Hi Peter, Is this more or less the same procedure for the calipers on a W124 ?
I'm starting to make my Spring time to do list. :-) Thanks, Ed 300E 2009/2/28 Peter Frederick <psf...@earthlink.net> > Yeah... > > Remove caliper. Pry out the fried dust sheild. Note location of shield > and the raised portion of the piston lip. Clean the caliper completely with > a brass brush and brake parts cleaner -- don't get any crap into the brake > line fitting. You must have the pad slots completely clean anyway. > > Since these are in decent, if leaking shape, you can then pry off the torn > and leaking dust boot and use a pair of screwdrivers to pry up on the piston > and remove it (there are two, one on each side -- do one at a time). > > Be carefull to pry straight out. You can also use LOW air pressure by > clamping one piston at a time with a C-clamp to pop the other one out. 10 > psi, Max,-- > > When the piston it out, clean it up with a shop rag and some brake parts > cleaner. NO ABRASIVES. Should clean up well. If corroded, scratched, or > gouged, replace the caliper. Pits above the seal with the piston all the > way in can be ignored, though. > > Inside the bore of the caliper is a square seal in a slot. Use a bent pick > to remove this -- likely rather hard by now -- and DO NOT GOUGE THE BORE. A > scratch will require a new caliper.... > > Clean with brake parts cleaner, and if there is rust and corrosion built up > above the seal slot, you can remove it with ScotchBrite IF you do not touch > the rest of the bore. NO ABRASIVES IN THE BORE -- the caliper will stick. > I like to use a hard scraper instead. There must be clearance for the > piston -- must fall right down to the seal, no drag. > > Flush VERY well if you had to use scotchbrite on the outer lip -- any grit > between the bore and piston will cause it to stick. I prefer to scrape with > a hard scraper, but you still have to clean like a nut. > > Install the new seal after coating it with brake fluid. Don't use anything > sharp to push it in place, or you will have to get a new one when you slice > it. Wipe some brake fluid onto the piston and place it in correct > orientation (which is why it's nice to do one at a time) and press it down > with a thin piece of wood put through the caliper. You may need to rock it > back and forth a tiny bit to get it over the seal initially, but it will > drop down with minimal pressure once the seal is on the chrome part of the > piston. > > Install the new dust boot -- this is the worst part as you wont' have the > fancy tool to press it down over the outer edge. A thin wood strip works > well for me, but it's still a pain. > > Place the new heat shield into the piston and carefully press into place. > Be sure you have it aligned correctly before you push the center down, as > it's impossible to get them back out without bending them all to bits. > > Repeat for the other side. > > Install calipers and new pads. Put a smear of anti-seize on the back of > the pad where the piston touches, and along the sides of the backing plate > on both sides (NOT on the friction material). This prevents squeal and > keeps the corrosion down on the pad slots so the pads don't stick. > > And, ALWAYS, replace the rotors if there is a distinct lip at the outer > edge. There is very little margin for excessive wear on those rotors, and > if they are showing a distinct lip, the backing plate on the pads will hit > the anti-rattle spring before the friction material is worn off. When this > happens, the pistons will become cocked in the bore and stick, causing the > brakes to drag. The resultant heat will fry the dust boot, allowing dirt > and water into the bore, and wreck the caliper. > > Peter > > On Feb 27, 2009, at 9:15 PM, Curt Raymond wrote: > > Anybody got a step by step on caliper repair? >> Hammie the '83 240D went to my Indy's last week for the brake pedal going >> to the floor. Turns out the rear calipers which I didn't replace last summer >> were leaking bad. One of the front calipers I did replace last summer is >> leaking a little... >> I had him replace the rears, I figure I'll deal with the front myself. >> >> Originally I'd planned to rebuild the old fronts anyway so I figured this >> was a good way to start, then take the ones I'd bought and shove 'em up the >> kid's nose at Advance Auto. Then it occured to me I'd probably be better to >> throw a rebuild kit into the leaker myself. I'll probably even learn >> something before I'm done. >> >> -Curt >> >> >> >> >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: <http://okiebenz.com/pipermail/mercedes_okiebenz.com/ >> attachments/20090227/6f7d063e/attachment.html> >> _______________________________________ >> http://www.okiebenz.com >> For new and used parts go to www.okiebenz.com >> To search list archives http://www.okiebenz.com/archive/ >> >> To Unsubscribe or change delivery options go to: >> http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >> > > > _______________________________________ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > -------------- next part -------------- An HTML attachment was scrubbed... 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