36? 38? Rear calipers? Wrong parts?

[Mike Arman <armanmik@n-jcenter.com>]

>From: donohue@azstarnet.com (Terry Donohue)
>Subject: Rear Calipers-Wrong Pistons
>
>Finally decided to replace the rear calipers (Girling) on my '90 200TQ for
>the usual reason-no parking brake.  After some calls to determine that new
>ones were $420 each, I ordered a rebuilt pair from Blaufergnugen at $110
>each.  Got them two weeks ago, but careful inspection showed they weren't
>identical mirror image parts. 

Gold star for Terry! ALWAYS examine all replacement parts before attempting
installation. IMNSHE, when a monkey lad (tm) gets fired for destroying the
rear end of a Quantum with an air wrench, they send him to work in the
parts department where they only think he can do less harm. All replacement
parts are suspect, guilty until proven otherwise.


 There were slight differences in boss sizes,
>bleed screws, method for retracting piston, etc.  Then, I notice the number
>cast on the side-the left one was a 38, the right caliper a 36.  Yes, my
>car came with 38mm rear calipers; 36mm must be found on some other model.
(snip)

Right you are! The 36mm calipers are from the earlier 5000, 85 (I think)
thru 88 and not turbo. The 38mm calipers are for turbo and 200 models.

Right you are again! You are advised not to use one size on one side and
antoher size on the other.

Back to Blau (shame on them!) and explain it all carefully and slowly. Tell
'em to open boxes until they find you the correct part.

Incidentally, there is almost nothing in the $11 rebuild kit for the 38mm
calipers - a boot and a square-section o-ring. These are not difficult to
rebuild - the e-brake lever (usually stuck) responds well to penetrating
oil and patience.

Best Regards,

Mike Arman