Audi 80 rear brake caliper (UK)
 

About to fit some new rear brake pads to an Audi 80 (1993). Can't find a
manual for this car but doing a quick web search I see that you can't
simply push the piston back into its bore as that will damage the
automatic handbrake mechanism, but instead you need a special tool that
winds the piston back in. Does anyone know if Halfords or similar sell
such a tool to do the job or am I looking at Audi main dealer prices?
Cheers.

Re: Audi 80 rear brake caliper (UK)
 

Mark wrote:

> About to fit some new rear brake pads to an Audi 80 (1993). Can't find a
> manual for this car but doing a quick web search I see that you can't
> simply push the piston back into its bore as that will damage the
> automatic handbrake mechanism, but instead you need a special tool that
> winds the piston back in. Does anyone know if Halfords or similar sell
> such a tool to do the job or am I looking at Audi main dealer prices?
> Cheers.
>

Halfords or most larger motor factors including Partco can supply the
tool, also from Machine Mart and other mail order suppliers.

Before trying to fit new pads make sure the handbrake cable is slackened
off.

Re: Audi 80 rear brake caliper (UK)
 

"awm" <thevillage@nohere.com> wrote in message
news:bms5it$320$2@sparta.btinternet.com...
> Halfords or most larger motor factors including Partco can supply the
> tool, also from Machine Mart and other mail order suppliers.
>
> Before trying to fit new pads make sure the handbrake cable is
slackened
> off.
Thanks for the quick reply, I will have a look tomorrow.
So far I've just removed the caliper section from it's carrier. Both the
bottom sliding pins on both calipers were really rusted and pitted, so I
suspect the piston will also be in a bad way. I was thinking of rotating
the piston in and pumping it back out a few times to losen it up before
reasembing.

Re: Audi 80 rear brake caliper (UK)
 

"Mark" <keep_it@thegroup.com> wrote in message
news:bms6gn$pjuh3$1@ID-123703.news.uni-berlin.de...
> "awm" <thevillage@nohere.com> wrote in message
> news:bms5it$320$2@sparta.btinternet.com...
> > Halfords or most larger motor factors including Partco can supply the
> > tool, also from Machine Mart and other mail order suppliers.
> >
> > Before trying to fit new pads make sure the handbrake cable is
> slackened
> > off.
> Thanks for the quick reply, I will have a look tomorrow.
> So far I've just removed the caliper section from it's carrier. Both the
> bottom sliding pins on both calipers were really rusted and pitted, so I
> suspect the piston will also be in a bad way. I was thinking of rotating
> the piston in and pumping it back out a few times to losen it up before
> reasembing.

If you think it's that bad, then you need to overhaul the caliper, which
means you'll probably need the special tool. The basic design of the rear
caliper is the same on all Audis of this vintage - the handbrake mechanism
means the pistons on the rear calipers have to be screwed in when you
retract the piston and screwed out when you dismantle the caliper. Some of
the mid-80s cars had a hexagon in the end of the piston and you used an
Allen key to twist the piston (be warned that the hexagon tended to rust
out, leaving you gripping the end of the piston with a self-grip wrench - be
very careful not to damage the piston if you have to do this). Some other
cars had pistons with a slot right across the piston and yet others have
just two slots on opposite sides on of the piston - the Sykes Pickavant tool
available from Halfords (£20) will cope with both of these last two types.

In any event you need a repair kit (main dealer stuff, but not expensive)
comprising the seal and dust boot for each side, since you'll need to take
the piston out to see if it's knackered. If it is, it will be obvious and
you'll need an exchange caliper - try German and Swedish or similar. If not,
just change the seal and boot and re-assemble.

The tool is well worth the money, BTW.

HTH

Jonathan

Re: Audi 80 rear brake caliper (UK)
 

"Jonathan Morton" <jonathan@removethisjonathanmorton.co.uk> wrote in
> The tool is well worth the money, BTW.

Thanks for the advice, I will get the tool tomorrow and have a closer
inspection. Will let you know how I get on.
Cheers.

Re: Audi 80 rear brake caliper (UK)
 

On Sat, 18 Oct 2003 21:06:08 +0100, Mark <keep_it@thegroup.com> wrote:

> "awm" <thevillage@nohere.com> wrote in message
> news:bms5it$320$2@sparta.btinternet.com...
>> Halfords or most larger motor factors including Partco can supply the
>> tool, also from Machine Mart and other mail order suppliers.
>>
>> Before trying to fit new pads make sure the handbrake cable is
> slackened
>> off.
> Thanks for the quick reply, I will have a look tomorrow.
> So far I've just removed the caliper section from it's carrier. Both the
> bottom sliding pins on both calipers were really rusted and pitted, so I
> suspect the piston will also be in a bad way. I was thinking of rotating
> the piston in and pumping it back out a few times to losen it up before
> reasembing.
>

If the piston moves back in with the tool then it's fine. New pin kits
aren't particularly expensive &they're easy to fit. If they rotate easily
you can screw the pistons back in with a bodged tool but trying to do it
without tearing the dustseals is tricky, the tool makes the job dead easy.

