7mm allen bolts on front brake calipers - stock?

[Spikedog]

I did my front brake pads a couple of weeks ago. I had my trusty Chiltons to help me, but this was my first time doing this job on my '96 Merc Misty 2.5L. The book said the caliper bolts were a 40 tork, so off I went to the store after figuring out I had only 10, 20, and 30 tork drivers.

The 40 tork wouldn't work, so I got out a mirror and saw the bolts were an allen head design. All my allen wrench sets, and not one would work. Apparently most metric sets go 5, 6, 8. I lucked out with a Craftsman 7mm on a 3/8" drive socket, and got the job done. Still, 3 trips to the parts store I consider a moral defeat.

Is the book wrong, or did I get an aftermarket bolt? I had Midas do the last brake job back in 2000.

 

[blu_fuz]

Every front caliper mounts to the knuckle with hex head bolts. Rear caliper brackets mount to the knuckle with torx head bolts unless they were changed by someone in the past.


The caliper slide pins could be allen or torx I guess. I remember most being torx, but it's been awhile. I have had some allen ones too, but not sure why they were different.

 

[BrApple]

book is wrong. As far as I know all the slide pins are 7mm.

 

[DanMyers]

Both Contours I have owned have had Torx from the factory in the slide pins (you can tell by the yellow loctite on them) the replacements sold at Advance Auto where I work are all 7mm allen. They have red loctite on them.

 

[Spikedog]

Thanks for the replies.

I've heard some metal on metal grinding from the new pads, and took off the driver's front tire last night. I found the shim that came with the new brake pad (outer pad) had come off, slipped down, and was busy trying to shear through the rotor. There were a couple of tabs that were almost gone off the bottom of the shim, and a groove worn into the rotor. Looks like the shim was tack welded in a couple of spots to hold it in place. I guess maybe a 1/4" of metal was gone off the bottom of the shim. Maybe I should turn the stereo down once in a while, huh?

I put the pad back on without the shim. The brakes seem to still work OK, and the passenger side new pad shim doesn't seem to have shifted (yet). I heard a little squeaking / groaning from that brake on the way into work this morning while making turns - I hope that will go away eventually.

 

[Spikedog]

Update - the brakes are working fine. About 2 weeks to break the new pads in. I guess taking the backing plate shim off the pad isn't a show stopper.

 

[amc49]

Backing plate is only for squealing. You can repeat the pictures of high end pads by angling the ends like they show in pictures, the angle is for squeal too. Don't need to do both ends, only the side the rotor rolls into first, or the back of caliper. I grind them on a bench grinder, all of five minutes work.

The leading edge of pad or shoe meeting the rotor at a right angle is what makes squeal, reduce angle to not let that corner edge dig in and squeal/squeak disappears.