Brake Pad rattle - retainer clips?
 

Hello all,
We had our 2004 Mazda 3 serviced by a bad garage down the road a few weeks ago and we now have terrible clanking / rattling. It seems to be from the back even at slow speeds. They had - among other things - replaced all the brake pads.

Yesterday we tried driving over rough ground with the brakes slightly engaged and there was no rattling. My mechanical engineer brother-in-law reckons the retainer clips might be missing from the rear-inside pads - those inside pads have a bit of 'play' in them. They move about, unlike the outside ones which have clips.

What do you reckon?

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The bad garage said it was a busted front shock and bearings. Not trusting them anymore, we got another garage to look at it and they just replaced the front shock - bearings seem fine, but they couldn't find the rattle source!

The crap garage have a track record of forgetting to put things back on the car like air filters! - and just generally forgetting to do lots of stuff.

If you're still reading :) - they also go ahead and do lots of work without asking first and then present you with a BIG bill.

I'd like to be able to say "look, you seem to have ALSO forgotten to put on the retainer clips when you replaced the pads - please do it". I also don't want them squeezing any more money out of us,

Cheers everyone,
John

They probably swapped the inner and outer pads. The inside pad on the rear has a spring to press it away from the caliper. The outside pad has no spring on it, and instead there is a spring on the caliper to hold it towards the center of the wheel.
If the pads were swapped the inner pad is floating in free space and could rattle.

This is an easy swap, should take 30 mins or less just to pull the caliper, swap the pads and put them back on.

The fronts can't be mixed up like that since one has a clip that attached to the caliper cylinder, and can't be put on the other side by accident.

Wow, I never knew that. Thanks Dave. :)

I wonder...Does the rear caliper compress by squeezing on it with a pair of vice grips like the front wheels, or do you have to screw it in, like on the rear of an RX-7?

Hi Dave, nothing would surprise me with these people.

They 'fixed' the pads today by 'lengthening' them (squeezing in a vice) and trimming them. All sounds very non-standard if you ask me.

This morning they said
"If he said it's the bearings - it's the bearings".
I explained about the loose pads.
"Oh, there's a loose tail plate light here" (no there wasn't)
We did a test drive.
"Yep that's the rear bumper"
(so not the bearings anymore then. Glad we didn't let them replace those)
I said, drive over that speed ramp with the brakes on...

No rattle.

Idiots. Got the car back, seems fine. Wonder if they sabotaged anything else?

You know, we drove hundreds of miles on Motorways over our 2 week holiday with those brakes.

ha, so they made the pads drag instead of float in the caliper bracket to keep them from rattling... That is what happens when they corrode and then seize in place - you'll have brake drag shortly if that is their solution.
So i'd have them fix it properly, or maybe get your hands dirty so you see what is going on. That's how you can make sure it's done right - do it yourself, maybe with the manual handy :)

Eggynatey - they turn in, I think ALL rear disk calipers need to turn in like this - because the one piston is used for an e-brake, so it needs that screw adjustment to keep tight.
I just made a tool for mine over the weekend, just need two small bolts (0.2" diameter pins max) on 0.75" centers attached to a handle. Steel is best for this, but you could figure it out with wood as well.

Good luck.

Jesus Christ. I might have known they'd do something stupid. Next time we'll replace the pads ourselves. I'm going to buy a manual and take a leaf out of my dad's book.

In the old days - dads used to fix their own cars.

There's a good chance they always do something stupid... which is why there's a scratch inside one of my door sills - something during an inspection of my car.
If you do it yourself and make a mistake you'll know immediately, cause you'll remember how you put it together and if it may have been backwards - like the pads above.

You should be able to look from the outside of the car and see if the outer pad has a spring on the outer side, towards the caliper... it shouldn't - but you don't need to take anything apart to verify this is the rattle problem.