Re: Audi 80 rear brake caliper (UK)
 

On Sat, 18 Oct 2003 21:40:01 +0100, "Mark" <keep_it@thegroup.com>
wrote:

>"Jonathan Morton" <jonathan@removethisjonathanmorton.co.uk> wrote in
>> The tool is well worth the money, BTW.
>
>Thanks for the advice, I will get the tool tomorrow and have a closer
>inspection. Will let you know how I get on.
>Cheers.

When you see it and the price, you may decide to just cut a piece of
3mm scrap sheet to do the job. Or drill two holes in a length of
square bar to take pins that engage the slots. Or abuse a pair of
needle nose pliers - though if it is sized this will be major abuse.

--
Peter Hill
Spamtrap reply domain as per NNTP-Posting-Host in header
Can of worms - what every fisherman wants.
Can of worms - what every PC owner gets!

Re: Audi 80 rear brake caliper (UK)
 

"Peter Hill" <peter@nospam.demon.co.uk> wrote in message
news:n785pv83h7kdfoihd1hiha03ads00jc2sp@4ax.com...
> On Sat, 18 Oct 2003 21:40:01 +0100, "Mark" <keep_it@thegroup.com>
> wrote:
>
> >"Jonathan Morton" <jonathan@removethisjonathanmorton.co.uk> wrote in
> >> The tool is well worth the money, BTW.
> >
> >Thanks for the advice, I will get the tool tomorrow and have a closer
> >inspection. Will let you know how I get on.
> >Cheers.
>
> When you see it and the price, you may decide to just cut a piece of
> 3mm scrap sheet to do the job. Or drill two holes in a length of
> square bar to take pins that engage the slots. Or abuse a pair of
> needle nose pliers - though if it is sized this will be major abuse.

I did read about using long-nose pliers but with it been my first
attempt I wasn't sure how much pressure to use at the same time
of turning the piston, and knowing my luck I'd knacker the thing
completely. My local Halfords didn't have the Sykes Pickavant tool (£20)
but a nearby motor factors had a similar tool (think it was called
Laser) for £14.95 which I must say is a well worth investment and a good
tool to have.
Really made the job easy.

Re: Audi 80 rear brake caliper (UK)
 

"Duncan Wood" <freenews4@dmx512.co.uk> wrote in message
news:oprw9dydyi1fw2bx@news.demon.co.uk...
> If the piston moves back in with the tool then it's fine. New pin kits
> aren't particularly expensive &they're easy to fit. If they rotate
> easily you can screw the pistons back in with a bodged tool but trying
> to do it without tearing the dustseals is tricky, the tool makes the
> job dead easy.

Job sorted and everything is working fine. The piston went back easy
(which was a pleasent surprise) and the handbrake is also working good
and holding evenly on both wheels on the 3rd notch of the lever. I gave
everything a good going over with copper grease.

Having had the chance to inspect underneath, I notice a very small drip
of brake fluid which seems to be trickling down from what I think is the
rear load regulator valve (the thing that pivots on a spring attached to
the rear axle). Looks like 4 brake pipes go into this but I can't yet
tell if the leak is from one of the pipe joints or the main regulator
assembly. Anyone know if these regulator things are prone to leaks?

Re: Audi 80 rear brake caliper (UK)
 

On Sun, 19 Oct 2003 19:45:45 +0100, Mark <keep_it@thegroup.com> wrote:

> "Duncan Wood" <freenews4@dmx512.co.uk> wrote in message
> news:oprw9dydyi1fw2bx@news.demon.co.uk...
>> If the piston moves back in with the tool then it's fine. New pin kits
>> aren't particularly expensive &they're easy to fit. If they rotate
>> easily you can screw the pistons back in with a bodged tool but trying
>> to do it without tearing the dustseals is tricky, the tool makes the
>> job dead easy.
>
> Job sorted and everything is working fine. The piston went back easy
> (which was a pleasent surprise) and the handbrake is also working good
> and holding evenly on both wheels on the 3rd notch of the lever. I gave
> everything a good going over with copper grease.
>
> Having had the chance to inspect underneath, I notice a very small drip
> of brake fluid which seems to be trickling down from what I think is the
> rear load regulator valve (the thing that pivots on a spring attached to
> the rear axle). Looks like 4 brake pipes go into this but I can't yet
> tell if the leak is from one of the pipe joints or the main regulator
> assembly. Anyone know if these regulator things are prone to leaks?
>

That's the rear load reg. I've never seen leak but that's cos I normally
seem to have to change them because they've jammed. YMMV.