2001 Rear disk - bolt stripped

[scargoz]

I have a 01 Neon ACR - 4 wheel disc brakes...

So for about a year there is this terribly lou rattle from the back
driver side when going over bumps. So I notice (finally) that it
disappears with a light application of the brakes (I had thought it was
loose body stuff after a parts delivery pickup clocked the back bumper
and never bothered to investigate).

I finally checked it out after changing the oil the other night ...

The topmost 10mm bolt that holds the caliper to the hub/knuckle is
clearly 5+ mm "longer" than the lower one. It is not in all the way...

Poking around some more, the inner pad is the noise culprit - it is
just in there free to rattle about ...

The pad clip that holds position onto the piston had fallen or rattled
off - hence the major noise - new pad is needed. Do note, the pads are
barely worn on this side. Barely - even for a rear brake. I do need to
compare this to the other side to see if they are even - I suspect the
driver side has never really contributed much to the stoppage of the
car.

(note - front brakes are still original at 80K miles - this car is
driven like a wuss to minimize costs, save for a track time in
Brantford Ontario a few years back, a few drag strip passes, and
maybe 1 autocross, just replaced the OE tires 2 months ago).

Back to the bolts ... the top is as tight as it gets, something is or
had clobbered the threads, or they were never there all the way. The
top one doesn't thread into the bottom hole, and the bottom
doesn't thread into the top more than 1/4 inch or so. Something is amok
This is how the car came from the factory!

Wish I had noticed this a looong time ago - would have fixed it asafp,
and saved one Volvo a good smack.

Anyway -- how to fix? I'll need a tap & die set? One that can complete
or fix the threads for the bolt, and clean up the bolt. Any
recommendations on this new for me tool?. Or, should I get a new bolt
(how to ask the parts guy for that?) or ... any suggestions are
very welcome.

Thanks!
-johnj

[rymeswithorange]

just buy 2 new m10 x 1.5 bolts the same lenth as the old ones, make sure they are grade 8 or better, get them from the auto parts store, then buy a m10 x 1.5 spiral flute bottoming tap from a tool place,should only cost $10-$15. run the tap through the holes to clean up the threads and install the new bolts.

[dodgeneonACR98]

Is one of the holes stripped out? Or is it just mangled from the loose bolt?

If you can get a tap like Rymeswithorange said and just clean the threads up and re shape them from being beat up a tad you could get by with a few tools and bolts from a parts store.

If there is no meat left inside the bolt hole (stripped out) you might try to get a Helicoil kit and repair it! To use a helicoil you will have to get a drill bit (to match the helicoil) a tap and a helicoil driver. What you do is drill it out and tap it to fit the size of the helicoil. After the helicoil is installed you want to use a small screwdriver and break off the little peice at the bottom of the hole. (This is the peice of the helicoil that the driver used to thread it in.) After this you can use some new bolts and bolt it back up.

Other than that you might need a new rear caliper! Good luck.

[rymeswithorange]

yikes,, i dont like those helicoils, better to buy a 9.5mm drill and a m11x1.5 tap and go up a bolt size,,again make sure whatever bolt you use is grade 8 or better

[n-gin]

Coule of things:
The helicoils are better than origial, Going up a bolt size will not allow for the slide to fit, and finally the original bolts that hold the caliper on are grade 5. When you apply brakes it creates a harmonic and harder bolts are more prone to break rather then strech. Non the less grade 8 will work. Happy wrenching.

[rymeswithorange]

cool,,i didnt know that about brake parts using softer bolts, totally makes sense,,i just assumed automotive grade. personally i would rather drill the slide for clearance and have a bolt in a tapped hole than trust a helicoil,,just my opinion, even though i have used them successfully, i just dont like them,lol (have to dissagree about "better than original" though,,im a machinist,,picky picky,,lol)

[scargoz]

I appreciate the feedback ... I may finally get to it this weekend.

The bolts were in tight when I disassembled/removed the caliper,
so from the factory, the bolt was inserted/tightened, but it tightened
well before reaching the proper depth. So - the bolt was not moving,
and I'm original owner - so the first to remove it.

The die/tap too sounds like it might work. I don't recall vividly if there
were apparent threads, or no threads where the bottom of the bolt
should fit.