S3 master cylinder

[ian]

Rear calipers replaced with refurbished units, although all the shims fell out, 3 on one side, 4 on the other? not to sure which one goes where. Any ideas Scarpia?   I filled the master cylinder on the car with dot 4 brake fluid bleed through the recommended way with no problems, using an old easy bleed system I had knocking about. Air filter and oil filter sourced. Forgot about a sump plug tool, any alternatives? Is the plug used by any other marques or will I have to buy the right one? Sump sits very low doesn't it!

[Scarpia]

make sure you watch for the shim washers that fall out from between the calipers and the mounting points when you remove the bolts

The problem with experience is that you gain it mostly just after you needed it. Like I said , the same thing happened to me. I seem to remember using feeler guages, a bit of trial and error, wheel spinning to check free movement and tiny blobs of copper grease to glue the washers in position while I put the bolts in. Sounds right anyway......
i'll check the book later for the spacing required, pad to disc and tolerance allowed.

[Richard Fridd]

i normally use a suitable hexagonal wrench to rotate the sump drain plug - being careful not to lose the associated copper seal unless i have a new one to hand-

[Neil Lewis]

make sure you watch for the shim washers that fall out from between the calipers and the mounting points when you remove the bolts

I seem to remember using feeler gauges, a bit of trial and error, wheel spinning to check free movement and tiny blobs of copper grease to glue the washers in position while I put the bolts in. Sounds right anyway......

I also used the trial-and-"improvement" method (political correctness gone mad) and just put the shim in so that there was as equal amount of space on both side of the disk between itself and the calipers.  Being as though there are pistons on both sides of the disk, so long as you have space both sides, the calipers will never move closer to the disk and start to rub.  So I say forget the book and just go by eye and feel.  It works for me.

Most importantly, don't forget the tab washers under the bolt heads.  I did and a front caliper came off on the M3 and nearly ruined a wheel.  The bolt of course was lost and there wasn't another M10 fine bolt I could borrow from elsewhere on the car so I had to come home on an RAC truck.  Most undignified.

Neil