Rear Caliper Rattle

I've been chasing an annoying rattle in the right rear of my 2002 Vivid for months. I've tightened everything in sight, banged on most everything, and zip-tied some wiring harnesses just to be sure. I still couldn't find it until tonight. I *think* it's my rear brake caliper assembly. If I grab the brake hose and move it, I can get the floating portion of the caliper to rock back and forth. Also, the rock shield behind the rotor sounds similar to the rattle if I bang on it. No bolts are loose, but there is play in the floating portion of the brake assembly. I don't actually need new rear pads, but they are old, perhaps original (~110k miles). I suppose if I replaced them, there would be more friction material taking up space so there might not be as much play.

Has anybody run across this before? Any other things I might have overlooked in that assembly?

Have you ever lubed the slider pins?

Not on this car, but I'm not seeing how that would help. If there's play in the assembly so it can wobble and make noise, how could it make a difference if the play could slide from one side to the other more easily?

Have you recently checked rear brake adjustment, with the allen wrench and such?

No! Good idea!

If the parking brake works why would you adjust it??

In the words of my Grandpa Harrison, "If it works don't Fuck with it." (Or something along those lines)

Lube the pins would be my first thing I'd do... YMMV

I had a "rear caliper rattle" once. It was a single loose lug nut. :punchout:

Update...I adjusted the rear brake as Walsted suggested and the rattle is gone. Easy peasy.

Jack up one rear corner, remove wheel, remove one 14mm cap on the back of the caliper (NOT one of the bolts holding the caliper in place), adjust the caliper using a 4mm Allen wrench until the pads grab the rotor, back off 1/3 turn, replace 14mm cap, replace wheel, remove jack. Repeat on other side. Done. Rattle gone!

You may find that this works for a while, then returns. If so, it is because the rear brakes are not "Self Adjusting" as they should. You can rebuild or replace them. If you decide to rebuild, I have a tool that will get to the c-clip that is way up in the caliper. Long nose c-clip pliers.

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Originally Posted by Avarice

You may find that this works for a while, then returns. If so, it is because the rear brakes are not "Self Adjusting" as they should. You can rebuild or replace them. If you decide to rebuild, I have a tool that will get to the c-clip that is way up in the caliper. Long nose c-clip pliers.

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NA and NB rear brakes are not self-adjusting.

^They're not? I think you're mistaken.

Maybe mine are magic.
Before I rebuilt the rear calipers, I would adjust them and they worked good for a while, then had to adjust them to get the E-brake to work again.
After rebuild, have not touched them in years. E-brake works like it should.

E-brake on mine has always worked, although I don't have to pull the handle as far up as before. As easy as it is to adjust them, I'd do that several times before rebuilding the caliper.

I have never seen any self-adjusting mechanism for the rear calipers any time I have had them off.

The parking brake actuates a gear that eventually turns and pushes on the piston to stop the car, the piston itself does move out with pad wear due to the special seal around it, as well as a doohickey inside the piston itself that's not visible unless you disassemble the whole thing. So it is actually self adjusting.

The hex adjuster is there to set it up initially as well as to back it off when you put in fresh pads.

To get it right you'd want to set the parking brake off. Adjust the hex adjusters to spec (get it to contact and then back it off 1/3), then mess with the parking handle/cable adjust to get it within 7-9 clicks. It should stay there through the life of the pads unless something else is wrong.

That has not been my experience through hundreds of thousands of miles and more than a few calipers. Hydraulics will keep the pad in place if you forget to put in the brake kit springs, but my experience is that if you don't adjust, the engagement point of the pedal will gradually lower. Maybe I shouldn't buy from O'Reilly or RockAuto?

Take a look at this article, especially at figure M.

http://miata.net/garage/ebrake/index.html

Not too sure what might be causing the pedal (or was it the parking brake to go higher and higher?) to drop lower and lower, but I'm thinking something is bad even with the rebuilt calipers.

That is very helpful, and apparently I have been buying crappy rear brakes for years.