Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: florence on April 09, 2021, 02:31:37 PM

Title: Brake caliper piston
Post by: florence on April 09, 2021, 02:31:37 PM
I'm just about to replace the piston on my fron brake and notice there are Honda ones and pattern ones.  Does anyone know if there is any difference?

Thanks
Title: Re: Brake caliper piston
Post by: Bryanj on April 09, 2021, 02:44:02 PM
The stainless ones will last a lot longer and are actualy cheaper. Ebay item 262018047322 is a piston and seal kit listed as 400 but they are the same. I have fitted quite a few of these with no problems at all
Title: Re: Brake caliper piston
Post by: florence on April 09, 2021, 02:46:56 PM
Thanks Bryan, that is good info because I seem to be always changing these every couple of years.  They get rust spots and obviously that won't be the case with stainless.  Very grateful to you sir.
Just ordered it, simple as that.
Thanks again
Title: Re: Brake caliper piston
Post by: florence on April 09, 2021, 05:07:20 PM
yes, you are right, especially with my bike which gets used all year round and lives outside.  I can coat most of the bike in oil and grease but the brake is one part which gets exposed to the elements.
 
Title: Re: Brake caliper piston
Post by: Bryanj on April 09, 2021, 05:20:55 PM
I have been using stainless since they first came out and that seller does quite a bit of good stuff along with special tools
Title: Re: Brake caliper piston
Post by: deltarider on April 09, 2021, 06:30:54 PM
What's with phenolic? I don't even know what it is. :-[
Title: Re: Brake caliper piston
Post by: K2-K6 on April 09, 2021, 07:05:48 PM
What's with phenolic? I don't even know what it is. :-[

High heat range resin construction. Effective, lightweight and has been used in some car production applications for years. Also good insulator so doesn't pass heat into fluid easily.
Downside, can be subject to chipping if someone trying to lever a piston back in to caliper is careless (happens a lot on mtb brake calipers with the owner butchering them  ::) )

Stainless,  you still have to protect with grease, else it'll cause the piston to "eat" the caliper aluminium from galvanic corrosion when subjected to salty road wash. Honda specify silicone grease around seal and bore to prevent water ingress.

Phenolic doesn't cause corrosion as far as I'm aware.
Title: Re: Brake caliper piston
Post by: K2-K6 on April 09, 2021, 07:45:07 PM
Pity we can't get Nitrite coated titanium, that would be nice.

We use that on MTB downhill bikes in hope six pot calipers

[attachimg=1]

One piece milled billet construction too, and made in Lancashire.
Title: Re: Brake caliper piston
Post by: deltarider on April 10, 2021, 06:43:37 AM
Thanks, K2-K6.
Title: Re: Brake caliper piston
Post by: florence on April 10, 2021, 10:30:39 AM
Silicon grease, not heard of this, are they all the same or are some more suitable for brakes?
Title: Re: Brake caliper piston
Post by: K2-K6 on April 10, 2021, 10:55:16 AM
Silicon grease, not heard of this, are they all the same or are some more suitable for brakes?

Unless specifically identified on product,  they are all all the same. Obviously kept away from friction surfaces, but on these it's not a risk from piston seal area. It is recommended in the very first Honda 750 workshop service manual for the caliper.

I use plumbing supplies to buy a little pot that lasts for ages, good in electrical connections too as it's virtually impervious to water ingress. I routinely use it on cars, HT lead ends, any terminals on things like Land Rover looms that are out in wet environments.
Title: Re: Brake caliper piston
Post by: K2-K6 on April 10, 2021, 10:56:29 AM
This one I use
https://www.plasticdrainage.co.uk/silicone-grease-100gm-7987.html?pid=7849&gclid=EAIaIQobChMI1KOqwrTz7wIV0eJ3Ch1yOwmvEAQYBCABEgIeRfD_BwE#fo_c=1765&fo_k=1b4e399750ed82bad18a0b7d14eb2889&fo_s=gplauk
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