever. This is about 0.002" travel, typically: when the rubber is real old it no longer grips onto the puck so it slips out, and then it won't retract it, either. Then the pad drags, and squeaks.

And then, new rubber seals make it retract better again. It ain't much movement, but it's important!

I appreciate this advice, but I regret to say I already reassembled the caliper. I imagine a fresh seal would have made it easier to seat the piston back in the caliper housing as well. The fit was really tight.

I'm noticing a slight slant on the surface of this brake pad and some gouge marks. Does this warrant replacing? If so I'll grab a new ring seal while I'm buying pads

[ThelassianLupus]

Looks to have good bones, following on progress.

What's your plan for the bike?

I think I would address that tank so it won't rust any further and start leaking.

Definitely looking to fix the tank soon. Any methods you'd recommend? I was thinking angle grinder with a wire wheel, though that approach may lack refinement.

I plan to use my available means to the best of my ability to keep this bike in great working condition. I don't want to sell it, or even really restore it to be "like new". I like it as an ongoing passion project and it's been a really great opportunity to learn and rely on this machine.

 I daydream sometimes about customizing it for use on some of the rougher roads in northern Maine so I can go on some more rugged adventures. But so far the most "custom" work I've done is the ammo can panniers. They have working turn signals though!

[HondaMan]

Those are some cool saddlebags!

[denward17]

Looks to have good bones, following on progress.

What's your plan for the bike?

I think I would address that tank so it won't rust any further and start leaking.

Definitely looking to fix the tank soon. Any methods you'd recommend? I was thinking angle grinder with a wire wheel, though that approach may lack refinement.

I plan to use my available means to the best of my ability to keep this bike in great working condition. I don't want to sell it, or even really restore it to be "like new". I like it as an ongoing passion project and it's been a really great opportunity to learn and rely on this machine.

 I daydream sometimes about customizing it for use on some of the rougher roads in northern Maine so I can go on some more rugged adventures. But so far the most "custom" work I've done is the ammo can panniers. They have working turn signals though!

Just normal, sanding down/priming/painting, assuming no pin holes.

[HondaMan]

Looks to have good bones, following on progress.

What's your plan for the bike?

I think I would address that tank so it won't rust any further and start leaking.

Definitely looking to fix the tank soon. Any methods you'd recommend? I was thinking angle grinder with a wire wheel, though that approach may lack refinement.

I plan to use my available means to the best of my ability to keep this bike in great working condition. I don't want to sell it, or even really restore it to be "like new". I like it as an ongoing passion project and it's been a really great opportunity to learn and rely on this machine.

 I daydream sometimes about customizing it for use on some of the rougher roads in northern Maine so I can go on some more rugged adventures. But so far the most "custom" work I've done is the ammo can panniers. They have working turn signals though!

It looks like the tires on it are good for "dirt road encounters", as we used to call them. It's good to consider alternate tire patterns, away from high-speed hiway types, for those non-paved adventure rides. I might raise one point to consider when thinking of new tires: don't go larger than 110/90x18 rear in size, or maybe 120/80x18 for a little wider footprint, or else you'll discover the sidestand becomes too short! The 80-profile tire will help prevent that little bug from biting. The 80-profile tire today is closer to the old 3.75x18 rear tire it sported from Honda.

[Stev-o]

And then, new rubber seals make it retract better again. It ain't much movement, but it's important!

I'm noticing a slight slant on the surface of this brake pad and some gouge marks. Does this warrant replacing? If so I'll grab a new ring seal while I'm buying pads

If you still have the caliper off the bike, I would install new pads and a seal.  If no, ride on!