"Chris Bartram" <news@delete.me.piglet-net.net> wrote in message
news:kLtfe.27852$G8.25941@text.news.blueyonder.co. uk...
> Nathan Lucas wrote:
> > use copper grease where the pad touches the piston and caliper.
> >
> Yes, i knew it was intended for that.
>
> >
> > do not use copper grease on the pins that the caliper slides on. these
have
> > a ptfe insert in (or should have!) and do not need grease!
> >
> ......but I didn't know that. What you say is borne out by the Haynes
> manual (well, the Golf haynes manual- the Audi A3 one isn't out
> yet.....) as it doesn't mention greasing the guide pins at all.
> Presumably the thing to do is just clean them with brake cleaner spray,
> and leave alone otherwise.

i've just overhauled the calipers on my rocco. i only touched the sliders
as the rubbers on them were completely perished. basically, as long as they
slide ok, you don't need to touch them at all. the new rubbers i got came
with a special rubber friendly grease, but this was to aid installation
only. you put a bit on the outside of the rubber bush so you can slide it
in without damaging it. there's then a ptfe collar that goes inside this,
then the metal slider bar. i just gave this a polish with a bit of white
spirit and a rag and made sure it was completely dry before putting it back
in.

it is good practice to open the bleed nipple when you push the piston back.
some abs systems get upset if you don't, and there is a (small) risk of
inverting the seals in the master cylinder. i usually change the brake
fluid at the same time as the pads.

 

"Chris Bartram" <news@delete.me.piglet-net.net> wrote in message
news:kLtfe.27852$G8.25941@text.news.blueyonder.co. uk...
> Nathan Lucas wrote:
> > use copper grease where the pad touches the piston and caliper.
> >
> Yes, i knew it was intended for that.
>
> >
> > do not use copper grease on the pins that the caliper slides on. these
have
> > a ptfe insert in (or should have!) and do not need grease!
> >
> ......but I didn't know that. What you say is borne out by the Haynes
> manual (well, the Golf haynes manual- the Audi A3 one isn't out
> yet.....) as it doesn't mention greasing the guide pins at all.
> Presumably the thing to do is just clean them with brake cleaner spray,
> and leave alone otherwise.

i've just overhauled the calipers on my rocco. i only touched the sliders
as the rubbers on them were completely perished. basically, as long as they
slide ok, you don't need to touch them at all. the new rubbers i got came
with a special rubber friendly grease, but this was to aid installation
only. you put a bit on the outside of the rubber bush so you can slide it
in without damaging it. there's then a ptfe collar that goes inside this,
then the metal slider bar. i just gave this a polish with a bit of white
spirit and a rag and made sure it was completely dry before putting it back
in.

it is good practice to open the bleed nipple when you push the piston back.
some abs systems get upset if you don't, and there is a (small) risk of
inverting the seals in the master cylinder. i usually change the brake
fluid at the same time as the pads.

 

"Chris Bartram" <news@delete.me.piglet-net.net> wrote in message
news:kLtfe.27852$G8.25941@text.news.blueyonder.co. uk...
> Nathan Lucas wrote:
> > use copper grease where the pad touches the piston and caliper.
> >
> Yes, i knew it was intended for that.
>
> >
> > do not use copper grease on the pins that the caliper slides on. these
have
> > a ptfe insert in (or should have!) and do not need grease!
> >
> ......but I didn't know that. What you say is borne out by the Haynes
> manual (well, the Golf haynes manual- the Audi A3 one isn't out
> yet.....) as it doesn't mention greasing the guide pins at all.
> Presumably the thing to do is just clean them with brake cleaner spray,
> and leave alone otherwise.

i've just overhauled the calipers on my rocco. i only touched the sliders
as the rubbers on them were completely perished. basically, as long as they
slide ok, you don't need to touch them at all. the new rubbers i got came
with a special rubber friendly grease, but this was to aid installation
only. you put a bit on the outside of the rubber bush so you can slide it
in without damaging it. there's then a ptfe collar that goes inside this,
then the metal slider bar. i just gave this a polish with a bit of white
spirit and a rag and made sure it was completely dry before putting it back
in.

it is good practice to open the bleed nipple when you push the piston back.
some abs systems get upset if you don't, and there is a (small) risk of
inverting the seals in the master cylinder. i usually change the brake
fluid at the same time as the pads.

 

> it is good practice to open the bleed nipple when you push the piston back.
> some abs systems get upset if you don't, and there is a (small) risk of
> inverting the seals in the master cylinder.

