What to put on back of brake pads to stop squeal?

[chrisntam]

........Back in the day, we used to put on silicone type stuff called "disc brake quiet", it would dry to a rubbery like feel.

Went to the parts store today, they now recommend grease (for this type application).  All the same grease to put on the caliper pins, the bushings, all moving parts, including the back of the pads.  Says its good up to 425 degrees.  Seems like grease on the back of the pads is a bad idea.

What are we doing these days?

Anyone ever do a 30 day brake job?, that's what mine is looking like.........  Do a little work, order parts.  Get the wrong parts, reorder.  Too hot to drive the ol' car anyhoo.

[Scot Minesinger]

The brake pads get hotter than 425'F so do not use that grease.  There is a product out there, but I do not know what it is.  Hope someone chimes in, or a lucky google search will help.

Yes, I certainly am familiar with the 30 day job that should take two.  However that is what some of these jobs take and why we need to do them ourselves sometimes.  Your project is a good example.  Another one is needed to replace the trans cooler lines on a 72 Eldorado, and they sent 5/16" lines, as the originals were cut and spliced with rubber.  The correct lines are 3/8".  The smaller tubing diameter represents a 30%reduction in coolant flow.  Heat is what takes out these TH425 or Th400 trans.  Understand sometime between 73 and 76 the lines were 5/16", but not going to install less than factory and in 72, 3/8" lines were installed.  Certainly was not going to compromise here.  Had to wait like two weeks for these lines after the replacement set arrived which was another set of 5/16" set-very frustrating. 

No mechanic shop can let a car sit in a protected covered space for two weeks for this kind of a repair and so they would have made the smaller lines work with adapters at the trans.  The replacement radiator had the female 1/2" flare threads to accept 5/16" lines, so had to find adaptors to receive the 3/8" with 5/8" flare nuts.

Your repair will be done right.  A job done right is it's own reward.

[76eldo]

If you cannot find some high temp grease for this purpose just use the disc brake caliper hardware grease and call it a day. They are probably dry as a bone now so they squeak. Just  a dab on the sides of the shoes where they rub on the backing plate is fine. The other stuff you mentioned is supposed to glue the back of the pad to the caliper piston to avoid rattles when the brakes are retracted. That's not what you are trying to do here.  I normally use plain old chassis grease or Lubriate and my brakes don't squeak.

Think in terms of what they did in the 60's and 70's at the corner gas station.

Brian

[Jon S]

You don't want grease that will break down and contaminate the pads. Just spray this on the back of the pads - a light coat:

["Cadillac Kid" Greg Surfas 15364]

Chris,
Second on the no grease on the pads. I've not used that particular material Jon is showing, but there are several brands of this type material for coating ON THE BACK SIDE of the pads. What it does is form a resilient "bed" for the disc pad and keeps them from "singing".
Greg Surfas

[Bobby B]

Chris,
Hi. Disc brake pads get a thin wipe of moly-type grease on the back of the pads, usually supplied with good brand pads. Pins, bushings, and moving parts get a silicone-type grease. Both these application specific types of grease are available for $1.00 in small packets at the counter of your local Advance Auto Parts or Autozone, so there's no need to buy large quantities if your not doing this for a living. In the rear shoes where they contact the backing plates and the "self-adjusters", I've always used a thin wipe of anti-seize without any problems. Hope this helps.
                                                                                                 Bobby

[Jon S]

The spray I recommended not only eliminates the squeal; it is sticky and prevents the pads from rattling in the calipers.  Unlike grease, there is no chance for pad surface contamination.  For drum brakes, I coat the backing plate high points with high temperature grease.

[Bobby B]

Never seen grease on a pad or rotor by using the recommended supplied grease from the manufacturer and applying it as instructed. The "grease" they supply sticks like glue.
                           Bobby