Page 1 of 1
What purpose do these serve ?
Posted: Thu Mar 06, 2025 3:21 pm
by Gregor
This solid cylindrical part that sits within the rear brake piston what’s it for ?
Never noticed it before, the front brake pistons don’t have them.
Re: What purpose do these serve ?
Posted: Thu Mar 06, 2025 3:57 pm
by mangocrazy
Does the centre section move outwards when the rear brake is pumped? I've seen similar on cars when there's either a handbrake piston, or on certain 'Superduplex' systems where there are two brake fluid circuits operating different (concentric) pistons in the same caliper.
Re: What purpose do these serve ?
Posted: Thu Mar 06, 2025 4:17 pm
by Gregor
mangocrazy wrote: Thu Mar 06, 2025 3:57 pm
Does the centre section move outwards when the rear brake is pumped? I've seen similar on cars when there's either a handbrake piston, or on certain 'Superduplex' systems where there are two brake fluid circuits operating different (concentric) pistons in the same caliper.
No, the centre part doesn’t move independently, this is off my yamaha xt660z.
Re: What purpose do these serve ?
Posted: Thu Mar 06, 2025 4:28 pm
by Skub
I always assumed they were to help slow transferring the heat from the pistons to the brake fluid.
Dunno if that's true or not,just makes sense to me.
Re: What purpose do these serve ?
Posted: Thu Mar 06, 2025 7:27 pm
by Rockburner
Skub wrote: Thu Mar 06, 2025 4:28 pm
I always assumed they were to help slow transferring the heat from the pistons to the brake fluid.
Dunno if that's true or not,just makes sense to me.
That would make sense.
I always thought they were just load spreaders.
Re: What purpose do these serve ?
Posted: Thu Mar 06, 2025 8:04 pm
by Le_Fromage_Grande
It's to keep the shit out of the hole
Re: What purpose do these serve ?
Posted: Thu Mar 06, 2025 8:14 pm
by Skub
Rockburner wrote: Thu Mar 06, 2025 7:27 pm
Skub wrote: Thu Mar 06, 2025 4:28 pm
I always assumed they were to help slow transferring the heat from the pistons to the brake fluid.
Dunno if that's true or not,just makes sense to me.
That would make sense.
I always thought they were just load spreaders.
Le_Fromage_Grande wrote: Thu Mar 06, 2025 8:04 pm
It's to keep the shit out of the hole
Could be all those things.
Re: What purpose do these serve ?
Posted: Thu Mar 06, 2025 8:31 pm
by David
Don't think it's a load spreader...Methinks the heat answer was more likely....reduced surface area = slower dissipation.
Re: What purpose do these serve ?
Posted: Fri Mar 07, 2025 9:53 am
by A_morti
What that lot said.
Also:
It's a Brembo caliper with aluminium pistons, I think? So maybe to prevent wear on the piston from the steel pad.
Reduce vibration/squeal.
Re: What purpose do these serve ?
Posted: Sat Mar 08, 2025 12:00 am
by ZRX61
They're isolators
Re: What purpose do these serve ?
Posted: Sun Mar 09, 2025 9:59 pm
by Ssray
Isolators, for heat and squeal