I'd read that. I've never done it in the past on my old
scirocco/golf/Ibiza etc, but the A3 I have now has ABS so it seems
sensible. Apparently the MkIII Vauxhall Astra is particularly prone to
the master seals inverting if you don't use that method.

 

> it is good practice to open the bleed nipple when you push the piston back.
> some abs systems get upset if you don't, and there is a (small) risk of
> inverting the seals in the master cylinder.

I'd read that. I've never done it in the past on my old
scirocco/golf/Ibiza etc, but the A3 I have now has ABS so it seems
sensible. Apparently the MkIII Vauxhall Astra is particularly prone to
the master seals inverting if you don't use that method.

 

> it is good practice to open the bleed nipple when you push the piston back.
> some abs systems get upset if you don't, and there is a (small) risk of
> inverting the seals in the master cylinder.

I'd read that. I've never done it in the past on my old
scirocco/golf/Ibiza etc, but the A3 I have now has ABS so it seems
sensible. Apparently the MkIII Vauxhall Astra is particularly prone to
the master seals inverting if you don't use that method.

 

"Chris Bartram" <news@delete.me.piglet-net.net> wrote in message
news:Ifwfe.28017$G8.26303@text.news.blueyonder.co. uk...
>
> > it is good practice to open the bleed nipple when you push the piston
back.
> > some abs systems get upset if you don't, and there is a (small) risk of
> > inverting the seals in the master cylinder.
>
> I'd read that. I've never done it in the past on my old
> scirocco/golf/Ibiza etc, but the A3 I have now has ABS so it seems
> sensible. Apparently the MkIII Vauxhall Astra is particularly prone to
> the master seals inverting if you don't use that method.

my last car was a J reg mk3 astra. i only read that you should undo the
nipples a few months ago, so it's something that i've never done until now.
that said, now i know the potential problems you can cause i always do.

 

"Chris Bartram" <news@delete.me.piglet-net.net> wrote in message
news:Ifwfe.28017$G8.26303@text.news.blueyonder.co. uk...
>
> > it is good practice to open the bleed nipple when you push the piston
back.
> > some abs systems get upset if you don't, and there is a (small) risk of
> > inverting the seals in the master cylinder.
>
> I'd read that. I've never done it in the past on my old
> scirocco/golf/Ibiza etc, but the A3 I have now has ABS so it seems
> sensible. Apparently the MkIII Vauxhall Astra is particularly prone to
> the master seals inverting if you don't use that method.

my last car was a J reg mk3 astra. i only read that you should undo the
nipples a few months ago, so it's something that i've never done until now.
that said, now i know the potential problems you can cause i always do.

 

"Chris Bartram" <news@delete.me.piglet-net.net> wrote in message
news:Ifwfe.28017$G8.26303@text.news.blueyonder.co. uk...
>
> > it is good practice to open the bleed nipple when you push the piston
back.
> > some abs systems get upset if you don't, and there is a (small) risk of
> > inverting the seals in the master cylinder.
>
> I'd read that. I've never done it in the past on my old
> scirocco/golf/Ibiza etc, but the A3 I have now has ABS so it seems
> sensible. Apparently the MkIII Vauxhall Astra is particularly prone to
> the master seals inverting if you don't use that method.

my last car was a J reg mk3 astra. i only read that you should undo the
nipples a few months ago, so it's something that i've never done until now.
that said, now i know the potential problems you can cause i always do.

 

"Nathan Lucas" <lucas.autotrash@tesco.net> wrote in message
news:jpwfe.4288$6W2.1110@newsfe2-gui.ntli.net...
>
> "Chris Bartram" <news@delete.me.piglet-net.net> wrote in message
> news:Ifwfe.28017$G8.26303@text.news.blueyonder.co. uk...
>>
>> > it is good practice to open the bleed nipple when you push the piston
> back.
>> > some abs systems get upset if you don't, and there is a (small) risk of
>> > inverting the seals in the master cylinder.
>>
>> I'd read that. I've never done it in the past on my old
>> scirocco/golf/Ibiza etc, but the A3 I have now has ABS so it seems
>> sensible. Apparently the MkIII Vauxhall Astra is particularly prone to
>> the master seals inverting if you don't use that method.
>
> my last car was a J reg mk3 astra. i only read that you should undo the
> nipples a few months ago, so it's something that i've never done until
> now.
> that said, now i know the potential problems you can cause i always do.
>
>
When I worked in the power industry we used silicone grease on "O" rings
which had to withstand 1500 lb/in sq and 150 deg C, as recommended by the
manufacturers. I have used Copaslip on brake calipers on many occasions
without problems, the trick being to apply a smear sparingly and not lather
it on too heavily.

Pilgarlick