the amazing magnifico
brett at cloud9.net
Tue Apr 9 17:45:22 EDT 2002
Watch, as he turns water to wine, lead to gold, and bad rear caliper
pistons to sparkling new ones.
Okay, so only the last one.
As you may recall, the piston on my rebuilt caliper was completely
trashed...or so I thought:
Well, it turns out that the "corrosion" wasn't corrosion at all. In
a semi-desperate last-ditch effort to just smooth it up and hope for
the best, I took a bic pen(the round kind), chopped it in half, added
a piece of tape or two, and screwed the piston onto that..then
mounted it on a drill(don't try this at home, kids. Professional
Unemployed Fool at work.)
So I'm turning it on the drill and gently polishing/sanding the
surface with 600 grit paper(really gentle stuff.) I notice a kinda
funny smell, and...what's this? That corrosion seems to be going
away a little bit too quick. Hmmm.
I take it off, and sure enough, it's gone from some spots, and in
others, it's now completely smooth. Hmm. I grab a bottle of
alcohol, rub hard, and the stuff goes away, revealing a completely
perfect chrome surface!
I finish off on my sanding job, use a little 3M marine metal
restorer+polish(great stuff, btw...just a very aggressive polish so
be careful on soft metals) and then finish off with a cleanup of
alcohol and a clean rag.
Guess what? Mix 'em up and around, and hand 'em back to me, and it'd
take me a few seconds to figure out which one is which. The 600 grit
paper took out all the surface scratches(which were -very- shallow)
and the polish compound restored a nice almost mirror-like finish.
Well, I'm just pleased as pie :-)
Caliper guide pins have just been finished, too..though they took
more work. For the most part it was just a really rough surface on
'em, so I turned them and polished down the pits and the notch that
had formed(the notches were on the caliper that seized/was wearing
unevenly/etc)...needed to start with 400 grit and work my way up.
Cleaned out the holes for the guide pins completely, and ran a bit of
500 grit paper in the holes to try and work down any burrs that might
have caused the notch...relubed with Mobil 1 synthetic grease(bright
purple of all colors, how odd) and tada, you have to press fairly
hard at an angle to get the guide pins to -start- to bind up, but I
don't think in normal use they get pressed that way...
Calipers look great; primer coat of Rustoleum primer after the
complete bead blasting down to bare metal, followed by flat black $3
"high temperature" engine paint("with ceramic!")...and they look
mighty fine. Here's hoping that the paint didn't screw up tolerances
between the carrier+caliper etc, and/or won't get rubbed off in the
first hour of use :-)
"They that give up essential liberty to obtain temporary
safety deserve neither liberty nor safety." - Ben Franklin
More information about the 200q20v