Retracting brake pistons



D

Duncan

Guest
Hi,
I have a set of Hayes Nines. I've just worn my way through a set of pads
and discs[1] and replaced and installed a new set.
I can get the pistons to retract enough to fit the new discs and pads but
not enough for them to spin freely.
It's my understanding that when the lever is open the fluid is able to flow
back into the reservoir. I've tried wedging a screwdriver[2] between the
pads to hold them apart and left them overnight but when I remove it there
is always a bit of spring back to their original position.
Are there any tricks to getting them to retract further? It would make
sense to me to open the bleed valve briefly while they're held apart but I'm
not so sure so thought I'd ask for other options.

Cheers,
Duncan.

[1] Not very impressed to only get 3000 km out of the pads and discs. The
discs may have lasted a while longer but they had hit their service limit.
[2] A degreased and quite wide screwdriver so as not to damage the pads.
 
"Duncan" <[email protected]> wrote in message
news:[email protected]...
> Hi,
> I have a set of Hayes Nines. I've just worn my way through a set of pads
> and discs[1] and replaced and installed a new set.
> I can get the pistons to retract enough to fit the new discs and pads but
> not enough for them to spin freely.
> It's my understanding that when the lever is open the fluid is able to
> flow
> back into the reservoir. I've tried wedging a screwdriver[2] between the
> pads to hold them apart and left them overnight but when I remove it there
> is always a bit of spring back to their original position.
> Are there any tricks to getting them to retract further? It would make
> sense to me to open the bleed valve briefly while they're held apart but
> I'm
> not so sure so thought I'd ask for other options.
>
> Cheers,
> Duncan.
>




Remove the pads and lever / push on the piston with a 10mm box wrench.

http://www.hayesdiscbrake.com/pdf/General-45-14575BEnglishWeb.pdf

--
DTW .../\.../\.../\...

I've spent most of my money on mountain biking and windsurfing.
The rest, I've just wasted.
 
"D T W .../\..." <[email protected]> wrote in message
news:YsaAe.5198$rx4.513@trndny05...
> "Duncan" <[email protected]> wrote in message
> news:[email protected]...
> > Hi,
> > I have a set of Hayes Nines. I've just worn my way through a set of

pads
> > and discs[1] and replaced and installed a new set.
> > I can get the pistons to retract enough to fit the new discs and pads

but
> > not enough for them to spin freely.
> > It's my understanding that when the lever is open the fluid is able to
> > flow
> > back into the reservoir. I've tried wedging a screwdriver[2] between

the
> > pads to hold them apart and left them overnight but when I remove it

there
> > is always a bit of spring back to their original position.
> > Are there any tricks to getting them to retract further? It would make
> > sense to me to open the bleed valve briefly while they're held apart but
> > I'm
> > not so sure so thought I'd ask for other options.
> >
> > Cheers,
> > Duncan.
> >

>
>
>
> Remove the pads and lever / push on the piston with a 10mm box wrench.
>
> http://www.hayesdiscbrake.com/pdf/General-45-14575BEnglishWeb.pdf


Thank you. It seems the trick was the walking them in side to side. All my
efforts were a little lop sided while the pad was still in and they weren't
going as far as they could.
 
"Duncan" <[email protected]> wrote in message
news:[email protected]...
> "D T W .../\..." <[email protected]> wrote in message
> news:YsaAe.5198$rx4.513@trndny05...
>> "Duncan" <[email protected]> wrote in message
>> news:[email protected]...
>> > Hi,
>> > I have a set of Hayes Nines. I've just worn my way through a set of

> pads
>> > and discs[1] and replaced and installed a new set.
>> > I can get the pistons to retract enough to fit the new discs and pads

> but
>> > not enough for them to spin freely.
>> > It's my understanding that when the lever is open the fluid is able to
>> > flow
>> > back into the reservoir. I've tried wedging a screwdriver[2] between

> the
>> > pads to hold them apart and left them overnight but when I remove it

> there
>> > is always a bit of spring back to their original position.
>> > Are there any tricks to getting them to retract further? It would make
>> > sense to me to open the bleed valve briefly while they're held apart
>> > but
>> > I'm
>> > not so sure so thought I'd ask for other options.
>> >
>> > Cheers,
>> > Duncan.
>> >

>>
>>
>>
>> Remove the pads and lever / push on the piston with a 10mm box wrench.
>>
>> http://www.hayesdiscbrake.com/pdf/General-45-14575BEnglishWeb.pdf

>
> Thank you. It seems the trick was the walking them in side to side. All
> my
> efforts were a little lop sided while the pad was still in and they
> weren't
> going as far as they could.
>



Yes, It's easy after you've struggled for a while. Here's another good
info site from Slack.

http://www.pbase.com/slack/hayes_brakes

--
DTW .../\.../\.../\...

I've spent most of my money on mountain biking and windsurfing.
The rest, I've just wasted.