[Biturbos4] Rear caliper pistons on B5

[Jonathan Conta]

I do have the Bentley manual - I got to the section that said "Use VAG tool 3272 to retract piston" and said WTF.
The tool I got from Pep Boys looks very similar to the one from Germanautoparts.com - I took off the handle and added a jam nut so I could get some more torque on it.
 
My concern over sticky pistons came from the fact that the front pistons retracted with a fraction of the effort the rear ones required, though this appears to be normal from what other people have said.
The brakes appear to be working normally now - I did a careful seating of the pads for the first ~50 miles once they were on, and have done minimal hard braking since then to ensure they don't glaze before they get fully broken in.
 
Thanks for the links to some alternate tools though - might invest in one for next time if I can't rent one.
 
JC


northrup <northrup at crazybug.com> wrote:
Since i'm here on my computer, I just checked the bently manual for 
the S4 (worst P.O.S. that only installs once from CD and has no paper 
equivillent, not to mention that it is cryptic at best by comparison to 
others, and my computer is not in my garage).

All it says is to use the $100 VAG tool 3272, shown here:
http://www.audiworld.com/tech/wheel2.shtml

It says that the piston should be screwed back into the caliper, while 
pressure is applied to the piston. Both the Lisle I mentioned in the 
previous message and the VAG 3272 will do this. 

In the caliper rebuilding section of the manual (47-17) it shows a picture 
of the piston & threaded spindle it threads into. It looks as though it 
should screw on. If you were screwing the piston on while applying that 
pressure, perhaps you are OK? 

I would start your assessment by getting someone to step on the brake 
pedal and see what happens to the rear calipers. If all seems fine and 
you decide to drive with them, I'd also keep a watchful eye on the rear 
pad & rear rotor for proper and even wear. Certainly if there is no wear, 
or very little wear, they are not working properly.

wilson '00s4

On Sun, 2 Jan 2005, Grant wrote:

> Ahhh, I see you also don't have the shop manual. :-)
> 
> Every Audi made since about 1980 has required a giant hex key to 
> "screw" the rear calipers back in.
> I suggest you buy or borrow one.
> 
> I also dont have the bentley for the '00-03 S4, but I could dig up my 
> old '84 or '91 manuals if you need me to peruse them for you. Let me 
> know.
> 
> Not sure if any damage can come of the brute force method. Never had 
> the heart to do it. When I faced the same problem back on my 1984 
> 4000q, I put the old ones back in until I got the right tool.
> 
> Grant
> On Jan 2, 2005, at 9:11 PM, Jonathan Conta wrote:
> 
> > Apologies ahead of time if this has been covered - I'm new to the list.
> >
> > I spent a day this past week swapping out my stock pads (2000 S4 
> > otherwise currently unmodified - yet....) for some Mintex "red box" 
> > pads, both front and rear.
> > When changing the rear pads I was able to get the stock pads out 
> > without a problem, but when I went to compress the caliper pistons to 
> > fit the new ones in, I had a hell of a time getting them to retract 
> > back into the caliper. I bought one of those pad compressor tools at 
> > Pep Boys and nearly ruined the thing putting so much torque on it 
> > pushing the pistons back in.
> >
> > Has anyone else run into this? Or am I staring some 
> > sticky/about-to-freeze caliper pistons in the face? I did eventually 
> > get them back in and the new pads on, and I must say my initial 
> > experiences with the Mintex pads have been outstanding - much more 
> > even braking, less "grabby" than the stock pads, and significantly 
> > less brake dust.
> >
> > Thanks much,
> >
> > Jon
> > _______________________________________________
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> > Biturbos4 at www.audifans.com
> > http://www.audifans.com/mailman/listinfo/biturbos4
> >
> 
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