Topic: Finally . . . the seized brake piston is unstuck

[Stev-o]

Late Edit:  The back drum brake on the CB750 is working extremely well. Quick response and strong stopping power.  Very pleased! 

Even though the rear brake seems to be working well, I would disassemble and check/replace the rear shoes since the bike has been sitting for 9 years.  The brake lining has been known to come free of the metal shoe [most are just glued on]

On one of my project bikes, the shoes were a bit worse than expected!

[kyle750]

 I will need to remove the rear wheel hub when assembling the new DID rim, spokes, and tire.  I will be sure to inspect the rear drum brake shoes at that time.  Probably would be best to just go ahead and replace the shoes just to be safe. Living in Thailand I have seen really bizarre things happen to glue.  I wear fairly expensive running shoes that I buy ahead of time (hard to find large size shoes here in Thailand).  Shoes were never worn  and when I went to put them on the glue on the soles just disintegrated and they fell apart. Never seen anything like it.   

[PeWe]

My CB750 K2 with a new David Silver rotor described to be improved. New caliper and MC work fine in legal speeds. EBC FA12V orange pads.

Not much faster for an almost safe stop. Need to be alert and see problems in time, before they happen. Use gearbox too.

My K6 has same rotor but 2 of them, same  DSS MC. Stock calipers.
This stops good enough in higher speeds with DSS low priced pads.

I have read about guys here with good single front brake and stock rotor. Maybe different MC only or a caliper too.

https://good-bits.co.uk/product-category/braking/
I see now that they have a caliper bracket for K3-K6 fork lowers (marked 341 on inside) to use AP racing caliper.
Maybe they can do for earlier forks too.

[Don R]

 I've also seen the rear shoe de-laminate, I've had good luck with scuffing the rotor with scotchbrite gasket remover discs and sanding the glaze off of a stock set of brake pads. I do use my large shop vac with a hepa filter to collect the dust in case there is asbestos in them. 
 My best results came from two F1 calipers and two drilled rotors. I practiced stopping until I rippled the front tire.
 
 

[Deltarider]

I've also seen the rear shoe de-laminate, [... ]

Question is... were they OEM or aftermarket? I have heard of some aftermarket products de-laminating. Mine is still the original and does not de-laminate.

[bryanj]

Depends on storage and environment, in an atmosphere where you get the white corrosion on the alloy they will all delaminate

[kyle750]

It will be a while until I can get to the back wheel so inspecting the rear drum brake shoes is still a long way off. Brakes are so important IMO it is just not worth the risk using old brake shoes.  Right now they appear to be working OK but for safety and peace of mind it is better to replace.  I am going to order OEM Honda  rear brake shoes 06430-393-405  from the same seller in Japan  who I purchased the original Honda front fork rubber boot covers. Price on the brake shoes is $54 with free shipping from Japan.  First experience with this seller was Excellent +++ with excellent communication and super fast shipping. 

[Kelly E]

I've seen two sets of Honda rear brake shoes delaminate. It was on my 74' CB 550 K0 and the 70' CB 450 DOHC we did a couple of years ago.

[bryanj]

I have seen a lot as it tends to be damper and colder in UK!

[seanbarney41]

lots of damp and cold here in Michigan too, and never seen a Honda shoe delaminate out of dozens.  Have seen BMW pads weld themselves to the rotor...only way I could get the front wheel to roll was to remove the whole wheel which ripped the crumbled lining off the backing

[newday777]

I have seen a lot as it tends to be damper and colder in UK!

You probably haven't spent winter's in New Hampshire then. Lots of deep cold and damp here.
In the past 3 years I've had 2 sets that were full delam from lots of moisture, probably left outside and water collected in the hub, rusted spokes and rusted brake contact area. I had to whale on a sledge to get the axle out on one trying to salvage the hub, but decided to scrap it because of the rust pitting. I've also had 3 sets of brake shoes that were partially delam, lots of white powder residue on the shoes from moisture. So yes it does happen, probably the glue let go from improper storage in high moisture induced areas of poor storage of the wheel, maybe immersed in water at times.

[BenelliSEI]

My cb750K1 has excellent brakes. A few years ago, the rear got a bit “grabby”. When I pulled it apart one of the material strips had completely come away from the backing plate. Installed a pair of new ones from Honda. Should be good for another +50 years?