front brake squeal

[German Dude]

I have been gathering so much useful information from this page for months now. It's really great. I guess it's time to start asking questions now myself.
 
After a major brake overhaul (new lines, hoses,rear brake pads, master cylinder, and booster) everything is great but I hear a squeal which seems to come from the front brakes, increasing and decreasing parallel to speed but gone when applying the brakes.

As the front brake pads were new the guys in the shop didn't do anything about them.

Could this squeal come from the brake piston/brake pad connection, meaning I could get rid of it cleaning that area and applying some  
"Kupferpaste" (I don't know - would that be "copper paste" in English?).

I would like to see that squeal gone, because other than that, the car (aka little red lightning) is pure joy. Too bad Germany is having such a crappy summer...


Juergen
64 230SL #2933, 4sp
93 Citroen XM station wagon

[rwmastel]

Juergen,

Hi.  I rebuilt the brake calipers, replaced the rotors, pads, flex brake lines, and wheel bearings on the front end a couple years ago.  I have always had the light squeal that you describe.  At the time of the work, I did not know about the paste that can be applied between the caliper pistons and the brake pads.  I assume that is all that is needed.  I just have not bothered to do this yet.

Last week my front wheel or wheels started to make a very bad sound.  I got home safe, but I have not taken the wheels off yet to see what happened.  It may be an "opprotunity" to apply the brake paste while other parts are out for replacement!

Thanks,

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[graphic66]

My front brakes squeeled after I replaced them even with the antisqueel paste applied. I took them back out after some advice from some fine internet advisors and filed the edges of the metal backing plates on the pads so they moved freely inside the caliper and applied very sparingly antisieze compound to the edges of the metal on the pads where they contact the caliper. I also used the antisqueel compound on the back of the pads and the face of the piston. The antisqueel compound should dry before reassembly. My brake pads were definitly mounted on metal backing that was just a little to large and bound in the caliper, filing them to fit really helped them to run cooler and stop squeeling. The pads should drop right in with no binding to move freely within the caliper.

[George Davis]

Juergen and Rodd,

the brake anti-squeal paste or whatever it's called is worth a try.  Brake squeal is usually from the pad/piston contact area.

Good luck!

George Davis
'69 280 SL Euro manual