Gap Too Tight After Replacing Disc Pads

[[email protected]]

I replaced my rear Hayes Hydraulic disc pads. Everything went fine,
exept afer I installed
my wheel back, it can hardly turn, because the gap between the new pads
seems to be too small.

I followed Hayes instruction by pushing pistons on both sides as far
back as I could with
a 10 mm ranch. But the gap is still too tight for the wheel to spin
freely. These pads are genuine Hayes parts that I puchased from Hayes
dealeres on the net.

I have also pumped the brake lever several times thinking that it may
self adjust the tighness.
But it did not help.

Did I not push the piston hard enough so that it did not reach the
bottom? I felt that I might break something if I had pushed any harder.


I'd appreciate any advice on how to fix this problem. Thanks in advance!

 

[Dre]

<[email protected]> wrote in message
news:[email protected]...
>I replaced my rear Hayes Hydraulic disc pads. Everything went fine,
> exept afer I installed
> my wheel back, it can hardly turn, because the gap between the new pads
> seems to be too small.
>
> I followed Hayes instruction by pushing pistons on both sides as far
> back as I could with
> a 10 mm ranch. But the gap is still too tight for the wheel to spin
> freely. These pads are genuine Hayes parts that I puchased from Hayes
> dealeres on the net.
>
> I have also pumped the brake lever several times thinking that it may
> self adjust the tighness.
> But it did not help.
>
> Did I not push the piston hard enough so that it did not reach the
> bottom? I felt that I might break something if I had pushed any harder.
>
>
> I'd appreciate any advice on how to fix this problem. Thanks in advance!
>
Yep, had the exact same problem when I changed my fronts just last week

What I did was push the pistons all the way back in so the top of the piston
is flush with the top of its bore.

Another way is to jam the plastic card you get with the brakes in between
the new pads, this also pushes the pistons back into their bores, but I find
the 10mm spanner trick easier, only problem is you generally need to remove
the caliper to do it.

If your not pushing on the pin that holds the pad in, you can push as hard
as you like, you wont break anything...

HTH

Cheers Dre

 

[Michael Dart]

[email protected] wrote:
> I replaced my rear Hayes Hydraulic disc pads. Everything went fine,
> exept afer I installed
> my wheel back, it can hardly turn, because the gap between the new
> pads seems to be too small.
>
> I followed Hayes instruction by pushing pistons on both sides as far
> back as I could with
> a 10 mm ranch. But the gap is still too tight for the wheel to spin
> freely. These pads are genuine Hayes parts that I puchased from Hayes
> dealeres on the net.
>
> I have also pumped the brake lever several times thinking that it may
> self adjust the tighness.
> But it did not help.
>
> Did I not push the piston hard enough so that it did not reach the
> bottom? I felt that I might break something if I had pushed any
> harder.
>
>
> I'd appreciate any advice on how to fix this problem. Thanks in
> advance!

Before I take my old pads out I stick a large flat bladed screwdriver in
between them and twist it to spread the calipers back out. Don't do this to
your new pads as it will break the material off the backing.

As mentioned the plastic shipping block that comes with some of Hayes brakes
is useful in spreading new pads apart. If you don't have one check your LBS
for a spare.

Mike

 

[[email protected]]

Thanks for the advice. I took out the pads and pushed the pistons
further more with another ranch as a leverage and this fixed the
problem. All you need is that additional paper thin clearance to let
the wheel spin freely.

Thanks again.


Dre wrote:

> Yep, had the exact same problem when I changed my fronts just last week
>
> What I did was push the pistons all the way back in so the top of the piston
> is flush with the top of its bore.
>
> Another way is to jam the plastic card you get with the brakes in between
> the new pads, this also pushes the pistons back into their bores, but I find
> the 10mm spanner trick easier, only problem is you generally need to remove
> the caliper to do it.
>
> If your not pushing on the pin that holds the pad in, you can push as hard
> as you like, you wont break anything...
>
> HTH
>
> Cheers Dre

 

[Roberto Baggio]

Take out your old pads.

Push the pistons back into the calipers with a box end wrench. Walk the
pistons slowly, alternating between each side, until they are fully pushed
into the caliper half.

Install new brake pads.

Put wheel back on bike.

Now, the trick. You will have a gap between the rotor and each pad. Put a
"spacer" (something like a business card) between the rotor and the pad
(each side). It may be tight, and a way to get the card well in there is to
rotate the wheel so the spacer is sucked in between the rotor and pad. With
the spacers in place, slow and firmly pump the brake lever about 20 times.
Because the spacers are in there, fluid will be forced back up into the
reservoir. Finally, remove the spacers and pump the brake lever a few
times.

One other thing that is quick and easy to do, and often helps with brake
performance. When the pad wears, the piston tends to rest farther and
farther out of the caliper half. This can allow it to accumulate crud on
it, and this crud will can cause a lot of stiction when new pads are
installed. During the new pad installation, with the old pads removed, push
easily on the brake lever so as to force the pistons out a bit. Be careful
not to force them out too far. With the pistons out a bit, you can use a
soft rag to clean the outside of the piston, and then apply a think layer of
brake fluid. This usually makes for a piston that moves in/out much
smoother.

<[email protected]> wrote in message
news:[email protected]...
>I replaced my rear Hayes Hydraulic disc pads. Everything went fine,
> exept afer I installed
> my wheel back, it can hardly turn, because the gap between the new pads
> seems to be too small.

 

[Dre]

<[email protected]> wrote in message
news:[email protected]...
> Thanks for the advice. I took out the pads and pushed the pistons
> further more with another ranch as a leverage and this fixed the
> problem. All you need is that additional paper thin clearance to let
> the wheel spin freely.
>
> Thanks again.
>
>
> Dre wrote:
>
>> Yep, had the exact same problem when I changed my fronts just last week
>>
>>
>> What I did was push the pistons all the way back in so the top of the
>> piston
>> is flush with the top of its bore.
>>
>> Another way is to jam the plastic card you get with the brakes in between
>> the new pads, this also pushes the pistons back into their bores, but I
>> find
>> the 10mm spanner trick easier, only problem is you generally need to
>> remove
>> the caliper to do it.
>>
>> If your not pushing on the pin that holds the pad in, you can push as
>> hard
>> as you like, you wont break anything...
>>
>> HTH
>>
>> Cheers Dre

Good work, the Hayes brakes are awesome (stopping power wise), but they can
be a bit finiky to setup. Once you have them nailed though they are bloody
great.

Cheers Dre